DOCSLIB.ORG

STANFORD Tidying up Charmonium

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
STANFORD Tidying up Charmonium The SPEAR electron-positron storage ring at SLAC, After first generation detectors discovered charmonium, new experiments are now uncovering the details of the rich charmonium spectroscopy. (Photo SLAC) tion has been mounting that under different conditions, new forms of nuclear matter are possible (see December 1980 issue, page 404). The behaviour seen in the heavy ion experiments at Berkeley cannot be explained if the secondary frag­ ments are ordinary particles, and one suggestion is that evidence is being seen for a new type of nuclear matter. While still made up of quarks, this new metastable nuclear material has its component quarks in configurations very different to those of normal particles. Experi­ ments are continuing to study the behaviour of these short-lived colli­ sion fragments. STANFORD Tidying up charmonium Charmonium is the family name given to mesons composed of a charmed quark bound to a charmed spectroscopy of triplet charmonium monium. They had definite ideas for antiquark. The discovery in 1 974 of states has been uncovered. the mass of the eta-c, which did not the first charmonium state, the J/ However their singlet counter­ agree with the preliminary informa psi, at Brookhaven and at SLAC parts have proved to be much harder tion from DORIS. heralded the arrival of a new era in to find, and for good reasons. Char­ Then new data began to come the study of elementary particles, monium normally comes from ener­ through from new detectors at the the so-called 'New Physics'. The getic photons, produced for example SPEAR electron-positron ring at existence of this new quantum num­ from the annihilation of colliding SLAC (see September 1979 issue, ber was one vital clue which radically electrons and positrons. Because page 246). Playing a prominent role changed our understanding of the the photon itself carries spin one, the in this search was the Crystal Ball basic forces in Nature. Since then selection rules for these reactions detector (a Caltech / Harvard / the careful study of charmonium say that only spin one charmonium Princeton / SLAC / Stanford colla­ spectroscopy has gone on to provide states can be formed directly. In boration). This spherical array of 672 much valuable information on quark experiments with colliding electron- sodium iodide crystals, each viewed dynamics. positron beams, singlet charmonium by a photomultiplier, gives good Charmed quarks and their antipar- shows up only in the subsequent angular coverage of the electron- ticles each carry intrinsic angular decays of the triplet variety, and is positron collision region, and good momentum (spin) of half a unit, and correspondingly more elusive. measurement of low energy photons according to the rules can combine Preliminary reports of the ground produced in the decay of triplet char­ together either with their spins state spin zero charmonium, now monium. parallel (a triplet state), giving a called the eta-c, came from experi­ These 'radiative' decays can pro­ meson of spin one, or with their spins ments at the DORIS electron-posi­ duce a variety of secondary char­ antiparallel (a singlet state), forming tron ring at DESY. Theoreticians had monium states, and the photon a spin zero particle. The J/psi has already deduced much from the spectrum from the Crystal Ball spin one, and since 1974, a rich unfolding spectrum of triplet char­ showed sharp peaks corresponding 68 CERN Courier, March 1981 to transitions between different tri­ At present, the characteristics of the mediated by the exchange of so- plet charmonium levels, in much the state are highly suggestive of the called gluons, similar in some res­ same way that sharp spectral lines eta-c, but further work is needed. pects to the photon exchange res­ show up when ordinary atoms are Elsewhere in the photon spectrum ponsible for the familiar electromag­ excited. In addition, a small but sta­ from radiative charmonium decays, netic force. As well as transiently tistically significant peak was seen in the Crystal Ball shows evidence for flitting between quarks, these gluons the spectrum corresponding to a decays producing a meson of mass should also be able to stick together new charmonium state of mass 1420 MeV. A small sample of spe­ to form 'gluonium' or 'glueballs'. 2983 MeV. Some months later, the cific decay modes for a meson of this Whether the E-meson signal seen in Mark II group (Berkeley / SLAC), mass was also reconstructed by radiative charmonium decays is a announced the first evidence for a both Mark II and the Crystal Ball. A glueball or not remains to be sett­ specific eta-c decay mode, while spin one meson of this mass, the E, led. another decay mode was found by has been known for some time With Mark II having already the Crystal Ball shortly afterwards. through the analysis of bubble moved to the bigger PEP ring, the This was already sufficient to make chamber exposures to hadron Crystal Ball is presently the only theoreticians feel better, but to pin beams. detector operating at SPEAR. Even down this new candidate charmon­ In the Crystal Ball, the radiative though its move to PEP has been ium state, its quantum numbers first transitions producing E-mesons ap­ approved, this will not take place for had to be fixed. peared to be quite copious, and this at least a year. An important task The Crystal Ball is well suited to led some people to speculate that remaining at SPEAR is to continue to measure electromagnetically show­ the E, rathe/ than being a conven­ search for the F-meson, carrying ering particles like electrons and tional meson built up of a quark and both charm and strangeness. F can­ photons. To handle charged hadrons an antiquark, could be an example of didates have now been reported required more work, and further evi­ a 'glueball' — a new type of matter from experiments at several Labora­ dence in favour of an eta-c assign­ much talked about but never before tories, but as yet none from SPEAR. ment for the new state came from seen. Other objectives include more eta-c analysis of channels containing ap­ Current thinking says that quarks data and a scan of the SPEAR energy propriate combinations of hadrons. interact through the 'colour' force regions so far largely neglected. Physics monitor soon come within the reach of labo­ Various characteristics of the Ultrahigh energy ratory experiments. fragmentation region of inelastic cosmic rays Meanwhile the cosmic ray spe­ hadron-nucleus interactions were cialists continue their studies, and covered, and detailed comparison of Cosmic ray experiments have tradi­ from 20-29 October, the city of the comparable data obtained by all tionally provided physicists with Nakhodka in the Soviet Far East was three groups shows quite reasona­ glimpses of behaviour beyond the host to a Soviet-Japanese sympo­ ble agreement in a number of res­ energy range attainable with artifi­ sium on processes at ultrahigh ener­ pects. cial particle beams. However with gies in cosmic rays, investigated 1. The cross-section of the hadron the CERN antiproton project promis­ using emulsion chambers exposed inelastic interaction with an air ing to provide collision energies at altitude. There were participants nucleus still increases at least up to equivalent to those of 1 55 000 GeV from the Japanese/Brazilian colla­ energies of 1015eV at nearly the beams, and with the prospect of boration at Mount Chacaltaya in the same rate as at accelerator ener­ ISABELLE at Brookhaven going Andes, from the group carrying out gies. even higher, physicists hope that experiments on Mount Fuji, Japan, 2. At ultrahigh energies there is con­ some of the exotic behaviour and from the 'Pamir' Soviet-Polish siderable deviation of scaling not reported from cosmic ray studies will collaboration. only in pionization but also in the CERN Courier, March 1981 69 .
Load more

Recommended publications
  • ISABELLE DESIGN Studyk
    © 1973 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. ISABELLE DESIGN STUDYk F. E. Mills Brookhaven National Laboratory Upton, New York Introduction Intersection Regions Following the 1970 BNL Summer Study on AGS Utili- The philosophy of design of the intersection re- zation, John Blewett and I began to consider the design gions is to remove the momentum dispersion, allow the of colliding beam systems in the center of mass energy beam to spread in size, to pass it through a strong range from 200 GeV to 2000 GeV, since it seemed to us lens and bring it to a small focus at the intersection then that significant new phenomena could be expected region (low p). The process is then reversed to return in nuclear interactions in that energy range. We took it to the normal lattice. In some cases (elastic as initial conditions, that we would employ the emer- scattering), the beam is kept large, to obtain good gent technology of superconducting magnets, and that angular resolution. What we have done is to design a we would employ the AGS as the injector, hence requir- "catalog" of intersecting regions, in cooperation with ing the acceleration of the full stored beam to final experimentalists, to fit the needs of particular exper- energies in the storage device. In the summer of 1971, iments.
    [Show full text]
  • A Pp and E+E- Collider in a 100Km Ring at Fermilab
    A pp and e+e- collider in a 100km ring at Fermilab Tanaji Sen In collaboration with C.M.Bhat, P.C. Bhat, W. Chou, E. Gianfelice-Wendt, J. Lykken, M.K. Medina, G.L. Sabbi, R. Talman 5th TLEP Workshop July 25-26, 2013 Fermilab Outline Motivation • Snowmass study • TLEP design study in a 80 km ring • Past studies of VLHC and VLLC in a 233 km ring in 2001 • Now a “more modest” ring of circumference = 100 km • Design of a pp collider with 100 TeV CM energy • Design of an e+e- collider with 240-350 GeV CM energy • No discussion of - Cost - Politics of acquiring 100 km of real estate T. Sen pp and e+e- colliders 2 Hadron Colliders - Wikipedia Hadron colliders Intersecting Storage Rings CERN, 1971–1984 Super Proton Synchrotron CERN, 1981–1984 ISABELLE BNL, cancelled in 1983 Tevatron Fermilab, 1987–2011 Relativistic Heavy Ion Collider BNL, 2000–present Superconducting Super Collider Cancelled in 1993 Large Hadron Collider CERN, 2009–present High Luminosity Large Hadron Proposed, CERN, 2020– Collider Very Large Hadron Collider Theoretical T. Sen pp and e+e- colliders 3 Hadron Colliders ISR SPS Tevatron RHIC (pp) LHC (2012) Circumference [km] 0.94 6.9 6.3 3.8 26.7 Energy [GeV] 31 315 980 255 4000 Number of bunches dc 6 36 107 1380 Bunch spacing [ns] - 1150 396 108 50 Bunch intensity [x1011 ] - 2.75 (3.1/1 ) 2.0 1.7 Particles/beam [x 1014] 9.8 7.8/4.2 112/36 143 3089 Trans. rms Emitt [ μm] 1.5/0.15 (3/1.5) 3.3 2.5 Beam-beam tune shift 0.0035x8 0.005x3 0.013x2 0.007x2 0.01x2 Luminosity [x1032 cm-2s-1] 1.3 0.06 4.0 2.3 77 # of events/crossing 12 37 Stored beam energy [MJ] 0.005 0.04 1.75/0.57 0.57 140 T.
    [Show full text]
  • SCOPE of the WORKSHOP D. Cline Fermi National
    SCOPE OF THE WORKSHOP D. Cline Fermi National Accelerator Laboratory and University of Wisconsin at Madison A Workshop was held during the week of March 1. The very interesting talk of R. Feynman on 27-31 at the Lawrence Berkeley Laboratory in ultra high energy interactions (Ua) and the historical Berkeley, California. The purpose of the Workshop surveys of beam cooling by A. Sessler and was to discuss various beam-cooling techniques and to R. R. Wilson. investigate the possibility of constructing high luminosity proton-antiproton storage rings. 2. The general conviction that pp machines pro­ Herman Grunder and other members of the LBL staff posed in the present CERN and Fermilab schemes are were largely responsible for the efficient operation of sound (UIc, d; IVc; Vb). the Workshop and the success. The Workshop was jointly sponsored by Fermilab and LBL. 3. The discussion of the cooling of high energy That this was the first workshop totally devoted proton-antiproton beams by electrons (Rubbia, Month, to beam cooling and to high luminosity pp storage rings Ruggiero) or by synchrotron radiation (Wilson). The indicates the close coupling between the two subjects. report of Ruggiero, Vh, was completed after the The construction of pp storage rings is an old dream Workshop and is reproduced here for completeness. of accelerator physicists, the practical realization of these machines certainly relies on beam-cooling tech­ 4. The understanding of improvements in target niques. The late G. Budker often discussed the possi­ efficiency that can raise the p yield by a considerable bility of pp storage rings and realized that beam factor (IVd).
    [Show full text]
  • People and Things
    People and things On people Among the awards distributed at the recent joint annual meeting of the American Physical Society and the American Association of Phy­ sics Teachers were the Dannie Heineman Prize for Mathematical Physics, to John C. Ward of Mac- quarie University, Australia, for his contributions to the development of particle gauge theories, and the Oersted Medal for physics teach­ ing, to 1.1. Rabi of Columbia Univer­ sity. LEP people Now that the LEP electron-positron collider project is under way at CERN, decisions have been taken on the management of the machine construction and on preparations for the experimental programme. At CERN itself, a LEP Manage­ ment Board has been set up to sending institution. We have advised One of the international discussion panels study and propose solutions to at the Pan American Symposium on High and encouraged the first user group Energy Physics and Technology, held at major problems of the construction from Mexico. We are seeking mod­ Cocoyoc, Mexico, in January. Left to right, programme and to share respon­ est Foundation and International R. Taylor from SLAC (representing Canada), sibility for major decisions concern­ Fermilab Director Leon Lederman Agency support in order to minimize (representing the US), J. Flores of Mexico, ing the project. The members of the problems of government involve­ M. Kreisler of the US, C Avilez of Mexico, the Board (appointed for two ment. Agreements between institu­ and Burt Richter also from SLAC, years) are E. Picasso (Chairman), representing the US. tions are simple to administer and G. Plass, H. Laporte.
    [Show full text]
  • Deliberation Document on the 2020 Update European Strategy
    DELIBERATION DOCUMENT ON THE 2020 UPDATE OF THE EUROPEAN STRATEGY FOR PARTICLE PHYSICS The European Strategy Group _Preface The first European Strategy for Particle Physics (hereinafter referred to as “the Strategy”), consisting of seventeen Strategy statements, was adopted by the CERN Council at its special session in Lisbon in July 2006. A first update of the Strategy was adopted by the CERN Council at its special session in Brussels in May 2013. This second update of the Strategy was formulated by the European Strategy Group (ESG) (Annex 1) during its six-day meeting in Bad Honnef in January 2020. The resolution on the 2020 Update of the European Strategy for Particle Physics was adopted at the 199th Session of the CERN Council on 19 June 2020. The ESG was assisted by the Physics Preparatory Group (Annex 2), which had provided scientific input based on the material presented at a four-day Open Symposium held in Granada in May 2019, and on documents submitted by the community worldwide. In addition, six working groups (Annex 3) were set up within the ESG to address the following points: Social and career aspects for the next generation; Issues related to Global Projects hosted by CERN or funded through CERN outside Europe; Relations with other groups and organisations; Knowledge and Technology Transfer; Public engagement, Education and Communication; Sustainability and Environmental impact. Their conclusions were discussed at the Bad Honnef meeting. This Deliberation Document was prepared by the Strategy Secretariat. It provides background information underpinning the Strategy statements. Recommendations to the CERN Council made by the Working Groups for possible modifications to certain organisational matters are also given.
    [Show full text]
  • Toward the Limits of Matter: Ultra-Relativistic Nuclear Collisions at CERN
    EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN-OPEN-To be specified 21 May 2015 Toward the Limits of Matter: Ultra-relativistic nuclear collisions at CERN Abstract Strongly interacting matter as described by the thermodynamics of QCD undergoes a phase transi- tion, from a low temperature hadronic medium to a high temperature quark-gluon plasma state. In the early universe this transition occurred during the early microsecond era. It can be investigated in the laboratory, in collisions of nuclei at relativistic energy, which create ”fireballs” of sufficient energy density to cross the QCD Phase boundary. We describe 3 decades of work at CERN, devoted to the study of the QCD plasma and the phase transition. From modest beginnings at the SPS, ultra- relativistic heavy ion physics has evolved today into a central pillar of contemporary nuclear physics and forms a significant part of the LHC program. Jurgen¨ Schukraft PH Division, CERN, CH-1211 Geneva 23, Switzerland Reinhard Stock Institute of Nuclear Physics, and FIAS, Max von Laue Strasse 1, D-60438 Frankfurt/Main, Germany arXiv:1505.06853v1 [nucl-ex] 26 May 2015 To appear in “60 Years of CERN Experiments and Discoveries”, Editors H. Schopper and L. di Lella, World Scientific Publishing, Singapore, 2015 Toward the Limits of Matter: Ultra-relativistic nuclear collisions at CERN 1 1 Strongly interacting matter We recall here the development of a novel research field at CERN, devoted to the phases and phase structure of matter governed by the strong fundamental force. Its proper field theory was discovered around 1970: Quantum Chromodynamics (QCD) addresses the fundamental interactions of elementary quarks, as mediated by gluons.
    [Show full text]
  • James W. Rohlf Feb
    James W. Rohlf Feb. 2017 Contact Boston University Physics Dept., 590 Commonwealth Ave., Boston, MA 02215, phone 617-353-2600, mobile 617-543-7455, Skype 617-275-3636, CERN +41754112573 email [email protected] Education Ph.D. in Physics 1980 Caltech, ”Investigations of Hadron Jets,” published in Nucl. Phys. B171 (1980) p. 1-37, Committee: G. C. Fox (advisor), C. Barnes, R. P. Feynman, R. Gomez M.S. in Physics 1975 University California, Los Angeles B.A. Physics and B.S. Mathematics 1973 University of Minnesota Employment Professor of Physics, Boston University, 1988 - present Associate Professor of Physics, Harvard University, 1985-8 Assistant Professor of Physics, Harvard University, 1981-5 (concurrent with Cornell and CERN) Scientific Associate (paid), European Center for Nuclear Research (CERN), 1982-4 Visiting Fellow, Laboratory of Nuclear Studies, Cornell University, 1980-2 Research Associate, Harvard University, 1980-1 Research Associate, California Institute of Technology, 1979-80 Current research Physics with the Compact Muon Solenoid (CMS) detector at the CERN LHC. First data col- lected in Dec. 2009. First physics paper published in Feb. 2010. Design and construction of the data concentrator (DCC and DCC2) to read out the CMS hadron calorimeter (HCAL) and other associated electronics ($5 M equipment money). Development of silicon photomultipliers (SiPM) and micro-CTA electronics (AMC13) for trigger, clock, and data acquisition in CMS. Led effort to establish source calibration procedure for calorimeter. Supervision of postdocs and and gradu- ate students. Work closely with the senior engineers at the Boston University Electronics Design Facility. Operations and detctor upgrades funded by US Department of Energy.
    [Show full text]
  • RCED-91-116 Federal Research: Status of DOE's Superconducting
    ._ * United States General Accounting Office -,_ Report to the Chairman, Committee on GAO the Budget, U.S. Senate April 1991 FEDERAL RESEARCH Status of DOE’s Superconducting Super Collider GAO,‘RCED-91-116 United States General Accounting Office GAO Washington, D.C. 20548 Resources, Community, and Economic Development Division B-227295.8 April 151991 The Honorable Jim Sasser Chairman, Committee on the Budget United States Senate Dear Mr. Chairman: In response to your March 7,1990, request we reviewed the status of the Department of Energy’s (DOE) Superconducting Super Collider (ssc), which will be located 30 miles south of Dallas, Texas. The ssc will be the world’s largest high energy particle accelerator-a research tool used by physicists to seek fundamental knowledge about energy and matter. DOE recently estimated that the ssc will cost $8.2 billion (in current-year dol- lars).’ You expressed concern that once the project progressed beyond the design phase, other problems could lead to further cost increases. As agreed with your office, this report provides information on the insta- bility in tenure of DOE and ssc Laboratory project management, uncer- tainties related to the ssc site geology, uncertainties and risks with magnet development and production, and Texas’ proposed contribution to the project’s costs. Both the ssc Laboratory and DOE’S ssc program office have experienced Results in Brief management instability because acting directors that have occupied key positions have frequently changed. In general, instability in key leader- ship positions can result in frequent changes of direction, diminished accountability, and little long-term operational planning.
    [Show full text]
  • Proton-Proton Colliding Beam Facility ISABELLE
    XI Intern, Conf» on High Energy Accelerators, Geneva, Switzerland, July 7-11, 1980= BNL 28019 H. Hahn' Brookhaven National Laboratory, Upcon, New York, 11973, USA. ABSTRACT This paper attetnpeo Co present. Che status of Che ISABELLE conotructioa project, uhich has Che objeccive of building a 400 * 600 GGV proton colliding beam facility. The major technical features of cho auperconduccing accelerators with their projected performance are described. Progress made so far, difficuleieo encountered, and Che program until completion ia 1986 is briefly reviewed. INTRODUCTION About one month ago Brookhaveu Nacional Laboratory celebraced the 20th anniversary of Che Alternating Gradient Synchrocon. This venerable accelerator has been Che instrument by which many significant discoveries were made. In order to continue its role as high energy physics center, studies for a proton—proton colliding beam facilicy were actively pursued at Broolthaven since Che early 1970's. ISABELLE, as this Intersecting Storage Accelerator wao baptized, made ics debut at the 8th International Conference on High Energy Accelerators here in Geneva in 1971^. The story goes chat Che AGS cons truce ion wao approved by the US Atonic Energy Commission six days afcer reception of Broolthaven • s leccer. This time it cook more then six years and Che writing of six design studieo^' before Che new accelerator Has recognized by authorizing Construction Planning 4 Design funds for Fiscal Year 1976 and 1977. Preliminary design was approved in Fi' 7(i and authorisation for construction followed then without further delay in FY 793). Froa its inception, ISABELLE was intended to serve as a major high energy facility which implied the following design criteria.
    [Show full text]
  • Presented at IV All-Union National Cii/Vierence on Particle Accelerators, Moscow, November 18-20, 1974 BNL 19280
    't Presented at IV All-Union National Cii/vierence on Particle Accelerators, Moscow, November 18-20, 1974 BNL 19280 -NOIICE- ThU report was prepared » an account or work sponsored bv the Unlled SlaKJ Government Neither he United States nor th. United Suits Atom.c Energy Commission, nor any of their employees, nor any of ihelr contractors, subcontractors, or their employees, nikes «y trarranty, expreu a, iropUed. or assumes any Srt lliwutT" responsibility for the accuracy, com. plctenso or usefulness of any information, apparatus, KodSel o? process disclosed, or represents that its use would not infringe privately owned tigh.s. ISABELLE - SUPERCONDUCTING STORAGE ACCELERATOR The Brookhaven Staff - Presented by Mark Q. Barton Brookhaven National Laboratory For some years the Brookhaven staff has studied various possible new accelerators that could make significant contributions to the research capability of the overall high energy physics program. This effort has been split into studies of possible machines and an explicit research and development program on superconducting magnets which are believed desirable for the next generation of machines. In 1970 following suggestions by J.P. Blewett these efforts focused on storage rings having the unique fea- ture that the beams would be stacked at 30 GeV using the BNL AGS as injec- tor then accelerated to a higher energy in the storage rings. By 1972 a preliminary conceptual design of a 200 GeV colliding beam facility had been prepared and a summer study was convened, attended by particle physicists and accelerator experts from many U.S. and European laboratories. Subse- quent to this study, the staff has further developed these design concepts 2 so that a formal proposal has been submitted to the USAEC requesting funds for construction.
    [Show full text]
  • DESY the Evidence for the F Meson
    DASP, the double arm spectrometer detector at one of the intersection regions on the DORIS electron-positron storage rings at DESY, photographed when the two arms were pulled back. The central section, which is receiving attention, and the counters, which are visible on the right and on the left, are part of the inner detector elements. DASP was the source of the F meson discovery. (Photo DESY) due to this loss. Firstly, beam scrapers record. On 20 June the polarized ion non-charm quarks. Mesons called D have been mounted above and below source gave a current of 960nA; the made of charm quark and non-strange the beam plane so as to direct any external beam current at 500 MeV was quarks (cG or cd), as well as baryons beam lost vertically to localized spots 120nA with over 70% polarization. carrying charm, have already been on the wall. Secondly, the space The improvement is attributed to found. Mesons consisting of a charm between the tank walls and the cleaning and adjustment of the quark and a strange quark (cs) called F magnet yoke has been filled with matching section between source and mesons were still at large. graphite blocks surrounded by acceleration tube. The source is of the A team from Aachen / DESY / Ham­ boriated gypsum sheets; this has given Lamb shift type with a Sona zero field- burg / Max-Planck-lnstitute, Munich / a factor five improvement in residual crossing region. The design aim was Tokyo reported evidence for the adiation at the centre of the tank and 60 nA.
    [Show full text]
  • Congress of the United States Congressional Budget Office October 1988
    CONGRESS OF THE UNITED STATES CONGRESSIONAL BUDGET OFFICE OCTOBER 1988 A SPECIAL STUDY RISKS AND BENEFITS OF BUILDING THE SUPERCONDUCTING SUPER COLLIDER The Congress of the United States Congressional Budget Office For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 rmin I Ilillilill I NOTES Details in the tables may not add to totals because of rounding. All years in this report are fiscal years, unless otherwise noted. All costs are given in constant fiscal year 1988 dollars, unless otherwise noted. Cover photograph courtesy of the Fermi National Accelerator Laboratory of Batavia, Illinois. The photograph shows a parti- cle interaction in the 15-foot bubble chamber at Fermilab. PREFACE The Superconducting Super Collider (SSC) is a proposed new particle accelerator, which would advance the state of high-energy physics. The next Congress will be faced with the choice of whether to begin construction of the accelerator, pursue an alternative, or defer the de- cision until further research reduces current technological uncertain- ties. In response to a request from the Senate Budget Committee, this special study analyzes the potential risks and benefits of building the SSC. In keeping with the Congressional Budget Office's (CBO) man- date to provide nonpartisan analysis, no recommendations are made. Philip Webre of CBO's Natural Resources and Commerce Divi- sion, assisted by Kuljeet Kalkat, wrote this report under the super- vision of Elliot Schwartz. Everett M. Ehrlich provided valuable assistance in the initial phases of the project. Robert Hunter, Director of the Department of Energy's Office of Energy Research, and Robert Diebold and the Staff of the Department of Energy's SSC Division provided many helpful suggestions and comments.
    [Show full text]