CMS Pulls the Trigger!

CERN, CH–1211 GENEVA 23, Switzerland

Bulletins are available on Number 01-02 CMS internal information server: http://cmsdoc.cern.ch/cms.html 15 June 2001 CMS pulls the Trigger!

LABORATOIRE EUROP EN POUR LA PHYSIQUE DES P ARTICULES CERN/LHCC 2000-038 CMS TDR 6.1 CERN EUROPEAN LABORATORY FOR PARTICLE PHYSICS 15 December 2000 CMS

The Trigger and Data Acquisition project, Volume 1 The Level-1 Trigger Technical Design Report

The trigger and Data Acquisition TDR was submitted at the end of 2000. It was given general approval by the LHCC in March 2001.

CMS Bulletin 01-02

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CMS NEWS ...... 3 News from the RRB12 (23 April) ...... 3 News from the LHCC ...... 4 CMS Comprehensive Review (CR) at LHCC54 (1-5 Oct)...... 5 News from the Steering Committee Meetings of 7th May (SC33) and 11th June (SC34) ...... 5 Largest Single Element of CMS Arrived at Point 5 ...... 8 NA48 pins down Direct CP Violation ...... 9 CERN Relay Race ...... 11 Summary of the CMS Week 5 - 9 March 2001 ...... 12 Joint Session of Finance Board, CMS Management Board, and CMS Collaboration Board ...... 12 Technical Coordination, Schedule and Integration ...... 14 Magnet / Installation ...... 15 Inner Tracking ...... 16 Electromagnetic Calorimeter (ECAL) ...... 18 Hadron Calorimeter (HCAL) ...... 19 Muon Detector ...... 20 Trigger ...... 20 DAQ ...... 21 Software ...... 21 Physics ...... 23 CMS Documentation ...... 25 CMS Documents ...... 25 CMS Notes ...... 25 CMS Conference Reports ...... 25 Thesis ...... 26 Job Opportunities ...... 26 CMS Calendar 2001 ...... 27 Monthly Calendar ...... 28 CMS General Information ...... 29 Secretariat ...... 29 Useful phone numbers ...... 29 Procedure for newcomers ...... 29

If you have comments / suggestions please contact: Walter Van Doninck (Editor-in-Chief): [email protected] 2

CMS Bulletin 01-02

CMS NEWS

NEWS FROM THE RRB12 (23 APRIL) Tracker 7.4 Italy, CERN, The common session of the RRB took place on the Germany, France, USA 23rd of April, chaired by the CERN DG. The new schedule of the LHC was presented (See previous ECAL 18.0 Switzerland, CERN, France, USA CMS Bulletin). An important milestone is the adju- HCAL(HF) 2.0 USA, Russia dication of the dipoles in September 2001. At the December council we will have much better idea of Muon DT 2.8 Italy, Germany, Spain the overall cost of the LHC project: Machine, Com- puting and M&O. MUON CSC 4.3 USA, Russia MUON RPC 3.3 Italy, Pakistan, R. Cashmore presented a document prepared for Korea, (+) the RRB on M&O including preliminary cost esti- TOTAL 44.3MCHF mates per experiments. The proposed calendar is the following: CMS must now talk to the Funding Agencies and present a progress report to the October RRB. The RRB April 2001 : prepare draft MoUs. Agree on LHCC CMS Comprehensive Review will also be in arrangements for 2002. October and reported to the RRB. The aim should RRB October 2001: Comments on draft MoUs. be to have a final plan ready for April 2002 and the Agree on allocations for 2002. overall strategy should include looking for new RRB April 2002: Agree on final MoUs. collaborators, for extra money and possibly staging the detector. The 12th meeting of the CMS RRB took place on the afternoon of 23rd of April. In addition to the stan- Discussion on LHC Computing dard reports (Status of experiment and Budget The CERN Tier0+Tier1 facility must be a common matters) the agenda included a discussion on : the project between the experiments, with CERN-IT CMS Contingency plan, the Computing plans and playing a strong role backed by adequate resources. the M&O paper. Discussions took place in March with the SPC and Committee of Council on the basis of a paper Contingency Plan 'Building the LHC Computing Environment', and The RBB has been regularly informed about the so- CERN is now developing a plan for discussion dur- called CMS Contingency Plan. The CMS contin- ing the June Council week. A two-phase project is gency plan gives priority to critical path items by foreseen, 3 years for setting up the GRID and proto- shifting allocated funds around and finding new type infrastructure and 3 years for setting up the funds. A missing 10.5 MCHF have already been final LHC computing environment. Costing the covered in this way within existing funds. The RRB second phase is necessarily based on extrapolation. had asked for estimates of funds needed for CMS completion, including possible costs overrun and/ CMS IMoU for Core Computing & Software or lack of funding. The total funding shortfall is The LHC distributed computing environment is now 44.3 MCHF: hard to simulate. A series of tests of increasing Lack of funding (in MoU) 15.7 complexity is needed to reveal and resolve succes- sive levels of difficulties. To achieve this, two major Dollar/CHF exchange rate penalty 10 problems must be addressed urgently, the acute Extra work on surface 4 lack of software engineers and the need for proto- Overlooked/new items/cost over- 6.6 typing. runs According to March 2001 estimates, the needed ECAL cost overrun 8 manpower for CMS core software, in FTE software professionals, is: TOTAL 44.3 MCHF 2000 2001 2002 2003 2004 2005 2006 2007 This is <10% of the total cost, ≈3% due to lack of 12 16 29 40 43 44 46 42 ≈ funding, 6% cost increase/overrun. Despite recent increases in effort from Italy, France The deliverable items to be covered and the major and Russia, over two-thirds of the required man- contributors are: power is currently missing. No institutes are for- Deliverables Cost Major Contributors mally responsible for core software, so it is taken to be a collaboration-wide responsibility. The issue of Infrastructure 2.5 CERN, (+) missing manpower for experiments core software Surface Work 4.0 CERN, (+) has been emphasized in the Hoffman review. CMS

CMS Bulletin 01-02 believes a multilateral IMoU is the best approach to The intention to delay submission of the TRIDAS address this issue within the Collaboration. TDR until end 2002 was noted by the LHCC. Discussion on M&O paper Resistive Plate Chambers (RPCs) It is very important to identify the total and real In the closed session there was a review of RPCs in costs of running the LHC experiments. Present fig- all LHC experiments. The outcome of all the pre- ures in the M&O paper are indicative rather than sentations was inconclusive, and therefore there accurate. Items need tighter definition and catego- was some concern that there is not yet a universally ries need further consideration. Some costs may accepted construction technology. already be covered in the construction MoUs. Also, The LHCC was reminded that CMS will come to a cost estimates have to be revised in view of the new decision on the final construction technique (pri- LHC start-up date of 2006. marily an issue of linseed oil) in June and that Cashmore will set up a small group, consisting of developments on the muon trigger modifications the 4 resource coordinators and 3 or 4 members of which may result are underway for completion at CERN management, to produce clear definitions of the same time. the line items, definitions that will be included in ECAL the M&O MoU. With the help of the RRBS, he will also set up so-called scrutiny groups to examine the Encouraging progress on solving the APDs radia- collaborations' cost figures and guarantee their tion hardness problem were noted. Only after integrity. The scrutiny groups will have 3 or 4 delivery in April of large numbers of APDs with members nominated by the RRBs for each experi- the new wafer design will CMS be able to substan- ment, and 3 or 4 nominated by CERN common to tiate the design modifications. all experiments to provide uniformity. On crystal production, the factor 1.6 in production schedule from Russia, arising from the larger Summary ingots, is impressive. In conclusion R. Cashmore said that the estimated cost to completion of CMS will now be followed up Tracking in detailed discussions with the Funding Agencies The progress towards understanding the tracker with a progress report given to the October RRB. performance, and in particular towards addressing Half way through the project a 6 - 10% overrun can the issues related to the final Si layout compared be viewed as quite an achievement. Of course, the with the TDR (Si+MSGC) layout were reported to collaboration must try to reduce this before asking the LHCC. The good work which is underway, for more resources. within the new OO framework in CMS, to produce There is work to be done to get a coherent approach software which will confirm the expected perfor- to LHC Computing. On M&O, vital for the experi- mance, is fully appreciated. The work on the mate- ments, lots of homework is needed before October. rial budget of the Si tracker was clearly of a thorough and an on-going nature as the reality of engineering design proceeds. NEWS FROM THE LHCC CMS at LHCC52 (16-17 May) CMS at LHCC51 (21-22 March) CMS Schedule CMS General Schedule L1 milestones are almost final now, and L2 mile- Closed session presentation: the present funding stones are in their final stages of agreement shortfall was noted. The LHCC noted the post- between the management and the project coordina- ponement of the fixing of the final L1 milestones in tors. They should be frozen for LHCC53 (4-5 July). the light of the extra civil engineering delay. It is The committee is aware of the constraints which extremely important to maintain the schedules for form the basis of v31, namely the availability of UX detector components with contingency, or ``float'', and the fact that as much parallelism as possible is to ensure that there is enough flexibility to react to included in all aspects of installation. hitherto unforeseen problems in installation which Beam pipe are bound to arise. The L1 milestones should reflect this need. The new geometry in Be and the associated issue of Trigger TDR the pixel support given that optimisation is underway (as reported at LHCC51) of the pixel geometry, The Trigger TDR was recommended for approval. is noted. The examination of costs by the CORE panel Tracking: should be underway soon. The LHCC prepared the usual additional document and minutes in support The delays in the ordering for M200, in the hybrids, of approving the Trigger TDR. and arising from the problems in the mechanical EDR were reported.

CMS Bulletin 01-02

The LHCC will continue to follow the tracking per- 1. The status should compare directly with formance studies in subsequent meetings given the CR2000 present non-understood results which persist. 2. A focus will be on schedule problems ECAL 3. The intention is also to note successes The LHCC continues to note the difficulties in get- 4. Within the context of the detector schedules, a ting crystal production started related to procure- focus will be on achieving a clear picture of ment of acceptable quality in China, the non-final what is staged and what is missing which could electronics for M0' (full functionality but 4times be fixed with new resources; there is an expecta- noise), and on going troubles with the APDs. There tion that the consequences for physics of staging is a concern that the APD problem is still not finally and omission will be clearly presented. resolved. The LHCC will follow these delays with 5. It is the intention that the collaboration under special interest and concern in the context of v31 in CR will present as accurate an estimate as possi- the coming months. ble of its test beam needs in coming years. Muons - DT In order to prepare the CR the week of 17 Septem- ber before the CMS week has been reserved for the There is a concern with the logistical problems in Annual Reviews and rehearsals for the CR. The fol- establishing DT production arising out of distribu- lowing agenda is proposed: tion of technology (Dubna) and availability of I- beams (Protvino). CMS should report on the result Mon 17 DAQ (afternoon) of the Manufacturing Progress Review (MPR) in Tues 18 CPT July. Wed 19 ECAL Muons - CSCs Thur 20 Tracker Fri 21 Muons The problems over LV supply and electronics Sat 22 HCAL (ALCT) continue to concern the LHCC. Mon 24 Trigger (morning) Muons - RPCs The CMS intention to have a decision on choice of NEWS FROM THE STEERING COM- RPC technology at LHCC53 now becomes also an MITTEE MEETINGS OF 7TH MAY issue of interest to other collaborations. The LHCC (SC33) AND 11TH JUNE (SC34) will expect to see clear justification for the decision RRB12 Follow up taken. A Funding Shortfall of 44 MCHF was indicated at HCAL the last RRB. CMS should start bilateral discussions HB and HE are in ``good shape''. Problems con- with funding agencies. For the October RRB we cerning FE ASICs persist (QIE) and are still a con- should finalise the costs, prepare scenarios for vari- cern. The schedule for the HPD now is on the ous levels of missing funds and examine the phys- critical path. HF completion is extremely time criti- ics consequences. cal. The LHCC notes the proposed changes in the M&O: L. Foa has called a meeting in Catania of all fibre configuration and read out geometry in HF, PMs and SRMs to start dealing with Category B and the proposed elimination of the tail catcher. If costs. the decision to go this way, and thereby to down- scope the HF capability in the very forward direc- LHC Computing: CMS has to prepare a draft IMoU tion, is taken by the collaboration, quantification of for October, specifying the need for Software Engi- the changes in terms of physics performance must neers. CERN prepares an integrated plan for LHC be reported. Computing to be presented in June Council: LHC Computing Grid Project. Computing Baselining of v31 Milestones The project structure (the CPT matrix) is a sensible All subdetectors should finalise their v31 mile- approach. CMS should provide further justification stones in the CMS week in Catania. A summary for the manpower requirements. On project moni- meeting to conclude v31 will take place 16:00-18:00 toring, it is requested that v31 includes a set of on Weds 20’th June. We need to present milestones computing milestones in a manner similar to other to the LHCC referees on Mon 2 July. projects. RPCs Layout CMS COMPREHENSIVE REVIEW (CR) AT Barrel RPCs: The following changes to the RB sys- LHCC54 (1-5 OCT) tem were approved in the last MB: We received the following guidance: YB0 : move tail catcher iron to allow RB0/1 to be installed on the coil side and integrated with H0/1.

CMS Bulletin 01-02

YB 1s & 2s : integrate RB1s with HO. Muon-CSCs These changes improve the high pt acceptance (by Nominal rate of chamber production at Fermilab about 3%), but it was realized later that magnet tie- achieved. Chamber production is on schedule. bar anchor points and cable layer on solenoid trap PNPI and IHEP sites started pre-production. FE- RB0/1! In addition mechanics and readout changes Electronics production started, costs under control. to RB1 are substantial. It is therefore proposed to Rad-hard LV-regulators and trigger boards on the abandon the entire change to RB1. critical path. Endcap RPCs: The aim is to provide an extra layer Schedule an ME MPR towards the end of the year. (RE2a is best) at high luminosity and decouple Tracker RE1/2 installation from the critical path towards YE cabling. The baseline solution is a standard Tracker will prepare a new list of milestones. Com- RE1/2 RPC that is installed below the cable tray. pared to the last update (04/00) milestone 200 and Increasing YE1 to YE2 separation is possible as an start of module construction there is an integrated upgrade. It is proposed to re-instate YE4 and RE4 delay of some 4 months. The critical path is driven with no change to basic RE design layers 2-4. A by the procurement of the populated FE hybrid. A double RE2 using “thin technology” is possible as large fraction of the budget must be committed an upgrade. during 2001 /start of 2002. Logistics for module production are ok, long term test and commission- RPCs Construction ing strategies not yet defined. The project is still in Production of preseries chambers has been halted a preparation phase and the largest technical con- due to concerns about trigger/chamber perfor- cerns are linked to the schedule for module con- mance and possible design changes. BaBar group struction - mainly on the procurement. The main has had some problems with new oiled chambers. financial concern is the uncertainty in the available After a visit of the factory several QA/QC changes funds for the Silicon Strip Tracker construction. were requested. INFN, under M. Calvetti, has set ECAL up a committee, with one person per experiment (BaBar, ATLAS, CMS,..) to liase with General Tech- Crystal Procurement: Tenders were opened on nica (the gap producer). A single QA/QC manual April 5. Financial organization of the contracts is on will be adopted with info from all experiments. the critical path. Mechanics and electronics order- Changes to manufacturing procedure are already ing are underway. The ECAL management should being implemented. CMS and BaBar will get prior- address modifications in production responsibili- ity for chamber manufacture during the summer – ties (linked to the crystal production) and in the around 10-15 chambers, part of them oiled, will be electronics coordination (P. Denes has moved to produced for CMS. Results from these chambers LBL). will be used to make the decision about oiling or CPT not. Originally decision date was June CMS Week. Working on V31 milestones. Physics TDR dates still Unfortunately this may slip to the end of this year. to be finalized. Installation window for online farm The impact on installation schedule is being stud- is worrying, reduced time to install equals more ied. money for manpower. CPT week was a success, but Muons-DT week layout will need to be revisited. Everyone A Manufacturing Progress Review (MPR) for MB requests that overlap of CPT and any detector week (DT chambers) is planned for 2-3 July. Follow up does not happen again. MPR's should be generalized to other sub-detectors Magnet, Infrastructure and electronics mass-productions. The milestones of the magnet have not been modi- Strips: The plate production continues at Torino. fied apart from the test that has been delayed by 2 There are problems with plate quality and packag- months in v31 to give more time to the coil assem- ing. bly. The manufacture of conductor and the start of Cathodes: There was a long delay of startup at Pro- the winding operation are 5 month late. However tvino. Industrial solutions have been investigated we consider that the time spent to get a conductor as backup. This is possible, but would cost more. A of good geometry and good homogeneity will detailed plan was agreed with Protvino to improve allow the winding operation to be done faster and the situation with a final decision beginning of July. thus the milestone for having the five coil modules on site has not been changed. DTs: Madrid has produced two chambers, the tests are restricted due to limited supply of FE electron- This year we expect to award contracts for: thermal ics. Legnaro+Aachen should have three superlay- shields, power supply, breakers, dump resistors, ers by 1st June. and at the beginning of next year the last contracts for the construction proper: inner cryogenics, heavy lifting. There is no float in magnet schedule

CMS Bulletin 01-02 for surface operations and main concern is the All subsystems were reviewed. Web and Paper Ver- schedule: tight schedule for conductor manufactur- sions will be available soon. Only issues of concern ing, tight schedule for winding & impregnation, are picked here: tight schedule for coil assembly. Tracker: Concern in Pixel Systems Synchronization Services with CMS DAQ. Recommend Integration of the Tracker and Pixel Projects Services of sub-detectors are shared between the Infrastructure Project and the corresponding sub- ECAL: FPPA – noise is high, still not understood, detector. CMS has to prepare for the installation of Intersil expert and JP Walder looking into problem. sub-detector infrastructure through industrial con- Optical Links, < 1 FTE, Much engineering to do - tracts. At beginning 2002 we should have contracts Consider building on Tracker link experience and effective for: Gas piping for MUON(Endcaps & technology. Consider operating links at 1.6 Gbits/ Barrel), Water piping for MUON (Endcaps & Bar- sec to reduce number of links. rel), Water piping for ECAL & HCAL, Fluorocar- Preshower - Pace chip, in DMILL - yield? impact of bon piping for TRACKER & SE. Piping activity on increasing memory to 190 cells. Cost and delay the yoke is in sub-detector's scope and the corre- associated with move to 0.25 micron technology? sponding money has to be foreseen in the 2002 Muons-CSCs: Radiation hard low voltage regula- budget of each sub-detector. tors, Study AC-DC conversion on magnet. The cabling over the yoke is tedious and has to be Muons-DTs: TRACO Chip - Will ATMEL version done with precision. We are exploring the possibil- work? Know in September. Use of AC-DC convert- ity of having a team of professional from Russian ers. Laboratories (they have done HERA B for example). DAQ/Trigger: Planning Well Advanced. Recom- mend a Common approach to Distributed CPUs. PMs are requested to discuss the cost and funding Muon Trigger: RPC PAC Chip in 0.25 micron tech- of such contracts in their Sub-detector Institution nology – noise v/s trigger rate. Installation and Boards. commissioning very difficult in time available. CMS Electronics Week Thorough test of complete system on surface is A CMS Electronics Week has been organized for essential the Week 14 - 18 May. The objective is to prepare Conclusions: CMS has a number of short term prob- the Sub-Detectors for an ESR, Review all the CMS lems. Most Sub-Detectors will have ESRs in 2002. Electronics together, Identify problems and possi- All Sub-Detectors have small, high quality teams. ble solutions, help in the planning process and All Sub-Detectors are short of enough good people Identify potential show stoppers. Members of the for testing, installation and commissioning. Tender- Electronics System Steering Committee (ESSC) will ing takes time, contingency, major risk is shortage act as the Review Committee and will prepare a of very good people. Therefore, share ideas, tech- report. Nine Technical (virtual) working groups on nologies, optimize organization. Review optical electronics have been created with the following links & LV Power systems in autumn with a view coordinators: of possible savings. 1. Grounding Shielding: F. Szoncso, F. Arteche LHC Symposium in Sardinia (25-27 Oct) 2. Radiation effects: M. Huhtinen, F. Faccio Web page (including programme) can be consulted 3. Power Supplies, through CMS homepage. We have to find 6 CMS Regulation Distribution: C. Rivetta speakers. PRS and Sub-detector PMs should sug- 4. Integration Issues gest names for speakers to the Conference commit- (Racks, cables,...): R. Pintus tee. 5. Controls (DCS, DSS): W. Funk 6. Quality and Project Costs reduction and Staging Scenarios for Aug 06 Management: St. Quinton, P. Cannarsa Physics Run 7. System Design: S. Marchioro In SC34 there was a first brainstorming discussion 8. Trigger: J. Varela on possible costs savings and staging scenarios. 9. DAQ: W. Haynes This is requested for the presentation in the Octo- ber RRB. The discussion will continue during the These groups have responsibility for developping a CMS week in Catania. CMS Electronics Policy and ensuring that a consistent approach is taken by each Sub-detector. Each submitted by M. Della Negra sub-detector should identify a contact person for each subject. The groups are virtual in the sense that they may mostly work without formal meetings.

CMS Bulletin 01-02

LARGEST SINGLE ELEMENT OF CMS ARRIVED AT POINT 5

Monday, May 21, 2001, was again one of those extraordinary days for CMS. It was the last stage of the special transport of the inner cylinder of the vacuum tank, which will house the supercon- ducting coil of the CMS magnet. The convoy left the premises of the manufacturer (Franc-Comp- toise Industrie in Lons-Le-Sau- nier) ﬁve days earlier under police escort. FCI is about 120 km from Geneva and the normal driving time is about two hours but not for this gigantic object.

The cylinder has a diameter of 6 meters and a length of 13 meters. It is fabricated out of stainless steel and the walls are 60 millimeters thick. The total weight is nearly 120 tonnes. This huge element is not only integral part of the vacuum tank, but also supports all the inner detectors. On its way to the CMS experimental area the colos- sal piece had to pass over the Jura mountains. The most exciting part was, of course, the last few hours, ﬁrst climbing up to the Col de la Faucille to an altitude of 1323 meters and then descending the winding road down to Gex and on to Cessy. The whole operation was well prepared and, with the exception of a few tree branches, nothing had to be removed to clear the path for this spectacular transport. submitted by H. Rykaczewski

CMS Bulletin 01-02

NA48 PINS DOWN DIRECT CP VIOLATION

On May 10, 2001 the CERN NA48 Collaboration the same detector, most of the systematic errors announced a definitive measurement of Direct CP cancel in the double ratio, opening the possibility to violation in the decay of neutral kaons into two perform a precise measurement. This is exactly the pions. The relevant parameter, called ε’/ε, was strategy followed by the NA48 experiment. -4 measured to be (15 • 3 ± 2.6) • 10 , about six stan- NA48 employs protons of 450 GeV/c momentum dard deviations from zero. from the CERN-SPS accelerator. An intense neutral This announcement culminates from a chapter of beam travels 120 m before entering the decay particle physics that began more than 15 years ago, region. By then the KS component has decayed, when a first round of experiments set out to mea- therefore the two pion final state, reconstructed in sure Direct CP violation at CERN (NA31) and Fer- the detectors, comes purely from KL particles. To milab (E731). NA31 reported evidence for Direct make KS, NA48 employs a tiny fraction of the pro- CP violation, while the E731 result was compatible tons which did not interact in the upstream target. with no effect. A new generation of experiments, These protons are passed through a tagging KTEV at Fermilab and NA48 at CERN improved counter and strike a second target placed just 6 m the technique of the predecessors and published upstream of the beginning of the decay region. For their first results based on a fraction of the statistics a 100 GeV KS, the mean free path before decay is in 1999. about 5 m, therefore a large fraction of KS survive CP stands for the combined operation of Charge to enter the decay region. Since the branching frac- Conjugation (C) and Parity (P). The C operator tion for KS to two pions is of order 1, most decays exchanges particles with anti-particles and P from the short beam originate from KS particles. By changes the sign of the spatial co-ordinates. While tagging the protons upstream of the downstream both C and P are maximally violated in the nuclear target, and making a time coincidence with the weak interactions, the violation of the combined CP kaon reconstructed in the main detectors, NA48 symmetry is more elusive. CP violation was first distinguishes a KS from a KL decay. observed in the decay of the long-lived neutral NA48 employs a magnet spectrometer with four π+π− π+π− kaon (KL) into by the Nobel-prize winning large drift chambers to reconstruct decays and experiment of Christianson, Cronin, Fitch and a liquid krypton calorimeter with tower structure Turlay, in 1964 at the Brookheaven National Labo- read-out is used as a photon detector. It provides a ratory. During many years following the discovery, selective first and second level trigger for the neu- π0 π0 beautiful observations of CP violation were tral decays. In addition, it reconstructs KL to reported, but all were confined to the KL particle decays with a signal to background ratio of the and all could be explained by a single small num- order 1000. To put this number in the right perspec- ber ε (just a few parts per mille in magnitude). tive, one notices that the CP violating π0 π0 decays π0 In 1973 Kobayashi and Maskawa realized that in from KL are 250 times less frequent than the 3 order to accommodate CP violation in the theory of decays, which can mimic the signal if two photons the weak interaction, at least six quarks subdivided are lost. Last but not least, the calorimeter must be into three families were needed. It is noteworthy calibrated to a few parts in 10000 to allow the cor- that at the time only three quarks were known rect matching of the momentum scale between neu- experimentally! tral and charged decays. If CP violation is part of the weak interactions, it To take into account the naturally very different should manifest itself not only in virtual processes vertex decay distributions for KL and KS – the ratio like the mixing of neutral particles, but also in the of the lifetimes is about 600 – without applying decay of quarks. CP violation in a decay process is large acceptance corrections, the experiment has dubbed Direct CP violation. decided to analyze the data assigning a statistical weight to the KL events proportional to the ratio of The parameter which describes Direct CP violation the K and K proper time distribution. The price ε . S L in the decay of the KL is called ' This parameter is to be paid for this weighting is an increase of the too small to be measured directly, but Nature pro- statistical error of about 30%, but the reward is vides access to a quantity which is six times larger important: the acceptance correction is reduced to a ε /ε. Τ ’ his quantity is the deviation from unity of the few per mille. double ratio of partial decay widths of K and K − L S into π0 π0 and π+π final states. NA48 has collected more than three and a half million K to π0 π0 decays, the statistically limiting π+π− π0 π0 L If KL /KS and/or / are collected from the mode. Data taking took place in 1997, 1998 and same beam, the kaon fluxes cancel in the double 1999. The announced result includes all the avail- ratio. In addition, if all four modes are collected able statistics collected so far. simultaneously, from the same decay region and in

9 CMS Bulletin 01-02

A new measurement from KTEV has been The NA48 physics program will continue after the ε ε announced recently and found to agree with the ’/ era. An exploratory search of rare KS decays NA48 result within 1.5 standard deviations. KLOE has been approved for 2002. A search for Direct CP at the Frascati ϕ factory, addresses the measure- violation in charged kaon decays employing simul- − ment of ε’/ε with a very different technique. taneous K+/K beams has also been approved. submitted by Augusto Ceccucci

10 CMS Bulletin 01-02

CERN RELAY RACE

On 23 rd May CERN held its 31 st annual relay race around the Meyrin site. Under excellent weather conditions CMS partici- pated this year with two senior teams : TRI- DAS "Pierrardins une fois" (L. Demeur, M. Brugger, L. Pollet, J. Ero, D. Gigi, A. Racz) and tracker engineering "Horst's Team" (M. Mermoud, D. Zurcher, P. Petagna, H. Breuker, F. Arteche, S. Kap- pler); both teams ﬁnished in ﬁne times, Horst's Team improving the CMS record time thus representing the fastest team from all LHC experiments. Next year we hope to have a larger CMS participation - so start preparing now !

11 CMS Bulletin 01-02 SSuummmmaarryy ooff tthhee CCMMSS WWeeeekk 55 -- 99 MMaarrcchh 22000011

JOINT SESSION OF FINANCE BOARD, A dedicated shielding has to be placed around the CMS MANAGEMENT BOARD, AND inner radius of the ME chambers. It was agreed that CMS COLLABORATION BOARD this shield is part of Infrastructure and is therefore CERN responsibility. The FB met on 7 March Two industrial services contracts have to be opera- News tional early 2002 for on-site pipework for gas and The Amendment #1 to the CMS MoU for the All- water (Muons), water (ECAL and HCAL) and fluo- Silicon Tracker has so far been signed by 19 out of rocarbon (Tracker). The respective sub-detector 31 Funding Agencies. communities should make sure that their 2002 bud- F. Triantis takes over from A. Vayaki as CMS Link- gets include their appropriate share of the costs of person to Greece. these contracts. A similar plan should be prepared for the cabling work, which should be carried out Maintenance and Operations by professional teams hired under a single contract. The RRB Chairperson has now sufficient input to The MB met on 8 March address M&O matters at the next RRB. All CMS Subdetectors Institutions should prepare an esti- News mate of their Type B costs (costs to be borne directly A CMS workshop will be held in Tehran at the end by an institute/group of institutes to maintain and of May. operate their equipment). The respective Sub- Contingency Plan detector FB’s should work out their potential shar- ing for Type B costs for common equipment. All The CMS Contingency Plan needs to be updated Linkpersons should discuss such costs with their for discussions in the forthcoming LHCC (March) Funding Agencies. and RRB (April). Decision for some critical items in Shortfalls and Contingency Plans 2001 is required. The plan needs to be approved by all CMS boards (FB, MB and CB). See CB summary The CMS Contingency Plan needs to be updated for the finally approved plan. for discussions in the forthcoming LHCC (March) The MB requested that Roger Cashmore be invited and RRB (April). Decision for some critical items in to the MB meeting (April 10) to get his opinions 2001 is required. The plan needs to be approved by firsthand on the CMS Contingency Plan in view of all CMS boards (FB, MB and CB). See CB summary preparation for the April RRB. for the finally approved plan. Common Project Contributions: Iran and Taipei-NSC CPT Organisation The FB (and later the MB) endorsed the proposal The MB recommended approval by the CB of the that a pair of HF support tables (value ~ 300 kUSD) new CPT organisation (See CB Summary). be considered as Iran’s Common Project contribu- Technical Co-ordination tion. The MB took note on the work and resources Taipei-NSC is likely to sign the MoU before the required for gas and liquid piping and cabling. It is RRB. The FB endorsed that Taipei-NSC might pro- proposed to appoint a “Czar” for cabling. vide opto-hybrids for the Tracker as an in-kind con- The Management Board recommended approval of tribution to be valued as Taipei-NSC’s Common an updated parameter drawing, mainly concerning Project contribution. RPC layout and the beampipe design; approval of Magnet Procurements, Infrastructure and Installation the v31 planning concept accounting for the addi- The inner cryogenics and phase separator will soon tional 4 month delay in the civil engineering for the be procured and considerable progress has been CMS cavern; approval of the design for the EE and made for all phases of the conductor production. HE/HF in the region of eta = 3, subject to an action All magnet supports (Pakistan, China-CAS) are at list; and to take note of PRR approval of HCAL CERN, first endcaps have left Japan and assembly RBX manufacture. will soon begin. Work on the optimisation of the pixels layout will be launched soon with the aim of having a workshop in autumn 01.

12 CMS Bulletin 01-02

The CB met on 9 March clearer. However, the situation could make this nec- Matters arising essary in 2002. The RRB has asked to be given the global view - the scope of the Computing MoU, the The discussions with Iran concerning the prospec- M & O MoU and the overall shortage of funds to tive membership of CMS of the Institute for Studies complete the detector. in Theoretical Physics and Mathematics (IPM - Teheran) have been concluded successfully and it is There are five items requiring urgent action to expected that they will make a presentation in the cover shortfalls. A plan to cover these items had June CMS week. For M&O the sub-detector been approved by the Finance and Management resource managers are urged to prepare their pro- Boards. This included borrowing from the Com- posals for Category-B costs (to be borne by the mon Fund (for YE4 and procurement of bakelite, respective sub-detectors) as soon as possible. ASICS and kapton cables for all forward RPCs (RE1-4)), borrowing within Russia (forward cylin- Retroactivity of the CMS Thesis Award. drical shielding and HF absorber wedges) and to Only theses submitted between July 1st of the pre- use RDMS manpower at CERN (to compensate for vious year and June 30th of the Award year can be ME1/1 cables and connectors). This plan was considered. An updated proposal for the detailed endorsed by the Collaboration Board. operation of the Award scheme may be found at: CPT Organisation http://unlhep2.unl.edu/~GSNOW/ The goal is to evolve the current organisation to cms_thesis_march01.ppt build a complete and consistent software system. The Collaboration Board approved these proposals. CPT consists of three projects (CCS – Core Comput- The announcement of the 2001 Thesis Award ing and Software, PRS - Physics Reconstruction and guidelines and nomination deadline will be posted Selection, and Software and Computing aspects of on the CMS Web site shortly. TriDAS). The CCS organisation was presented and New Collaborators an Institution Board needs to be set up; this will take time and it was requested that the previous The application for full membership of CMS by UC Software and Computing Board be allowed to con- Santa Barbara was presented by Joe Incandela, who tinue in this role ad-interim. The PRS is a new was previously working in CMS at Fermilab, and project led by Paris Sphicas, and because this cov- who will continue as leader of the US CMS Tracker ers all CMS, the CMS Collaboration Board is the Outer Barrel silicon group. UCSB already has an PRS Institution Board. TriDAS is similar to the pre- experienced silicon group and it is intended to vious project except that the High Level Trigger strengthen it further, with an appropriate level of software has been transferred to PRS. There are support. A production line will be opened to currently three cross-project groups and tasks increase capacity in the USA. This application will which are discussed by a Joint Technical Board to be voted-upon at the next Collaboration Board achieve consensus, but the decisions are made by meeting the three Project Managers. There are two CPT The application for associate membership by the weeks per year and activities during the CMS Beijing Glass Research Institute was presented by weeks are also to be organised. A Technical Note Yuncheng Ge. They have facilities for research on, detailing the CPT Task breakdown is in prepara- production and characterisation of crystals and tion. Collaboration Board should be informed of long experience of collaboration with particle phys- significant changes in the organisation of CCS and ics research institutes, and also with CMS. They are TriDAS. The Collaboration Board approved the continuing the R & D on CMS ECAL end-cap crys- proposal. tals and expect to produce them for CMS. The pro- LHC Computing Review and first ideas on the Comput- duction capacity can be increased if financial ing IMOU resources are found. This application will also be voted-upon at the next Collaboration Board meet- The LHC Computing Review ("Hoffmann ing. Review”) is published. The initial LHC systems will be purchased in 2005 - 07, with prototype sys- Contingency Plan tems being built in 2002 - 04. The prototypes need Our goal remains to have as complete a detector as money and the CMS Core Software needs man- possible for the first physics run in August 2006. power, which is a major reason for an IMoU. The Overall we have a modest funding shortfall but aim is to make an initial presentation at the April some big contracts, for crystals and for the tracker, 2001 RRB and to present the IMoU in October 2001. are still to be negotiated. The strategy being fol- Core Software has a shortage of manpower, which lowed, proposed by the CERN Director for it is hoped to cover with 'level of effort' commit- Research, is to keep the RRB informed of shortfalls ments with individual agencies or institutes. Effort as they emerge, but not to request any extra fund- should be made to mobilise GRID resources for ing until later when the overall picture will be CMS.

13 CMS Bulletin 01-02

CMS week outside CERN in 2002 – 2 months of UX operations (EB+ mechanical installation) are moved to SX, after completion The CMS management strongly recommended that of the magnet test. (In case of any further short- there be no CMS Week outside CERN in 2002. This ening of the underground window, more activi- is partly because there is expected to be an LHC ties will be moved.) Symposium in the USA but more because these weeks are very important for information exchange – pre-installation of CMS infrastructure in the and one week is already largely taken over by the experimental and service caverns is started dur- LHCC Annual Review. The Collaboration Board ing the last 4 months of the Civil Engineering accepted this proposal for 2002. It was suggested window. that institutes wishing to raise the profile of their – the second electromagnetic endcap is installed CMS activities could offer to host sub-detector after the pilot run. weeks. – the beampipe installation is started in parallel Technical Coordination with the end of tracker commissioning. – activity on the + end of the detector is factorised The Collaboration Board approved the MB recom- as much as possible from that on the -z end, so mendations on technical matters. that cabling of the +z end can proceed whilst the Report from the Conference Committee -z end is still being installed in UX. The updated list of past and future conferences and It is clear that shrinkage of the underground win- proposed speakers can be found at the usual web dow will eventually lead to cabling and commis- page: sioning activities, rather than mechanical assembly, becoming the critical path to an operational CMS. cmsdoc.cern.ch/~wulz/conferences/hand- out.html. Milestones must be re-baselined to v31 by end of June 2001. Special meetings will be held at the June It is also accessible via the CMSDOC home page. collaboration meeting. With the encouragement of The Board was reminded that it is the responsibility the LHCC referees, Level 2 “ready for installation” of the Institute representatives to propose speakers. milestones are being introduced to de-couple the submitted by M. Della Negra pre-assembly of major items from their use in the master assembly sequence. Milestone reporting to TECHNICAL COORDINATION, LHCC will now be done quarterly. SCHEDULE AND INTEGRATION Assembly and Integration v 31 planning Construction of the North beam hall annex, build- Faced with significant changes in the expected ing 947, for ECAL active storage, has been delivery dates of the underground areas from civil approved and is due to start in summer 2001. engineering, CMS master planning has been Trigger vulnerability to RPC noise, investigated in updated to version 31. a recent workshop, led to the conclusion that CMS The experimental and service caverns are now should try to build reasonably low noise RPC’s, scheduled to be delivered on 1’st April 2004 (cf 1 should improve the front-end trigger processing Dec 2003 previously), allowing underground technology and algorithms to give better noise installation to start on 1’st Sept 2004 (cf 1’st May immunity, and should modify the RPC layout to 2004). The date LHC is closed to allow (single) improve acceptance and redundancy. beam to circulate is unchanged sincev30 at 1 Feb The proposal under study for the barrel is to incor- 2006. A 1-month pilot run starts on 1 Apr 2006, fol- porate the first RPC layers with the tail catcher in lowed by a 3 month shutdown. Thereafter (from 1 wheels -2,-1,1,2 and in wheel 0 to move the first Aug 2006) a 7 months physics run is foreseen to RPC layer to the coil side of the tail catcher -1 deliver 10b fb . CMS v31 planning must therefore absorber. By removing conflicts with cables, this deal with an underground installation window would allow a small increase in active area of the reduced by 4 months, whilst the surface assembly layer 1 RPC’s, to improve φ/z coverage. window is 4 months longer. In the endcap, the sensitivity to high rate is likely to This is achieved by 6 principal changes. become an issue due to background at high lumi- – surface installation windows are lengthened for nosity. In this case the proposal being studied is to projects with little float, by delaying the install an additional layer of RPCs in station 2, for start of the magnet test by 2 months. (helps HF and which the separation between the YE1 and YE2 Muon system +z). disks would have to be increased by at least 30mm. – pre-cabling and commissioning are carried out A new beampipe, under study for some time, will on the surface where possible (this will need become the baseline for presentation to EDR pro- extra equipment and resources will be needed viding prototype tests are successful. The pipe has on the surface). a 4 m long Be central section braised directly to

14 CMS Bulletin 01-02 stainless steel cones. Low profile vacuum flanges the digging operation has been difficult and has join the central section to the outer parts and the shown the poor quality of the molasse. Civil engi- flanges and bellows are mounted on a conical sec- neering works are considered to be 9 months late tion (no cylindrical step). The pipe support and and this has been integrated into the CMS schedule shape near 15m have been modified to allow 10mm v31 that has been adopted as the new baseline for opening without pipe removal. NEG pumping can CMS. On the surface, construction of the SUX5 be regenerated without removing the pixel system. (cooling + ventilation) and SG5 (gas) buildings is The integration of the HCAL readout boxes (RBX) progressing well and will be handed over to CERN with surrounding cable ways, allowing for mainte- on 1 July. nance of the HCAL photo-detectors and electron- Assembly of the barrel yoke has continued in the ics, was the subject of a recent PRR. The key issues surface hall. This is an ETH-Zürich contract identified, and satisfactorily addressed, were reli- awarded to the consortium DWE/FCI. The first ability of the HPD and the difficulty of providing three barrel rings, including the central barrel ring, realistic maintenance access, particularly to the 73- have been finished, and the fourth one is being channel HPD reading out the first layer. The RBX assembled. The welding of the external vacuum was approved for manufacture. tank is in progress, and it will soon appear as an integral shell. After machining of the inner rails the Physics-engineering task forces inner vacuum tank has been completed at Lons le The task-force studying integration along the η = 3 Saunier in France. It will be delivered in May to EE/SE inner boundary has reached a conclusion Point 5. All support feet will be modified to allow and the geometry is now well enough determined crossing of manifolds and cabling. to un-block the final design of EE and SE. Crucial After manufacture at HHM in China all endcap information came from recalculation of the doses carts have been received at CERN. They have been expected along the inner edge of the HE scintillator equipped with ancillaries. The Endcap disks are in layers, using latest HE and beampipe geometry production at Kawasaki Heavy Industries in Japan, and materials. The crystal coverage between 2.9 under contract from University of Wisconsin. The and 3.0 was shown to have a small effect on doses three disks for the first Endcap have been received in HE (electromagnetic leakage) and it has been at Point 5 in April. Assembly of the first endcap agreed that it is sufficient to modify EE inner crys- disks on the carts will start beginning of May. The tal shapes to produce a near octagonal inner geom- disks for the second Endcap are expected to be η ≈ etry with 3 as an inscribed circle. Much larger delivered in September. effects (factor 4 in dose compared with TDR expectations), due to the geometry differences, affect the Ansaldo has subcontracted the manufacture of the first 6 layers of HE and changes to the longitudinal winding line to TPA in Italy. Most components are and transverse segmentation and readout of HE are available and first tests are being performed using being studied to counteract this. dummy conductor. The mandrels will be made using seamless rings for the flange region. The two The tracker material budget and its effect on ECAL first rings have just been produced by Dembier- is the subject of another task-force. mont in France. The manufacture of the mandrels, The tracker bulkhead and connector layouts are not subcontracted to San Giorgio Siegen in Italy, is suf- yet complete and no detailed geometry files yet fering some difficulties in the procurement of alu- exist, although the average material contained in minium alloy plates due to the booming jet CMSIM121 looks realistic. CMSIM 121 has been industry. These aluminium plates will be made by used to check the effect on benchmark processes Pechiney in France. whilst specific studies of electron and photon The delivery of conductor components from con- reconstruction have shown that the effects of gran- tracts placed by Fermilab is progressing well. Outo- ularity in material density of the current designs, kumpu (Finland) has now delivered the third particularly due to connectors, can have a large article (320 km) of super-conducting strands. Deliv- effect. The main avenues for progress appear to be ery of the special first article (80 km) from IGC in choosing and orienting connectors, and possibly (USA) is done, completing the IGC supply. The in exporting more tracker connectors to the patch delivery of the pure aluminum from Sumitomo panels in the HE-coil gap. This work will be (Japan) is completed, and a reserve will be ordered. updated periodically as both engineering and sim- After improvement of the process to better the ulation progress. inter-billet-zone mechanical characteristics, Alu- submitted by A. Ball Suisse has started mass production, and twenty lengths have been produced. MAGNET / INSTALLATION The delivery of conductor components from contracts placed by ETH Zürich is also progressing The digging of the pillar between USC5 and UXC5 well. Five good cables have been produced at is finished and concreting has started. However, Brugg Kabelwerk, and the problems with the

15 CMS Bulletin 01-02 cabling machine seem to have been solved. Four ment, beam pipe and pixel groups, in order to opti- real inserts have been extruded at Cortaillod, and mize the integration of the various region of the the next extrusion is scheduled for June. The line tracker. for the EB welding operation is operative at Tech- The first step was the optimization of geometry and meta and has been extensively tested using full sec- integration of the bulkhead region. The group tion dummy conductor produced at Alu-Suisse. defined an upgraded version of this region and in The final commissioning of the EB welding line addition - addressing a requirement of the ECAL - using 3 components, the 5 km of dummy insert they studied a possible increase of the tracker cov- extruded at Cortaillod and the first lengths of rein- erage at large eta by equipping the tracker outer forcement material produced at Alu-Suisse is in end cap (TEC), where possible, with additional progress. modules. The KODEL contract for the manufacture of the Engineers responsible for the outer barrel (TOB) are swiveling platform by Hanjung is operative. The working together with the groups responsible for welding plan and the engineering report have been the inner subsystems (inner barrel –TIB- and inner accepted, and manufacture has started. disks –TID) to optimize the arrangement of the ser- The EDR for the power circuit has been success- vices running in the gap between TOB and TEC. fully helds. Procurement of circuit breakers, power This work is delicate, since the dimension of the supply, and dump resistor will proceed. gap is a crucial parameter of the tracker geometry. The manufacture of the external cryogenic ele- A first detailed design of this region is being pre- ments by Air Liquide is progressing well. The first pared, and will be verified and validated with the functional tests are expected to start in 2002 in the services mockup planned for this year. surface hall. A workshop for the inner cryogenics is The tracker is steadily moving towards the con- being scheduled in June in Saclay. struction phase, and the procurement of most items The design of the metallic structures surrounding is planned. In particular, the tendering of the TOB the yoke elements is finalized and the tender is mechanical structures is expected already for this being prepared. The first structure will be used as summer. Before placing the orders for the mechani- support for the functional tests of the external cryo- cal structures it is crucial to revise the details of the genics already in 2002 in the surface hall. At the tracker design in order to optimize the material same time the subdetector services will be laid budget. down on these metallic structures and thus the def- On this issue, three presentations were scheduled inition of these services is now on the critical path. in the general tracker meeting. Some key points of The first four jacks for the HF lifting system have the design of the main tracker subsystem (TIB+TID, been commissioned in the surface hall, using a 300 TOB and TEC) were analyzed in detail. tonne dummy load. More than 100 movements For the TIB and the TID, the services grouping have been performed representing five-year opera- scheme was reviewed. Power, signals and controls tion. are carried in and out via a kapton bus with copper submitted by A. Hervé lines; connections to the aluminum multiservice cables are made at the end of the TIB+TID volume. The cooling pipes are in aluminum; their grouping INNER TRACKING might still be optimized. During the March 2001 CMS week and the January In the TOB and the TEC, the larger dimensions 2001 tracker week the presentations addressed have suggested that G10 should be used instead of mainly the following topics: kapton for the bus carrying signals and control: – improvements to final design of the mechanical G10 is cheaper and technologically easier although system somewhat heavier. – progress in preparing all centers for the produc- The details of the design still need to be optimized tion of a full set of 200 modules for ‘Milestone to minimize the total amount of material. The large 200 number of connections needed in the cooling pipe – progress on the FE electronics and hybrid system drives to the choice of copper-nickel as the including tests of the radiation hardness of the pipe material, since it allows easy soldering. The 0.25 µm electronics. groupings of the cooling pipes and their thickness have been optimized to minimize the material bud- Many steps forward were made also in the defini- get. The exact shape and dimensions of the alumi- tion of the pixel electronic and DAQ system. num elements providing the thermal contact At the opening plenary session A. Cattai presented between cooling pipes and sensor frames can still the current status of the tracker project. Soon after be optimized; this will be done on the basis of the the presentation of the EDR a working group was ongoing cooling tests. created with representatives of integration, align-

16 CMS Bulletin 01-02

The tracker community is getting ready for the pro- software tools are standardized, therefore the duction of the 200 milestone modules with final results stored into the DB will be homogeneous and dimensions and quasi-final materials and electron- compatible among the different centers. ics, according to the construction procedure. After During the ’Milestone 200 ’and the final production the assembly of the first modules a System Test will each part of the tracker (sensors, hybrids, modules, be performed using a significant number of these opto-electronic...) will be identified by a bar-code. modules to verify that the behavior of a single The results of each measurement performed on any module scales well in a complete system. This component and at any time along the production includes testing the electronic behavior of the FE chain will be stored into the DB. At any time, with a hybrids, of the control ring, of the low and high query to the DB, it is possible to make the inventory voltage power supplies and of the interaction of what is available in each production center and between mechanics and electronics. the status of each part of the tracker can be known In practice the System Test will start by reading out in real time. The general structure of the DB is com- a set of final modules with the front end and opto- pleted and is operational. electronics. It will continue with the integration of The Lyon group has developed a general interface the modules into the TOB mechanics and with the to the database addressing the requirements such studies of the influence of a realistic environment as: query, registration of components, shipping and on the module performance. These tests will start receiving, insertion of the data, etc. D. Contardo on May 2001.The results will be reported in an Elec- presented the general interface at the general tronic Systems Review (ESR) before the beginning tracker meeting and at the Thursday plenary ses- of the mass production of the final modules. sion. Specific applications for the sensor testing The sensor quality assurance centers are ready to have been written and are being tested. Other start testing sensors. The automatic programs that applications for assembling and module testing are control the instrumentation and analyze the data in progress. have been released. The automatic testing proce- The first prototype of the front-end hybrid of the dure is as follows: the Lab-View measurement pro- SST was delivered in December. The hybrid was gram read an input file in which the list of found to have a problem that was identified and a measurements, the measurement parameters and robust solution found. The new design was agreed the acceptance criteria are contained. The measure- upon in a formal meeting during the January ments of the leakage current, capacitance and resis- tracker week and the new hybrid has been in pro- tance start automatically. The analyzing programs duction since the 1st of March. A document compare the results with the acceptance criteria. describing this front-end hybrid and its technical The results will be automatically inserted into the specification is in preparation for the Market Sur- Tracker Database (DB). vey. The centers will start testing sensors as soon as they During the last four months more APV25 chips arrive. At the moment a calibration phase is in were individually tested. The measured yield was progress. The tested sensors will be assembled about 75%. M. Friedl presented the status of the automatically at Gantry centers. Two Gantries are radiation hardness tests of the final electronic chip now fully equipped and commissioned. They are at the general tracker meeting. Eight APV25S1 were ready for building the first TOB modules. After irradiated by Vienna and IC groups at PSI, with a being assembled at the Gantry centers the modules pion beam of 300MeV/c and a flux of 109cm-2s-1. will go to the bonding and testing centers. The The total fluence of irradiation was slightly below preparation of the bonding stations is proceeding 2 × 1014 pi/cm2. well. The most important effect of radiation on the FE With regard to the module testing, there are two electronics is single event upset (SEU) due to local different module test DAQ systems. The simpler charge deposition by highly ionizing particles (e.g. one is already operational in Aachen and will be a recoil nucleus). SEU produces both digital effects, used to investigate the functionality of the FE e.g. memory cell flips, and analogue effects, such as hybrid, to identify dead and noisy channels. It inte- parasitic charge on capacitors. Both of these effects grates a slow control system that is fully automatic. are not permanent and both were observed to occur The more complex one is operational in Lyon and with the APV25. CERN and is in evolution. It will be completed before the System Test starts. It will allow reading The main intent of the irradiation was to measure out the hybrid as planned in the final tracker sys- the total SEU cross section defined as the number of tem. It enables the control and test of several mod- SEU observed divided by the fluence. When the ules in parallel, has safety interlocks for currents, cross section is combined with CMS simulations, temperature, bias and low voltages. It includes a 100 digital SEU are expected in the tracker per hour system of adequate capacity and is fully automated of high luminosity running. These SEU can be and interfaced to the DB. The two set-ups and the cleared by a general reset at fixed intervals. The

17 CMS Bulletin 01-02 cross section is much lower than the one measured will also contain sensors of the full size. Submission in a previous irradiation with heavy ions (a factor is planned for April 2001. 8 of 10 ) since every heavy ion produces an SEU submitted by G. Rolandi when it hits a sensitive volume, while only few pions produce secondary particles that actually generate an SEU. The cross section for analogue ELECTROMAGNETIC CALORIMETER SEU is higher than for digital SEU but the expected (ECAL) rate is still very low in both the inner and outer bar- Crystals rel. Since the pipeline cells are constantly refreshed the analogue SEU effect is harmless. After irradia- Progress has been made to established the new tion a small decrease in the APV gain has been crystal production technology in Russia, involving observed, which affect the signal-to-noise. This the use of big ingots. This new technology will reduction can be compensated by appropriate nearly double the production capacity. This will adjustment of the bias settings. On the basis of allow us to reach the ECAL crystal production these, and previous results with heavy ions, the schedule. The first delivery of 100 crystals of pre- robustness of the front-end electronics in 0.25µm production in China is under evaluation in CERN technology has been confirmed, with no permanent and Rome. ETHZ has launched the tendering pro- damage being observed. cess for the remaining EB production (26000 crystals) and for the total EE production (16000 The pixel community presented their progress in crystals). Efforts have been made to improve the × many areas. The submission of the 36 40 pixel GIF setup to establish the UV excitation method; chip in DMILL technology from August 2000 has this is an important step in crystal production qual- been received and is now being tested. This chip ity control. (8.4 × 6.2 mm2) has the correct readout architecture but still includes a number of extra pins in order to Mechanics-EB perform additional diagnostics. The revised design of the modules have been tested The final Read Out Chip (ROC) with 52 × 53 pixels, and prototype (new grid produced in Italy), this allowing complete modules to be fabricated and design consists of grid made by 3 bolted pieces, tested, is currently being prepared and is likely to Alveola tied on their front face and requires small be submitted at the end of April 2001.This is a delay modification of the tablets. The long hole option of a few months compared to the original schedule. has been chosen and the cooling piping has been This chip will allow to perform complete system changed from aluminum to stainless steel. Front tests with the Token Bit Manager (TBM) chip that supermodule plate, which has to accommodate the will be included in the same engineering submis- monitoring and front cooling, is still under study sion. with simple webs. The ROC TBM interaction is now defined, includ- Monitoring ing the I2C protocol that allows to download all the All the light monitoring parts have been proto- pixel trims and DAC values of the ROC in the typed and assembly procedures have been tested whole pixel detector (45 million pixel channels) in using the old prototype basket. 0.3 s at the start of a run. The TBM chip is currently tested in a FPGA version together with the FEC EE-photodetectors that has also been fabricated in a first prototype The VPTs preproduction (500 pieces) has been version. A FED prototype unit for the pixel readout delivered in UK and is under evaluation, results exists now and is currently under test. seem promising. A change was made to the number of readout EE / SE fibres of the barrel pixel detector that allows a factor of 2 reduction in fibre-count, also reducing the After the EDR the main concerns are the Tracker material budget of the pixel system. Material Budget in front of ECAL specially in the Endcap region, the Tracker coverage at large rapid- A mini workshop with the aim of defining all miss- ity and the optimization of the η = 3 region which ing interdependencies of the pixel readout system has to be concluded. (ROC-TBM-FEC-FED) has been held at PSI just after the CMS-week. The sensors from the second APDs and VFE evaluation batch are currently under test and the For APDs the screening process is now establish first results indicate that operation of the irradiated using Cobalt irradiation. The production will start sensors at the planned 300V is possible. Prepara- soon in Hamamatsu. The problems with the elec- tions have started for the last evaluation batch that tronics encountered during the summer 2000 tests have been reproduced in laboratory and simulated, a new, more robust, layout of the VFE board has been defined.

18 CMS Bulletin 01-02

M0-Prime also made at Fermilab by US and RDMS personnel A system test is foreseen in summer-2001 mainly to in order to understand the read out box (RBX) lay- establish the H4 calibration procedure; monitoring, out of HE. It appears that the RDMS and US groups DAQ, Calibration constant extraction. have found a solution for the HE RBX. submitted by J.L. Faure During the CMS Week, the |η| ~ 3 region was examined intensively. The new evaluation of the radiation field was larger than had previously been HADRON CALORIMETER (HCAL) assumed. The HE group responded by using all The HCAL management and the Integration Group possible longitudinal segmentation and optimally scheduled a Procurement Readiness Review (PRR) deploying it. In addition, HE agreed to split the during mid-February, prior to the CMS Week. At smallest angle readout in the first few layers in issue was an evaluation of the HF preproduction depth where the electromagnetic energy deposit is prototype, PPP2. The result of the review was particularly intense. Finally, HE is studying the approval to go forward with full production of the possible use of potentially more radiation resistant HF wedges. However, there is a check point with plastics. In parallel, the EE group agreed to study the first final wedge. Meanwhile the Fermilab engi- cleaving crystals so as to give more extensive cov- neering team is preparing a full conceptual design erage of the exposed HE scintillator tiles. These of HF, detailed designs of the wedge structure and actions come at the last possible moment, as HE the assembly scenario of HF. The plan is to visit the optics is already in full production. production site in Chelyabinsk in May, followed by A PRR was held for the readout Boxes (RBX) just an Engineering Design Review (EDR) for the com- prior to the CMS Week. The result was an approval plete HF in July and then inspection of the first to go into production for HB and HE, the latter final wedge in September. In this way, HCAL can after a check point. In addition, there was an make maximum progress in production. improved set of parameters which evolved as a Also presented during these meetings were plans result of the review. First, the largest package – the for the HF quartz – plastic (QP) fibers and the pho- 73 channel HPD - was found to be shrinkable, miti- tomultipliers (PMT). Both were given the approval gating the access problem. Second, the technical to go forward. In the coming months these two risk of losing an entire 73 channel HPD was items will be bid and bought. Thus, plans are in reduced by allowing for recabling of the inputs of a place to carefully watch HF and advance the sched- 73 channel HPD to the 19 channel HPD, carrying ule, as it is on the critical path. the corresponding tower, so that the entire depth The Hungarian groups have agreed to take respon- would still be read out in the case of a failure of the sibility for stuffing the fibers for HF, primarily in 73 channel HDP. Clearly, there was a good synergy Budapest. Production absorber modules will be between the Integration group, the Tracker com- sent from Chelyabinsk to Budapest, fibers will be munity, the HCAL group, and the Review Commit- inserted, and shipped to CERN where PMT and tee. optics will be installed. However, for the first The HB and HO geographic sectors of HCAL are wedge, extensive acceptance tests will be per- already in full optics and absorber production. The formed at CERN which supports the argument that first half barrel of HB absorber and optics is deliv- the first experience on stuffing fibers should also be ered to CERN, with the second expected in the obtained at CERN. summer, about six months ahead of schedule. For HE the PPP2 was completed in Protvino and The critical path schedule for HCAL is currently QA/QC data are available for evaluation. HE the front end electronics, which still has slack time megatile production is now fully operating and is for another submission and for a commissioning 5% complete. The HE optics begins with scintillator and “burn in” period in SX5. This commissioning sent from CERN (purchased by U.S. groups) to period is considered to be important if repairs in Kharkov for machining. The scintillator is then sent UX5 are to be minimized. The performance of the to Protvino where it is assembled into megatiles ASIC submissions for the building blocks of the with the splicing and insertion of fibers and the chosen option have been on schedule and within assembly of the cover plates. The schedule calls for specification. The full submission of the crucial QIE delivery of the first half of HE, both absorber and ASIC was just made. The design has also been optics in the middle of 2001. There will be a visit by altered to use the CERN serializer which ECAL CMS and HCAL experts to Minsk (MZOR) in April have adopted. to inspect the first HE endcap absorber just prior to The next major purchase for HCAL is the hybrid shipment to CERN. photodiodes (HPD) for HB, HO, and HE. Placing of In addition, the crucial SE, EE, HE, ME1/1 area the HPD contract through CERN is underway. The requires a complete and detailed mockup. The HE delay in placing the order has to do with electrical groups and the integration group have jointly crosstalk, which appears to have now been solved begun work on this. A mockup of HE alone was by aluminizing the diode bias electrode. There

19 CMS Bulletin 01-02 remains an optical crosstalk which has been TRIGGER reduced to an acceptable level by overcoating with The CMS trigger group passed a major Level-1 π a wavelength anti-reflection dielectric layer. A milestone in March with the approval of the CMS program of improving the yield using this solution Trigger Technical Design Report (CERN/LHCC is now in place with the vendors, and first produc- 2000-38). The document may be found on the CMS tion HPD are expected in November, 2001. web pages for the LHCC, TDR documents: http:// The Physics Reconstruction and Selection group for cmsdoc.cern.ch/cms/TDR/TRIGGER-public/trig- jets and missing energy has been fully integrated ger.html into the HCAL organization. In addition, HCAL The CMS Trigger TDR not only represented the cul- has been reorganized to gather together slow con- mination of an extensive program of trigger design trols jobs which are needed for several tasks. At the and prototyping, but also a major effort to fully CMS Week, joint meetings between hardware simulate CMS physics through a model of the groups, slow controls groups, and PRS experts detector, electronics and trigger. This was done in were held. This re-organization of HCAL is crucial ORCA4, the CMS Object Oriented Reconstruction as we move towards installation, calibration, and for CMS Analysis, which takes hits from the com- commissioning of the HCAL. The revised organiza- plete GEANT detector modeling, creates digital tion chart for HCAL was shown as proposed by the signals as delivered by front-end electronics and Project Manager which incorporates the PRS group performs bit-level integer simulation of the trigger completely into HCAL and combines several hard- function. ware and software efforts. It was presented at the HCAL IB and approved. The calculated trigger rates showed that even with a safety factor of 3 reduction in the CMS initial data submitted by D. Green acquisition readout capacity of 75 kHz to 25 kHz, the Level-1 trigger could capture the events needed MUON DETECTOR for the CMS physics program with high efficiency. In the Barrel DT meeting the usual review was The CMS trigger group also reported on other sig- made of the status of sites in view of mass produc- nificant progress following the submission of the tion and of the crucial Milestone at the end of May TDR. of 1 chamber assembled per site. The hot point was The Warsaw group reported the latest test results a proposal to prepare the plates and the beams at on the second generation Pattern ASIC RPC trigger CERN. This subject was then re-discussed with the chip manufactured in 0.35 micron AMS technology. CMS Management in the restricted DT Committee. While the ASIC has some minor errors, the basic The conclusion was that the most critical item is the pattern logic performs satisfactorily and the chip is I-Beam production in Protvino, and that the pro- usable for testing with the detector. duction of plates should be done in Dubna as planned. Urgent actions were agreed to assess the There have been studies of RPC performance and feasibility of I-beam preparation in Protvino. A the effect of surface treatments in reducing noise. final decision will be taken as soon as possible, at There are ongoing studies by the Warsaw group the latest in the next MU Week. using a full ORCA simulation in order to check, whether modifications to the RPC trigger could Also discussed were the plans for the chamber tests help with noise rates in excess of the original trig- at the Storage area in the ISR. A final proposal is ger design value of 10 Hz/cm2. The Helsinki group due in the next MU Week of April. The main prob- reported on design of new optical link and splitter lem in the Barrel region is the RPC trigger rate with boards for the RPC signals. the current Trigger design for the expected RPC chamber noise of about 30 to 40Hz/cm2. The Padova group has tested the first generation Drift Tube trigger Bunch and Track Identifier (BTI) In the forwarded region the design of the RE1/2 chip on a full size chamber and new tests are being station is still incompatible with having overlap- done with the final front-end electronics. The ping chambers and the number of RPC planes migration of the chip from ES2 to ATMEL 0.5- (four) is judged to be risky at High Luminosity. Dif- micron technology is complete and 5 of the new ferent scenarios were discussed. prototype chips are expected in September. Several It is expected that these problems will be examined prototype multi-chip BTI modules have been in the CMS SCs of May in order to make a final rec- tested. The first prototype (ES2) Track Correlator ommendation or decision in the next CMS MB in chip (TRACO) did not have full functionality due Catania. One of the risks is that a redesign of part of to a manufacturing error and a revised design will the inner barrel RPC station will generate delays in be submitted in the ATMEL process soon. The pro- the production and installation schedule. totype θ-trigger, φ-trigger, and control boards have submitted by F. Gasparini been tested and irradiated. The Bologna group has tested and irradiated the first prototype drift tube trigger Track Sorter Slave

20 CMS Bulletin 01-02

(TSS) and the final device is in layout. The Track The Bristol group has taken delivery of a generic Sorter Master (TSM) is being developed using 48k test module for the Global Calorimeter Trigger gate pASICs. The prototype Trigger Server board (GCT). The module consists of a joint CMS/ATLAS has been tested and irradiated. project motherboard with Channel-Links and Vir- The Vienna group has made extensive comparisons tex Field Programmable Gate Arrays (FPGAs) for between the Drift Tube Track-Finder VHDL code the CMS GCT function. The GCT algorithm testing and the ORCA4 simulation. Logic has been devel- will be done using this module. oped for extrapolating between MB2 and MB1. The Vienna group has finished the fixed VHDL Link technology evaluation has resulted in the code for the prototype Global Trigger Logic Board choice of parallel LVDS. FPGAs have been evalu- with predefined templates, condition types and IO. ated on a test board. They have prepared setup and placement software The Rice, UCLA and Florida groups have evalu- that delivers flexible VHDL code for connection of ated the results from the successful system test of input channels and algorithm bits to output pins, the CSC Endcap Muon Trigger Muon Port Card, definition and placement of conditions, and defini- Sector Receiver Card, Sector Processor Card, back- tion of algorithm logic. The goal is to create auto- plane and Clock and Control Board. While the mated chip design. design has been proven to be conceptually sound, submitted by W. Smith there is a need to reduce latency. This could be achieved through integration of the Sector Receiver DAQ and Sector Processor Cards. This would reduce the Endcap Muon Track Finder to a single crate. This PVSS conquers CERN requires a new backplane technology, higher band- Following the decision of the four LHC experi- width optical links and the combination of the ments to use a common SCADA product for the function of several separate FPGAs into a single detector supervision, PVSS II from ETM was cho- higher density FPGA. Each of these aspects is sen last year. Since then this SCADA toolkit has under prototyping. conquered CERN. More and more services, apart The Vienna group has developed a simulation of from the LHC experiments, have already started to the Global Muon Trigger in ORCA4 that works examine a possible use of PVSS to control their sys- with the latest CMS geometry and a 3D magnetic tems. This will offer easy integration and intercom- field. This has been used to improve the design of munication between diverse systems. Furthermore, the GMT charge assignment and application of the in March of this year PVSS II became the officially calorimeter minimum ionizing and quiet bits. recommended SCADA product at CERN. To ease For the ECAL Upper Level Readout and Trigger the utilization of PVSS II for our purposes even fur- board, ROSE100, a single FPGA will contain code ther, a framework is being provided which offers written for the Trigger Primitive Generation (TPG) dedicated configuration tools for the most common by the Palaiseau group and for the readout path by equipment e.g. CAEN power supplies. The func- the CERN group. Testing of the new boards is tionality provided by PVSS II is constantly evolv- expected by the end of the year with trigger inte- ing. For instance, the latest version, 2.11.1, contains gration tests to follow. the first release of a PVSS web server. ETM's future plans for remote control are to offer a web based The Wisconsin group has completed a second-gen- remote installation of a thin client for Windows and eration prototype Regional Calorimeter Trigger LINUX. This thin client will offer the same 'look (RCT) backplane that incorporates the algorithm and feel' and security as the local user interface. changes described in the Trigger TDR. The new Clock and Control Card prototype design is com- Many CMS subdetectors are currently starting to plete. Designs of the second-generation prototype use PVSS II. The main usage at present is the proto- Receiver and Electron Isolation Cards are under- type testing, control of test beam installation and way. A new Serial Link and Test Card are being quality checking during the assembly. For instance, designed based on the new Vitesse 4 x 1 Gbit/s low voltage system test of ECAL, radioactive interconnect chip. Documents specifying the inter- source control of HCAL, tracker front-end configu- faces between the RCT and the E/HCAL TPG and ration and so on. Actually there are 142 registered the Global Calorimeter Trigger exist in draft form. PVSS II users at CERN of which 9 named CMS as The RCT simulation code has been updated. The their primary project. Wisconsin group will be using the Wisconsin Con- submitted by F. Glege dor system to gain access for Monte Carlo generation to more than 600 CPUs. The data will be SOFTWARE processed in collaboration with the Fermilab group. Fast Simulation A topical meeting on fast simulation in CMS was held at CERN on April 10. The presentations cov-

21 CMS Bulletin 01-02 ered requirements for physics studies, examples of are ghost volumes and the so-called event biasing. existing programs, and ideas on methods to speed The latter allows to simulate first a predefined up simulation. region or part of the event, after which it can be The basis for simulation in CMS is a detailed decided to continue or drop the event, e.g. depend- GEANT based simulation program, presently ing on the trigger result. CMSIM, using GEANT3, which will be at an appro- Detailed tracking and calorimetry have different priate time replaced by OSCAR, using GEANT4. time consuming features. Although the tracking of These programs contain detailed geometry descrip- the particles in a tracker is subject to a lot of details tions of the detector, and sophisticated tracking and (inhomogeneous magnetic field, multiple scatter- showering methods, unavoidably associated with ing, bremsstrahlung, secondary interactions, etc.) considerable CPU consumption penalties. Fast sim- most of the time is taken to be spent in digitization ulation can be realised by using simpler geometries and reconstruction. For calorimetry detailed track- and tracking algorithms for all or part of the subde- ing programs as implemented in GEANT are very tectors, or by replacing detailed tracking and time consuming, due to the detailed geometry and GEANT all together by simple parameterizations material descriptions, the tracking down to very and smearing, which give reconstructed quantities small energies and the calculation of all physical or physics objects at the end. processes along the way. The reconstruction meth- Arguments in favour for the latter option, which is ods are generally less time consuming for calorime- driven by faster speed, come particularly from fea- ters. sibility studies of physics channels. For many stud- A fast tracker response package has been devel- ies such a program will be sufficient to evaluate the oped in CMS, called FATSIM, and uses a smearing visibility, signal to background ratios, and trigger method thus offering a fast simulation/reconstruc- needs. Moreover it is inconceivable that for the tion of the tracker response. The package returns multitude of possible SUSY scenarios and corre- reconstructed tracks. The precision of the trans- sponding parameter scans full and detailed simula- verse momentum, angles and impact parameters tion can be afforded. In some LEP experiments, e.g. are parameterized as a function of the transverse DELPHI, a fast simulation program is used for momentum and pseudorapidity. These parameter- many BSM type studies and parameter scans. izations were tuned to CMSIM. The package A fast simulation program, called CMSJET, has describes the detailed simulation results well, but been used extensively in CMS since 1993 for phys- can be used ‘as is’ only for the physics process on ics studies. It is about 1000 times faster than which it is tuned, which is at present tt events; i.e. CMSIM. The typical time for the simulation is only the parameters have to be re-tuned for a particular a few times that needed to generate an event. The physics process. program contains the full ECAL and HCAL granu- For the calorimetry the aim of detailed simulation, larity, energy smearing and longitudinal and trans- as offered by the GEANT toolkit, is a high level of verse shower parameterization, a 4T field, and precision and some predictive power. In practice noise and pile-up options. Charged tracks are this means that the CPU increases essentially lin- smeared, and some physics analysis modules are early with the energy of the shower. A practical available for the delivered reconstructed quantities. compromise can be found by using simplified The program has been tuned on detailed simula- geometries and material descriptions, and using a tion results of CMSIM, but is somewhat outdated at parameterization of the energy distribution of present. showers and proper termination of low energetic An example of a fast simulation package used in particles. In this case the CPU time consumption is real-life analysis is SGV, used in some of the DEL- logarithmic with the shower energy. PHI analyses. Geometries based on planes and cyl- A package which provides such parametrized sim- inders can be implemented. For the tracking it acts ulation and which gained momentum over the as a machine to calculate the covariance matrix, but years is GFLASH. Embedded in GEANT3 it can be also delivers track hits and calorimetric showers. It used to simulate the longitudinal and lateral allows for plug-ins for different shower parameter- shower energy depositions, their fluctuations and izations, particle identification, track finding, etc. correlations. Showers are only parameterized when The package can be easily extended to new geome- they do not extend over cracks, otherwise the tries and detectors, e.g. a version for the TESLA detailed showering of GEANT takes over. This detector exists. allows to keep accurate account of detailed effects Turning to the GEANT based programs, it should in tricky detector regions. While the electromag- be stressed that GEANT4 itself contains a lot of netic shower parameterizations in GFLASH can be handles and components which one can customize used basically off the shelf, the user needs to tune to speed up the simulation. Tailored interfaces the hadronic calorimetry part for any particular allow for plug-ins under full user control, but the detector. The package has been developed in H1, user has to provide the plug-ins. Other useful tools an experiment at HERA for which calorimetry is of

22 CMS Bulletin 01-02 vital importance. It is been used within GEANT3 tion/reconstruction results irrespective the path and tuned to detailed showering in GEANT3 followed to get them. (FLUKA, GHEISHA) and a plethora of testbeam Anybody interested to take part in these discus- data. Together with a simplified geometry and sions and developments can subscribe to the cms- material description, the total speed up is about a fast-simulation mailing list. The talks of the meet- factor of 10 when compared to detailed simulation ing can be found on http://cmsdoc.cern.ch/ with a similar quality. Hence H1 actually decided famos/CERNWorkshop_04.2001/. at an early stage to use the fast simulation for their production of simulated events. submitted by A. De Roeck The experience from CDF, who have adopted this package for their detailed simulation, has been pos- PHYSICS itive. They decided to use GFLASH in 1998 after a The CMS Physics Heavy Ion document (CMS study of most of the sophisticated parameteriza- NOTE 2000/60) has finally been issued. It describes tions on the market. They did not find it hard to the theoretical and experimental possibilities to adapt the hadronic part to their needs. observe and study the Quark-Gluon Plasma (QGP) Fast simulation (and reconstruction) code needs to in CMS. CMS is particularly well suited to observe be collected and embedded in a proper framework. so called "hard probes" of deconfinement i.e. the CMS has installed a project FAMOS, which is a relative suppression within the family of upsilon toolkit for fast simulation and reconstruction soft- and J/psi production, and the jet quenching. The ware. It is meant to be a collection of plug-ins for theoretical and phenomenological aspects are dis- OSCAR and ORCA, of which FATSIM is already an cussed by R.Vogt. example, and standalone applications. Consistency The central issue in the CMS heavy ions physics with the full simulation and reconstruction results program is the reconstruction of muons in the will be imposed. While this may be certainly suffi- extreme occupancy conditions we can have in these cient for developers and sub-detector experts, the collisions. The reconstruction algorithm for user for physics analysis or physics TDR studies dimuons from upsilon and J/psi decays has been will need guidance and well defined program con- devised by O. Kodolova. It can work in conditions figurations to work with. of high tracker occupancy and gives a good effi- Fast simulation developments and studies will now ciency for signal dimuons and at the same time effi- follow two main lines. The first is to explore the ciently suppresses dimuons from uncorrelated speed-up tools available in GEANT4, perhaps particle decays. The efficiency for dimuons from extending this by implementing a GFLASH type of upsilon and for the all-Si tracker for |ηµ| < 0.8 is showering program in collaboration with the 75% for the highest expected multiplicity of 8000 GEANT4 group and other interested groups (CDF, charged particles per unit of rapidity. In the TESLA...). Together with simplified geometry the 0.8 < |ηµ| < 1.2 barrel to endcap transition region performance of such program needs to be a factor the reconstruction efficiency drops to 50%. For the 10 or more faster than the detailed program in multiplicity corresponding to minimum bias Pb-Pb order to be worth the effort. Secondly, a program in events the overall efficiency for dimuons from upsi- the spirit of CMSJET will be needed, not based on lon is about 90%. This algorithm has been devel- GEANT, optimized for performance and speed. opped with a detailed simulation of the CMS This program needs to be yet another factor of 10- detector. At present, the main effort is to transfer 100 faster than the fast GEANT based program. this algorithm from Fortran to C++, and also to improve the efficiency in the mixed barrel-endcap In all it is clear that for any fast simulation pro- region, as well as to extend the muon reconstruc- gram, a detailed simulation will form its basis and tion algorithm up to ηµ = 2.4. Taking into account therefore the development and tuning of the these muon reconstruction efficiencies and purities, detailed simulation needs to be pursued with the the expectations for signal to background ratios in highest priority. Nevertheless in view of the the Y, J/psi and Z regions are discussed by approaching date of the physics TDR it is impera- M. Bedjidian and R. Kvatadze. tive that the avenue of fast simulation gets explored already now. To that end the discussions and topi- The investigation of jet quenching requires a modi- cal meetings will continue in the near future: prac- fication of presently existing algorithms for jet find- tical questions need to be answered, such as ing, so as to be able to work with completely consistency of the different levels of geometries, occupied calorimeters with a mean energy of a few trigger simulation, efficient pile-up treatment, tun- GeV per calorimeter cell. The modified algorithm ing, levels of detail and effects simulated by the dif- devised by I. Vardanian allows to find jets of more ferent programs, etc. A clear requirement expressed than 100 GeV of transverse energy with almost at the meeting was that analyses programs should 100% efficiency in events with maximal multiplic- be able to deal, in a uniform way, with the simula- ity. The most promising signal of jet quenching is to search for a shift from zero in the difference

23 CMS Bulletin 01-02 between the transverse energy of a γ (or a Z) and from a highly boosted τ-decay. Another issue to be the recoil jet in γ+jet (and Z+jet) events. The γ+jet investigated is how efficient is our trigger system balance in a non-quenching regime will be deter- for these τ → 3 prongs decays, both at first level mined from pp or peripheral AA collisions. Trigger and then at higher levels. Up to now it has been and data aquisition aspects for heavy ions running optimized for τ → 1 prong decays. A. Nikitenko is are discussed by G. Wrochna. The CMS program continuing the full-simulation study of A/ → τ τ → for heavy ion collisions potentially also includes H + hadron+hadron where the missing Et pA and γγ interactions. Both topics are discussed in reconstruction plays an important role in the recon- this CMS note. K. Hencken points to interesting structed A/H Higgs mass resolution. A possible results concerning predictions and possiblity of extension of these studies should also incorporate experimental observation in γγ events and W. Geist τ → 3 prongs decays. discusses in detail the potential of pA physics. F. Moortgat is mapping the SUSY parameter space During the last CMS week R. Vogt presented in a where A/H → neutralino+neutralino → 4l± decays plenary session the most recent theoretical expecta- would be observable. This investigation is very tions concerning QGP observables. Among various promising. The H± → chargino+neutralino topics discussed during the dedicated heavy ions → 3l±decay channel seems much less promissing at meeting, P. Yepes and B. Wyslouch showed the this stage, more work is needed. F. Charles and experimental setup and results obtained during the A. Albert, generalizing the earlier study by recent run of RHIC. P. Yepes will provide an event S. Abdullin within SUGRA, are now mapping the generator adapted to studies of γγ events for CMS. SUSY (squark and gluino) reach of CMS in the L. Sarycheva and V. Korotkih discussed some pos- more general MSSM scenario. L. Rurua and sible ways to estimate the luminosity using γγ G. Segneri are developping methods allowing to events. look for the lighter stop, much still remains to be The main tasks now are to further elaborate the done in this field, and more generally in under- heavy ions program of CMS, to produce a large standing how to reconstruct sparticle masses. sample of heavy ion events to realistically evaluate We have also just started to look into experimental trigger rates for upsilon, J/psi, Z, jets, and to adapt signatures of extra dimensions in CMS. P. Traczyk the existing OO proton-proton production recon- and G. Wrochna showed first results of possible struction chain to heavy ion simulations. massive graviton decays to lepton pairs. Much We now briefly review the usual topics investi- remains to be done in this domain for CMS, first gated in the physics group. I. Puljak has renewed/ understanding the signatures in the various scenar- → 4 ± ios, then being sure that we trigger efficiently on updated the study of H e in the mH ~130GeV region, but now with full, detailed simulations in such events. Very recently T. Rizzo - expert on the the ORCA framework. R. Kinnunen is looking at Randall-Sundrum-type extra dimension scenario, how to increase the reach in H± → τν studies by made a very interesting presentation in CMS. incorporating τ → 3 charged prong decays. The submitted by O. Kodolova potential gain at high A, H mass is significant. and D. Denegri N. Stepanov is looking into the reconstruction efficiency for topologies with three very close tracks

24 CMS Bulletin 01-02 CCMMSS DDooccuummeennttaattiioonn

CMS DOCUMENTS CMS NOTE/2001 - 021: K. Lassilla-Perini, Jet Rejec- tion with Matching ECAL Clusters to Pixel Hits. It is considered useful to establish information on the first employment of CMS doctoral students CMS NOTE/2001 - 022: M.N. Dubinin, Higgs → γγ upon completion of their theses. Therefore it is Boson Signal in the Reaction pp + 2 Forward requested that Ph.D students inform the CMS Sec- Jets. retariat about the nature of employment and name CMS NOTE/2001 - 023: E. Migliore, Investigations of their first employer. of Operating Scenarios for the Sensors of the CMS The Notes, Conference Reports and Theses pub- Silicon Tracker. lished since the previous CMS Week are listed in CMS NOTE/2001 - 024: J.-M. Le Goff et al., A Com- each Bulletin. Any CMS student awarded a Ph.D ponent Based Approach to Scientific Workflow should send one copy of the thesis to the CMS Sec- Management. retariat (c/o Madeleine Azeglio or Delphine CMS NOTE/2001 - 025: J.-M. Le Goff et al., Object Labrousse). Serialization and Deserialization Using XML. The CMS Notes, CMS Conference Reports and CMS NOTE/2001 - 026: J.-M. Le Goff et al., The CMS Internal Notes can be found at: Reification of Patterns in the Design of Description- http://cmsdoc.cern.ch/documents.html Driven Systems. The procedure for the submission of these docu- CMS NOTE/2001 - 027: M. Brugger et al., Drift ments can be found at the same address. Tube based Pseudorapidity Assignment of the Level-1 Muon Trigger for the CMS Experiment at CERN. CMS NOTES CMS NOTE/2001 - 028: G.M. Dallavalle et al., Anti- CMS NOTE/2001 - 010: J. Damgov and V. Genchev, fuse-FPGAs for the Track-Sorter-Master of the CMS Non-Linear Energy Calibration of CMS Calorime- Muon Barrel Drift Tubes: Design Issues and Irradi- ters for Single Pions. ation Test. CMS NOTE/2001 - 011: D. Acosta et al., Results on CMS NOTE/2001 - 029: S.I. Bityukov et al., The L2 Trigger Reconstruction in Single and Di-Muon LHC (CMS) Discovery Potential for Models with Topologies. Effective Supersymmetry and Nonuniversal Gaug- CMS NOTE/2001 - 012: G. Bruno and M. Konecki, ino Masses. Simulation of the Baseline RPC Trigger System for CMS: Efficiency and Output Rates in Single Muon Topology. CMS CONFERENCE REPORTS CMS NOTE/2001 - 013: R. Wilkinson, Simulating CMS CR/2001 - 002: Rajwant Kaur et al., Prelimi- the Endcap Muon CSC System in ORCA. nary study of the top mass determination in the dilepton(e-mu) channel at LHC, Workshop on CMS NOTE/2001 - 014: Z. Aftab et al., Test Beam Physics with CMS at the LHC, Tata Institute of Fun- Results of the Forward RPC Prototype Chamber for damental Research, India, December 11-15, 2000. the CMS Muon Detector. (Files not yet available). CMS NOTE/2001 - 015:A. Bhardwaj et al., Tech- CMS CR/2001 - 003: R. Dell’Orso on behalf of CMS niques of Improving the Breakdown Voltage of Si Tracker Collaboration, Recent Results for the CMS Microstrip Preshower Detector. Tracker Silicon Detectors, IEEE Nuclear Science CMS NOTE/2001 - 016: M. Petertill and P. Schmitz, Symposium and Medical Imaging Conference, Readout and Calibration of CMS Pipeline Chips to Lyon, France, October 15-20, 2000. Examine the Signal Development of Tracking Strip CMS CR/2001 - 004: Sunanda Banerjee, TIFR- Detectors. EHEP, Mumbai, India, Prospects of B-Physics with CMS NOTE/2001 - 017: D. Kotlinski et al., Study of CMS, Beauty 2000, Magan, Israel, September, 2000. a Level-3 Tau Trigger with the Pixel Detector. CMS CR/2001 - 005: F. Moortgat, Observability of CMS NOTE/2001 - 019: S. Lehti, Tagging b-Jets in MSSM Higgs Bosons decaying to sparticles at the → ττ bb HSUSY . LHC, 36th Rencontres de Moriond, QCD and High CMS NOTE/2001 - 020: I. Dumanoglu et al., Radia- Energy Hadronic Interactions, Les Arcs, France, tion-Hardness Studies of High OH Content Quartz March 17-24, 2001. Fibers Irradiated with 500 MeV Electrons at CERN. (Files not yet available).

25 CMS Bulletin 01-02

THESIS E. Ozkapici: Search for H → ZZ → lljj in Vector M. Brugger: Drift Tube based Pseudorapidity Boson Fusion at CMS Experiment at the Large Assignment of the Level-1 Muon Trigger for the Hadron Collider, January 2001, Middle East Techni- CMS Experiment at CERN, February 2001, Technis- cal University (METU), Physics Department, chen Universitat Graz, Graz, Austria (CMS THESIS Ankara, Turkey (CMS THESIS / 2001-012). Master / 2001-016). Diploma Thesis. of Science (M.Sc.) Thesis. 0 0 Z. Xie: The measurement of B s B s oscillations: perspectives at LHC with CMS and experimental JOB OPPORTUNITIES limit at LEP with ALEPH in exclusive decay channels, April 11, 2001, Scuola Normale Superiore, A list of vacancies in CMS and other institutes is Classe di Scienze, Corso di Perfezionamento in posted on the Web (http://cmsdoc.cern.ch/jobs/ Fisica, Pisa, Italy (CMS THESIS / 2001-018). P.h.D. news.html). Thesis.

26 CMS Bulletin 01-02 CCMMSS CCaalleennddaarr 22000011 12-Jun-01 LHCb ATLAS DELPHI LHCC (4-5) OPAL (Ext.) OPAL LEB - RB (13) FC (7) / RB (5) OPAL - SPC/FC/CC/C OPAL ALICE - LHCC (21-22) Magnet Conf. / ALEPH ATLAS / ALEPH DELPHI ATLAS CMS & Non-CMS Meetings LHCC (3-4) - Comp. Rev.? ALICE - LHCb SPC/FC/CC LHC Symp. (Sard.) (25-28) http://cmsdoc.cern.ch/calendar.html ESSC (22) CMS WEEK CMS WEEK CMS Meetings ME(14/15)Fermi ESSC (16) ECAL Week ECAL Referees (1) Referees (2) RRB (22-23) Referees (19) MB/FB(15,16) 1-Oct 3-Dec 5-Nov Week CPT Week MU 6-Aug 23-Jul TCM 22-Oct 10-Sep TCM 10-Dec TCM 26-Nov 12-Nov SC 27-Aug SC FB 20-Aug 13-Aug Holidays at CERN during this week 44 29-Oct TCM47 19-Nov Week TK 5 1 17-Dec 5 2 24-Dec 41 8-Oct42 15-Oct TCM 2 829 9-Jul 16-Jul TCM Week TK 26 25-Jun2 7 2-Jul TCM RB: Research Board SPC/FC/CC/C 5 0 DELPHI 3 5 SPC/FC/CC 3 7 TLAS - ALICETLAS - 3 4 LHCC (21-22) 3 8 17-Sep LHCb - RB (15) 3 3 ALEPH / DELPHI 3 0 (5) / ALEPH DELPHI 4 0 LHCC (31/01-01/02) 31 30-Jul Lehman Review - LHCb SPC 4 5 CMS & Non-CMS Meetings Week Monday ESSC (23) 4 3 CMS WEEK ECAL WeekECAL ALICE / DELPHI 4 8 ECAL Week ECAL nn. Rev. Reportnn. Rev. A CMS Meetings ME(15/16)CERN - OPAL ME(23/24)UCLA CMS WEEK (CATANIA) MB(Video) RRB (23-24)W. /MU/CPT TK MB/FB (9,10) Referees (19) Referees (14)Week Electr. LHCC (16-17) 4 6 Referees (29) 9 26-Feb TCM 8 19-Feb 23 8-Jan 4 15-Jan5 22-Jan6 29-Jan SC 7 TCM 5-Feb 12-Feb Week SC TK TCM FB 3 2 1 1-Jan 2 324 4-Jun 11-Jun SC (7) RB 4 9 18 30-Apr1 9 7-May TCM 2 1 21-May2 2 SC 28-May TCM 25 18-Jun FB US 15 9-Apr 16 16-Apr 17 23-Apr 1 011 5-Mar 12-Mar TCM OPAL 3 6 3-Sep 1 2 19-Mar 1 3 26-Mar14 2-Apr MB TCM Computing RB 3 9 24-Sep 2 0 14-May 5 2 25-Dec SC: Steering Committee MB: Management Board FB: Finance Board TCM: Technical Coordination Meet. (always on Monday)ESSC: Electronics Systems Steering CommitteeSoftware/Computing/PRS/TRIDAS Core CPT: ME: CMS Endcap Muon Group Meet.RRB: Resources Review Board LEB: LHCC Electronics Board SPC: Scientific Policy Committee Committee Finance FC: Council of Committee CC: C: Council Week Monday

27 CMS Bulletin 01-02 MMoonntthhllyy CCaalleennddaarr June 01 July 01

Date Day CMS Meetings CMS & non-CMS Meetings Date Day CMS Meetings CMS & non-CMS Meetings 1 FriECAL Week ALICE / DELPHI 1 Sun 2 Sat 2 Mon Referees 3 Sun 3 Tue 4 Mon 4 Wed LHCC 5 Tue 5 Thu LHCC 6 Wed 6 Fri 7 Thu RB 7 Sat 8 Fri 8 Sun 9 Sat 9 Mon TCM / TK Week 1 0 Sun 1 0 Tue TK Week 11 MonSC SPC / OPAL 11 Wed TK Week 1 2 Tue SPC / OPAL 1 2 Thu TK Week 1 3 Wed FC / OPAL 1 3 Fri TK Week 1 4 Thu CC / OPAL 1 4 Sat 1 5 FriMuon Endcap (CERN) C / OPAL 1 5 Sun 16 SatMuon Endcap (CERN) 16 Mon ESSC 1 7 Sun 1 7 Tue 18 MonCMS Week (Catania) 18 Wed 1 9 TueCMS Week (Catania) 1 9 Thu 2 0 WedCMS Week (Catania) 2 0 Fri 21 ThuCMS Week (Catania) 21 Sat 22 FriCMS Week (Catania) 22 Sun 23 Sat 23 Mon TCM 2 4 Sun 2 4 Tue 2 5 MonTCM ATLAS / ALEPH / DELPHI 2 5 Wed 2 6 Tue ATLAS / ALEPH / DELPHI 2 6 Thu 2 7 Wed ATLAS / ALEPH / DELPHI 2 7 Fri 2 8 Thu ATLAS / ALEPH / DELPHI 2 8 Sat 2 9 Fri ATLAS / ALEPH / DELPHI 2 9 Sun 30 Sat 30 Mon 31 Tue

August 01 September 01

Date Day CMS Meetings CMS & non-CMS Meetings Date Day CMS Meetings CMS & non-CMS Meetings 1 Wed 1 Sat 2 Thu 2 Sun 3 Fri 3 MonECAL Week OPAL 4 Sat 4 TueECAL Week OPAL 5 Sun 5 WedECAL Week OPAL 6 Mon 6 Thu 7 Tue 7 Fri OPAL 8 Wed 8 Sat 9 Thu 9 Sun 1 0 Fri 1 0 MonTCM LEB (Stockholm) 11 Sat 11 Tue LEB (Stockholm) 1 2 Sun 1 2 Wed LEB (Stockholm) 1 3 Mon 1 3 Thu RB/LEB (Stockholm) 1 4 Tue 1 4 FriME (Fermi) LEB (Stockholm) 1 5 Wed 1 5 Sat ME (Fermi) 16 Thu 16 Sun 1 7 Fri 1 7 MonAnnual Reviews ALICE/LHCb/SPC 1 8 Sat 1 8 TueAnnual Reviews ALICE/LHCb/SPC 1 9 Sun 1 9 WedAnnual Reviews ALICE/LHCb/FC 2 0 Mon 2 0 ThuAnnual Reviews ALICE/LHCb/CC 2 1 Tue 2 1 FriAnnual Reviews ALICE/LHCb 2 2 Wed 2 2 Sat 23 Thu 23 Sun 2 4 Fri 2 4 MonCMS Week/Magnet Conf. ALEPH 2 5 Sat 2 5 TueCMS Week/Magnet Conf. ALEPH 2 6 Sun 2 6 WedCMS Week/Magnet Conf. ALEPH 2 7 MonSC 2 7 ThuCMS Week/Magnet Conf. ALEPH 2 8 TueFB 2 8 FriCMS Week/Magnet Conf. ALEPH 2 9 Wed 2 9 Sat 30 Thu 30 Sun 3 1 Fri 14/6/01

28 CMS Bulletin 01-02 CCMMSS GGeenneerraall IInnffoorrmmaattiioonn

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