TThhee FFllaavvoouurr ooff TThhiinnggss ttoo CCoommee:: PPrroossppeeccttss ffoorr tthhee SSuuppeerrBB PPrroojjeecctt
SStteevveenn RRoobbeerrttssoonn IInnssttiittuuttee ooff PPaarrttiiccllee PPhhyyssiiccss
Presented at Uniiversiité de Montréall January 29, 2009 OOuuttlliinnee
● Whhatt iss fflavoouurr phhyyssiicss aannd wwhhy iss iiss iinteresstiing?
● The “neeww physsics”” laandsccapee aand ccompleementtaaritty wiithh enerrggy-ffrontiierr meaassuureemmeentss
● The SupperBB pprroojjecct:: - Physics reach - Accelerator - Detector concept and R&D
● Prroospeccts ((aand thhee CCanaadiiaan cconnnecctiionn)
Proposed SuperB siite at Tor Vergata Roma II campus (near Frascatii, Itally)
Feb 26, 2009 TheS uSpuepreBrB ExperimeSntteven RobSetretvseonn R o b e Irntssotint,u tIen ostfi tPuatret iocfl eP Parhtyicsliec sPhysics 2 TThhee SSuuppeerrBB PPrroojjeecctt
SuperB is a 1036 luminosity e+e- asymmetric energy collider (7 GeV on 4 GeV at the ϒ(4S) resonance) with the capability to operate from charm threshold to the ϒ(5S)
● Proposed to be hosted by the INFN - Laboratori Nazionali di Frascati (LNF) in Italy Accelerator concept based on an ultra low emittance design exploiting the ILC damping ring lattice and ILC final focus
● Comparatively low beam currents and clean experimental environment ● Reuse of (essentially all) PEP-II magnets and RF Detector concept based on extensive reuse of BABAR experiment components, including software where appropriate ⇒ Target data sample: 75ab-1 O(100) times present world BB data sample
Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 3 ee++ee-- ccoolllliiddeerrss
Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 4 FFllaavvoouurr PPhhyyssiiccss ((iinn aa nnuuttsshheellll))
2 “types”, 3 “generations”
Only the weak interaction can tell them apart, and moreover, can change them into something else! This is somehow all related to the elusive The Standard Model Higgs boson (via Yukawa couplings) (according to Wikipedia)
Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 5 FFllaavvoouurr PPhhyyssiiccss ((ggrraadd sscchhooooll vveerrssiioonn))
Flavour physics: weak interaction couplings of quarks with universal coupling, but modified by the (non-diagonal) CKM matrix
● Parameterize the couplings between the three quark generations ● Weak eigenstates are essentially “rotated” in flavour space relative to mass eigenstates (i.e. physical quark states) d * π V ud u Vud Vus Vub b Vcb V = Vcd Vcs Vcb c Β+ D0 Vtd Vts Vtb u u CKM matrix can (and does) have complex entries:
● “Matter” and “antimatter” decays can differ (CP violation) ● Unitarity of V implies relationships between various matrix elements:
Vud Vub* + Vcd Vcb* + Vtd Vtb* = 0
Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 6 WWhhyy FFllaavvoouurr??
Flavour sector contains 20 (22) of 25 (27) parameters of the SM, which are intrinsically connected to EW physics and symmetry breaking
● Tantalizing structure (similarly for lepton sector) which is not predicted by the SM:
B0 → π+π− B0 → ρ+ρ− b → ulν B0B0 mixing Regardless of whether observable * b V u α td V non-SM physics exists at the TeV V * d tb scale, CKM structure hints that V u there is something important that * γ VcdVcb β we don't understand 0 * B → D π B → ψKS
+ 0 + B → D CP K b → clν B → φKS
Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 7 NNeeww PPhhyyssiiccss??
Several arguments suggest that the Standard Model is a low-energy approximation (effective theory) of a larger theory
● Quantum stabilization of the weak scale suggests ● Justification for building the LHC! Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 8 EEffffeeccttiivvee tthheeoorryy aapppprrooaacchh Effective flavour-violating couplings In explicit models: New Physics scale ● Λ ~ mass of virtual particles (e.g. Fermi theory: mW) ● C ~ (loop coupling) x (flavour coupling) Increasing (e.g. SM/MFV: αw x CKM) luminosity Precision flavour measurements provide bounds on ratio C / Λ i.e. constrain coupling strengths at any given mass scale Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 9 PPrreesseenntt FFllaavvoouurr CCoonnssttrraaiinnttss E.g. Model independent parameterization of New Physics NP SM contributions to B mixing amplitudes: 2iφ d QΔB2 QΔB2 Cqe SM QΔB2 Sensitivity ~200GeV Combination of CP violation, mixing and other flavour observables 1034 luminosity gives measurable effects if New Physics is at the Electroweak scale BABAR/Belle purpose: “test SM mechanism for CP violation” Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 10 22000088 NNoobbeell PPrriizzee "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature" Makoto Kobayashi, CP KEK, Tsukuba, Japan Toshihide Maskawa, YITP, Kyoto University, and Kyoto Sangyo University, Japan “It is only in recent years that scientists have come to fully confirm the explanations that Kobayashi and Maskawa made in 1972. It is for this work that they are now awarded the Nobel Prize in Physics. They explained broken symmetry within the framework of the Standard Model, but required that the Model be extended to three families of quarks... As late as 2001, the two particle detectors BaBar at Stanford, USA and Belle at Tsukuba, Japan, both detected broken symmetries independently of each other. The results were exactly as Kobayashi and Maskawa had predicted almost three decades earlier.” Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 11 PPrreesseenntt FFllaavvoouurr CCoonnssttrraaiinnttss E.g. Model independent parameterization of New Physics NP SM contributions to B mixing amplitudes: 2iφ d QΔB2 QΔB2 Cqe SM QΔB2 Sensitivity ~200GeV 1034 luminosity gives measurable effects if New Physics is at the Electroweak scale BABAR/Belle purpose: “test SM mechanism for CP violation” Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 12 SSuuppeerrBB SSeennssiittiivviittyy E.g. Model independent parameterization of New Physics NP SM contributions to B mixing amplitudes: 2iφ d QΔB2 QΔB2 Cqe SM QΔB2 SuperB Sensitivity ~1TeV 1036 luminosity gives measurable effects if New Physics is at the TeV scale SuperB purpose: search for and study New Physics effects in flavour Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 13 SSuuppeerrBB SSeennssiittiivviittyy Using Standard Model values Using current central values of CKM measurements: of CKM measurements: ? 1036 luminosity gives measurable effects if New Physics is at the TeV scale Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 14 TToowwaarrddss aa nnoo--lloossee tthheeoorruumm...... Assuming the LHC observes New Physics: ● Study flavour structure of New Physics using precision flavour studies 2 2 2 m11 m12 m13 2 2 2 2 mq m m m q ij 21 22 23 qi j q qi j 2 2 2 2 m31 m32 m33 (mq )23(13) Squark/slepton mass matrix sensitive to SUSY breaking mechanism, hence complementary information helps to clarify the New Physics scenario If the LHC does not (immediately) observe New Physics: ● Precision flavour studies may point to NP scale δbq ● Might even provide first observation of identifiable NP Λeff Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 15 a r X i v : 0 7 0 9 . 0 4 5 49 authors 1 ~24 institutions [ h e p - e x ] 3 Chapters : Physics Case Detector ● Significant contributions by the Machine Canadian community to both the 320 signatures 444 pages physics case and the detector ~80 institutions description Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 16 IInntteerrnnaattiioonnaall RReevviieeww CCoommmmiitttteeee External review of SuperB proposal requested by INFN to evaluate all aspects of the project (accelerator, detector and physics reach) ● Initial report released in early 2008: Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 17 RReecceenntt nneewwss In December 2008, the INFN formally approved SuperB as a “Special Project” with 3-year funding for work towards a Technical Design Report ● additional funding directly from Lazio regional government Project is currently under review by the CERN Strategy Group to evaluate the relevance of SuperB within the European context ● Recommendation expected this spring, but initial feedback has all been positive Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 18 SSuuppeerrBB PPhhyyssiiccss RReeaacchh SuperB physics case explored in detail in a series of workshops leading up to the Conceptual Design Report ● Rich program of B, charm and τ physics, plus additionally exotic states and spectroscopy The Discovery Potential of a Super B Factory (Slac-R-709, hep-ph/0503261) Physics at Super B Factory (hep-ex/0406071) Complementarity with LHC has been studied in the CERN workshop Flavour Physics in the era of LHC . (M.Mangano,T.Hurth to be published soon as CERN yellow report) Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 19 B Physics @ U(4S) Charm mixing and CP violation Charm FCNC τ Physics Bs Physics @ U(5S) Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 20 NNeeww PPhhyyssiiccss ssiiggnnaattuurreess (2003 SLAC Super B Factory Workshop Proceedings) Super symmetry Large Extra Dimension models - Different patterns of deviations from the SM predictions - Correlations with other physics observables. Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 21 LLHHCC BBeenncchhmmaarrkk SScceennaarriiooss Snowmass points mSUGRA benchmark points for LHC - No flavour structure defined (MFV) SPS4 is already ruled out by present values of Βsγ. SPS1a is the least favorable for flavour, but SuperB and only SuperB can observe ~2σ deviations in several observables Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 22 NNPP iinn ssiinn22ββ iinn ““ss--ppeenngguuiinnss”” Many channels can be measured with ΔS~(0.01-0.04) W b s ϕ SuperB t B0 s d s d d K0 ~g ~ ~ b b s s d 23 δ LR (*) theoretical limited Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 23 HHooww mmuucchh ddaattaa iiss ttoooo mmuucchh?? Determination of coupling [in this case : (δ13)LL] with 10 ab-1 and 75 ab-1 L L L L ) ) 3 3 1 1 δ δ ( ( m m I I SM SM Re (δ13)LL Re (δ13)LL Importance of having very large sample >75ab-1 Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 24 ττ LLeeppttoonn FFllaavvoouurr VViioollaattiioonn LFV from CKM Lepton MFV GUT models LFV from PMNS SO(10) MSSM 1 LFV from CKM 0 7 B LFV from PMNS R ( τ SuperB µ γ Very important order of magnitude 10-8 10-9 Complementarity with µ e γ M 1/2 MEG sensitivity µeγ ~10-13 LFV 5σ disc Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 25 SSuuppeerrBB AAcccceelleerraattoorr PPaarraammeetteerrss Asymmetric beam energies, luminosity upgradable to > 2 x 1036 Design includes longitudinal polarization for e- beam Beam currents below 2A for luminosity up to 2x1036 cm-2s-1 Ultra low emittance lattice: inspired by ILC Damping Rings Horizontal crossing angle and crab waist scheme minimize beam blow-up and maximize luminosity Total ring power is lower than PEP-II Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 26 LLaattttiiccee llaayyoouutt aanndd PPEEPP--IIII rreeuussee L (m) 0.45 5.4 Total length 1800 m mag m Dipoles PEP HER - 194 20 PEP LER 194 - Available SBF HER - 130 Needed SBF LER 224 18 SBF Total 224 148 Quad. Needed 30 0 Lmag (m) 0.56 0.73 0.43 0.7 0.4 PEP HER 202 82 - - - PEP LER - - 353 - - SBF HER 165 108 - 2 2 SBF LER 88 108 165 2 2 280 m SBF Total 253 216 165 4 4 Needed 51* 134 0 4 4 ● All PEP-II magnets are used, dimensions and fields are in range, ● RF requirements are met by the present PEP-II RF system Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 27 CCrraabb WWaaiisstt CCoonncceepptt Large crossing-angle scheme eliminates parasitic bunch crossings, but introduces beam-beam betatron coupling resonances Crab sextupoles Courtesy of OFF E. Paloni waist line is orthogonal to the axis of one bunch Crab sextupoles ON waist moves to the axis of other beam All particles from both beams collide in the minimum βy region, with a net luminosity gain Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 28 DDAAΦΦNNEE CCrraabb WWaaiisstt TTeesstt Tests of the crab waist concept were recently performed at LNF for the DAΦNE accelerator upgrade ● Crab sextupoles are working nicely and results are in good agreement with simulation: e t a r a h b a h B d e r u s a https e ://agenda.infn.it/materialDisplay.py?materialId=0&confId=501 M Crab sextupoles off Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 29 PPrrooppoosseedd SSiittee Tor Vergata site located on the Roma II university campus near the Frascati laboratory ● Green-field site, but civil construction and infrastructure support anticipated for SPARX FEL project beginning this year ● Seismic and geological studies complete ● Interest (and funding support) from regional government ● Strong support from INFN Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 30 TToorr VVeerrggaattaa SSiittee SPARX SuperB Ring (about 1800m) SuperB Injector (about 400m) Roman Villa 100m SuperB Main Building Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 31 EExxppeerriimmeennttaall AArreeaa Initial concept for layout of SuperB experimental area now available ● civil construction could begin as soon as next year: significant cost savings if coupled to SPARX construction Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 32 SSuuppeerrBB DDeetteeccttoorr Detector concept based on reuse of BABAR components with replacement/upgrades to ensure “SuperB” physics performance DIRC CsI(Tl) barrel quartz calorimeter and bars support structure Super- Muon conducting system solenoid iron/flux return (?) Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 33 SSuuppeerrBB DDeetteeccttoorr Detector concept based on reuse of BABAR components with replacement/upgrades to ensure “SuperB” physics performance Silicon L(Y)SO crystal pixel forward endcap vertex calorimeter tracker Backward Forward endcap PID calorimeter Compact Improved DIRC muon readout detector Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 34 SSiilliiccoonn VVeerrtteexx DDeetteeccttoorr Reduced boost (compared with BABAR) requires improved vertex resolution to obtain same performance ● Small beampipe (1.5cm radius), better single-hit resolution Basic R&D for CMOS MAPS in progress (most challenging option for first detector layer): ● Optimization of the Deep NWell MAPS pixel S/N ~ 25 with low power consumption APSEL4D - Fe55 5.9 keV calibration peak APSEL4D - 32x128 pixels 50 µm pixel pitch APSEL4D – Sr90 test Fired pixel map with threshodl @ ½ MIP Good uniformity (the source was positioned on the left Preliminary test encouraging: side of the matrix Good sensitivity to e- from Sr90 and Fe55 source Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 35 TTrraacckkiinngg ((DDrriifftt CChhaammbbeerr)) Charged particle tracking using a small-cell drift chamber based on BABAR design: Lighter structure, all in carbon fibre ● Spherical (convex) carbon fibre end-plates ● Thickness ~4mm, or 0.015 X0 (0.13 X0 in BABAR) Improved front end electronic (faster, less material) ● place detectors (e.g. forward PID device) behind the DCH backward endplate High background rates expected in the forward region ● high occupancy in innermost cell layers ● taper endplates or screen sense wires? Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 36 PPaarrttiiccllee IIddeennttiiffiiccaattiioonn Ability to distinguish charged kaons from pions is critical for any sort of flavour - physics studies ● Main particle identification system is BABAR DIRC (ring imaging Cherenkov device based on quartz radiators) reduce size and improve add PID coverage in forward robustness of readout system direction (TOF) Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 37 DDIIRRCC ssyysstteemm DIRC must image (partial) rings of photons produced in the quartz bars above a high background of random photons from beam backgrounds ● Initial tests of various possible configurations recently performed: s short 2 pixels together? Hamamatsu H-8500 MaPMT (64 pixels, 6x6mm pad, σ ~140ps) ns Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 38 TTOOFF ffoorr ffoorrwwaarrdd PPIIDD Recent testbeam performed at Fermilab on Time of Flight (TOF) prototype with two identical detectors Photonis MCP-PMT with 10µm holes, 64 pixels Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 39 CCaalloorriimmeetteerr CsI(Tl) barrel EM calorimeter can be retained in SuperB with minor modifications but the forward endcap must be replaced ● LYSO (lutetium yttrium orthosilicate): Faster decay time, smaller Molière radius, shorter radiation length, radiation hard ● More compact crystals, leaving space for forward PID system Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 40 LL((YY))SSOO LSO / LYSO CMS APD readout module 2 @ 5mmx5mm APD Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 41 FFoorrwwaarrdd eennddccaapp llaayyoouutt Several possible configurations for endcap crystal layout (cartesian, fully pointing etc) ● Geant4 full simulation of crystal geometry and dead materials ● Aim for initial beam tests of endcap prototype (5x5 or 7x7 array) by 2010 Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 42 RReeaarr EEnnddccaapp CCaalloorriimmeetteerr Rear calorimetry needed to improve detector hermeticity for inclusive/missing energy studies ● resolution doesn't have to be great, but need at least “veto” capability ● severe space constraints from DCH electronics and DIRC readout system Pb/scintillating tile device using SiPM readout, built as two D's to fit within the DIRC tunnel ● 12 X0, with 0.5 X0 sampling ● Energy resolution ~15%/E (GeV) Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 43 RReeaarr EEnnddccaapp CCaalloorriimmeetteerr Based on hadronic calorimeter concept for the International Linear Collider project (CALICE) ● Silicon photomultiplier readout from imbedded fibres: Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 44 IIFFRR ((mmuuoonn ssyysstteemm)) Concept : Minos-style extruded scintillator interleaved with iron plates (solenoid magnetic flux return) s t n u Distance ~200 cm Distance o ● Readout with Geiger mode APDs c sigma 1.3 ns ~200 cm sigma 1.8 ns (Hamamatsu or IRST-FBK) SiPM MPPC ● Average ~ 9 p.e. at maximum distance (~4m), efficiency better that 95% ● Preliminary detector layout for summer 2009 and prototype beam test planned for spring 2010 time resolution < 2 ns Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 45 PPrroossppeeccttss ● SSupppoorrt ffoorr tthhe SSuupeerB pproojjecct hhaas bbeeen ggrowiinngg raappiidllyy overr tthee ppasst ffeew yyeeaars:: - Physiics case iis solliid; strong support from theory communiity - Stiillll substantiiall challllenges for the accellerator, but no show- stoppers - Polliitiicall devellopments iin Itally, Europe and North Ameriica allll appear favourablle* ● SSiignniifiiccaannt CCaannaadiiaan iinnvoollveemeenntt rreeceentlly iinn tthee SSuupeerrB pprojjeectt, iinn paartiiccuullar tthhee CCDRR aandd VValleencciia ddoocuumeenttss - Potentiiall for detector and accellerator R&D over next few years ⇒ FFiirrsstt CCaannaaddiiaann pprroojjeecctt ggrraanntt rreeqquueesstt ssuubbmmiitttteedd tthhiiss ffaallll WWoorkiing too bbuiilldd aa CCaannaadiiaan SSupperBB coommmuuniittyy Feb 26, 2009 TheS uSpuepreBrB ExperimeSntteven RobSetretvseonn R o b e Irntssotint,u tIen ostfi tPuatret iocfl eP Parhtyicsliec sPhysics 46 BBaacckkuupp sslliiddeess Feb 26, 2009 SuperB Steven Robertson Institute of Particle Physics 47