Aurelio Bay Institut de Physique des Hautes Energies

1. July 13-25, 2000, Hanoi, Vietnam Aurelio Bay Institut de Physique des Hautes Energies Aurelio.bay@iphe.unil.ch

2. t b d from Dm: (1-r)2+h2 W W t d b ~ (1-r)2 + h2 SM Im r2+h2 from BÆXu+ln B0 J/Y Ks ~Vtd B0 t ~Vub W W t B0 b g Re CP Asym ~ sin[2(b+fnew )] The Unitary Triangle

3. b d NEW FCNC + d b ~ (1-r)2 + h2 b+fnew NEW + New FCNC from Dm: (1-r)2+h2 + rnew + + rnew r2+h2 = cte from BÆXu+ln Unchanged B0 t W t b+fnew

4. t b d W W t d b b d NEW FCNC + d b ~ (1-r)2 + h2 NEW SM + New FCNC from Dm: (1-r)2+h2 +rnew Im + rnew r2+h2 from BÆXu+ln B0 J/Y Ks Unchanged B0 ~Vub t W W t B0 g b+fnew Re CP Asym ~ sin(2(b+fnew)) The Unitary Triangle

5. CP in BÆJ/Y Ks ~ 2(b +fnew) Bd ÆD*+ np vs Bd ÆD*+ np Bd ÆD*- np vs Bd ÆD*- np g from Bd ÆD*-np+, D*+np-, etc. 2(b + fnew) + g From g Idem with Bs decays: compare the two g determinations (then combine them) 2 ( dg + fsnew) from CP in BsÆJ/y f 2 ( dg + fsnew) - gfrom CP in BsÆDs-K+, Ds+K- g We want to measure g, we need to select hadronic decay channels, we want to study the Bs system, have K/p separation, access to Br < 10-7….

6. BABAR, BELLE, CLEO-III, CDF, D0, HERA-B will test CKM at the O(l3) level. LHCb is a second generation experiment for CP violation studies in the B and Bs meson systems. The goal is to obtain precise and overconstrained determination of CKM elements, including terms beyond O(l3). This will permit to detect deviations from the Standard Model description and thus to probe New Physics. Second generation means: High statistics is needed to study Bu,d,s decays with Br < 10-7 Excellent proper time resolution Excellent particle identification Efficient and flexible triggering scheme, including a selection on hadrons. High statistics can be obtained by LHCb because B production cross section at 14 TeV: LHCb running luminosity: fi LHCb overlook sbb ≈ 500 mb 2 1032 cm-2 s-1 Rate(bb) = 105 sec-1 : 0.5% total inelastic

7. q Π[15, 300]mrad h Π[4.9, 1.9] Magnet dipole LHC beams collide here x z 20 m 10 m LHCb non-bending plane view Vertex Locator Open geometry with (quite) easy access to (almost) all components

8. LHCb bending plane

9. s impact parameter toward spectrometer [mm] 100 80 cm 10 retract by 3 cm during beam setup 0.1 1 10 0 Pt [GeV] -20 0 0.8 4 cm Vertex Locator (VELO) Z sz ≈ 40 mm resolution on interaction point • ≈ 200 mm Si single-side • R and f measuring planes • 220 kchannels, analogue R/O, S/N =15 Design work on front-end chip (DMILL and sub-micron technolgies) in progress prototype of R measuring 1/2 plane

10. pixel HPD Gas C4F10 Aerogel Gas CF4 0 large aerogel rings small C4F10 CF4 rings RICH K–pseparation > 3s 1<p< 100 GeV/c

11. 1 p.e. pedestal 2 p.e. 3 p.e. 4 p.e. Pion beam: large rings in aerogel and small rings in C4F10 RICH R&D • Photodetectors options: • HPDs and multianode PMTs • single photoelectron resolution • QE = 17% @ 400 nm • spatial resolution ~1 mm • large area ~2.9 m2, active: ~ 70% • Æ 325 kchan. binary readout • B stray field up to 100 gauss • radiation dose < 3kRad/year threshold DEP prototype pixel HPD

12. sp/p = 0.3 % [5 , 200] GeV/c s(MB->pp) =15 MeV/c2 s(MD->KKp) = 4 MeV/c2 Other Systems • Magnet: Warm dipole 4 Tm - 4.2 MW - 1450t TDR ok • Tracker Inner: (40x60 cm2) triple GEM , Si 3 stations Outer: straw-tube drift chambers • Calorimeter (design completed) Pre-shower sandwich Pb - scintillators ECAL Shashlik type, 25 X0 HCAL Fe + scintillating tiles, 5.6l R/O by wave-length shifting fibers and PMTs • MUON Resistive Plate Chambers (RPC) + Wire and Cathode Pad Chambers (WPC/CPC) for high rate regions

13. Joint Calorimeter Test 0 20 40 GeV 30 ECAL Shashlik HCAL resolution % 20 10 HCAL Fe+scintillating tiles 0 0 50 100 150 200 GeV preshower ECAL resolution %

14. LHCb Trigger Efficiency for reconstructed and correctly tagged events L0(%) L1(%) L2(%) Total(%)  e h all BdJ/(ee)KS + tag 17 63 17 72 42 81 24 BdJ/()KS + tag 87 6 16 88 50 81 36 BsDsK + tag 15 9 4554 56 92 28 BdDK      Bd + tag 14 8 7076 48 83 30 where the lepton trigger is important where the hadron trigger is important Tags considered (so far): • muon or electron from other b-hadronb Æ lepton • charged kaon from other b-hadronb Æ c Æ s Overall tag efficiency = 40% Overall mistag rate = 30%

15. hadron trigger threshold Trigger System LHC: 40 MHz L0:1 MHz L1:40 KHz Output:200 Hz High PT muons Latency: 4 ms < 2 ms L1 Trigger 3D reconstruction of secondary vertices L0 decision unit L2+L3 Trigger Full event information High PT electrons High PT hadrons Pileup Veto B0Æp+ p- Running luminosity 2 x 1032 Inelastic pp interactions ~30 % ~10%

16. DsK Bs-Bs oscillations with BsDs Measurements of ms with a significance >5: up to psxs Ds Dms= 30 ps-1 5.2 5.3 5.4 5.5 GeV/c2 Mass, decay time resolutions and particle ID  without RICH with RICH Bs DsK separation from Bs Ds Mass(DsK) sm = 11 MeV/c2 Ds DsK 5.2 5.3 5.4 5.5 5.6 GeV/c2

17. LHCb CP Sensitivities in 1 year Parameter Channels+c.c. No of events (1 year)  Bd 5k @P/T = 30°, |P/T|=0.200.02, =90° 2-5 Bd0  r  1k @=50° 5 2+ Bd  D*(incl.) 260k @2+=0 12  BdJ/Ks 100k <0.6 -2 Bs DsK 2400 8(Dms=15ps-1) - 12  (45ps-1)  Bd  DK* 400 10  Bs  J/ 50k 0.6 Bs oscillations xs Bs  Ds 35k up to 75 (5s) Rare Decays Bs   11 s/b=3.5 Bd K0*  4500 s/b=16 Bd  K*  26k s/b=1 See yellow Book CERN 2000-004 !

18. Magnet 1999LHCbapproved 1998 TechnicalProposal Detector and DAQ installation Magnet installation LHCb schedule (and conclusion) 2000 RICH, Calorimeters Outer Tracker Technical Design Reports Muon System 2001 Vertex Detector Inner Tracker L0 & L1 Trigger, DAQ 2002 Computing 2003 2004 2005 LHCb ready for LHC « day one » and for many years of B physics at “nominal LHCb luminosity”