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M.N MinardAspen Winter Meeting 20091 LHCb Physics Program On behalf of LHCb collaboration M.N Minard (LAPP) Status LHCb ( R.Jacobson) Single arm spectrometer.

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Presentation on theme: "M.N MinardAspen Winter Meeting 20091 LHCb Physics Program On behalf of LHCb collaboration M.N Minard (LAPP) Status LHCb ( R.Jacobson) Single arm spectrometer."— Presentation transcript:

1 M.N MinardAspen Winter Meeting 20091 LHCb Physics Program On behalf of LHCb collaboration M.N Minard (LAPP) Status LHCb ( R.Jacobson) Single arm spectrometer B- physics dedicated

2 M.N MinardAspen Winter Meeting 20092 Improve precision on CKM parameters Impressive results from B factories & K sector Good agreement with SM Bs emerging Tevatron results Belle LHCb will contribute Strong constraints from SM on KM sector Direct  measurement :LHCb Indirect Direct measurement

3 M.N MinardAspen Winter Meeting 20093 LHCb hints for NP  Hints for NP contribution in loop processes as tree and box / penguin diagrams. NP from CPV domain precision measurements : Observe deviations from SM expectations Confront measurements between channels expecting different NP interference  s, mixing phase of the Bs system  measurements NP from rare decays high precision measurements : -Branching ratio -Time asymmetry measurements Oscillation box Strong penguinEW penguinRadiative penguin

4 M.N MinardAspen Winter Meeting 20094 LHCb apparatus characteristics High statistics on all b and c species : – 2fb -1 : 10 12 bb pairs –Heavy flavor precision experiment Lepton and hadron trigger (HLT) Efficient particle ID Decay time resolution Flavour tagging ε(K  K) : 97% ε(π  K) : 5% proper time resolution ~ 40 fs Bs  Ds(KKπ)K b tag BsBs KK KK    K   DsDs Primary vertex Bs→ Ds K Bs →Ds  B0-> J/  K0s Sensitivity: 236k events/2 fb -1  (sin  ) = 0.020 [B factories: 0.025 (850 fb1)]

5 M.N MinardAspen Winter Meeting 20095  B s mixing phase  s

6 M.N MinardAspen Winter Meeting 20096 B s phase  s NP may modify the mixing phase  s can be extracted from CP time-dependent asymmetry decay rates : with n f = ±1 CP eigenstate +NP? B0sB0s W s b c c s s B0sB0s B0sB0s tt W W b s b s Bs  J/Ψ η, Bs  J/Ψ η’, Bs  ηc Φ Bd  Ds+ Ds- CP eigenstate Bs -> J/Ψ , mixing +-1 CP eigenstate Lifetime B 0 s, B 0 s distributions give oscillation pattern of frequency  ms and amplitude ~ sin  s trough the phase in the mixing box diagram.  s =-2  s

7 M.N MinardAspen Winter Meeting 20097 B s phase  s (2) Use of pure CP eigenstates statistic limited B s -> J/Ψ  large yield, low background mixture of CP = +1 and CP = -1 states angular analysis to disentangle the two states Current results from Tevatron: D0  s =  0.57 + 0.24 -0.30 with 2.8 fb -1 CDF  s = [0.28,1.28] @ 68%CL with 2.8 fb -1  ( Δ  s /  s ) = 0.0092 With 10 fb-1  stat (  s )  0.009 > 3  for non-zero  s of SM SM  S (B s -> J/Ψ  ) = -2  s = -0.0368 ± 0.0017

8 M.N MinardAspen Winter Meeting 20098 The effects of New Physics in the oscillation can be parameterized as: arXiv:0810.3139 Room for NP in B s mixing

9 M.N MinardAspen Winter Meeting 20099 b  sss hadronic penguin decays B s   In SM CP violation < 1% due to cancellation of the mixing and penguin phase:  Bs   SM  2 arg(V ts * V tb ) – arg(V ts V tb * ) = 0 In presence of NP expect different contributions in boxes and in penguins :  Bs   NP =  Mixing NP -  Decay NP + NP? Mixing CP asymmetry angular analysis & time dependance of flavour tagged events For 2 fb –1  stat (  SM ) = 0.11 B d related quark penguin B d   K S & B d  J/  K S expected precision:  (sin(2  eff )) ≈0.23 ChannelYield (2 fb -1 )B/S (90%CL) B s   3100< 0.8 B d   K S 920< 1.1 + NP? V tb Mixing box V ts

10 M.N MinardAspen Winter Meeting 200910  related measurements

11 M.N MinardAspen Winter Meeting 200911  s +  from B s  D s K 2 Trees : b->c & b->u interfere through B s mixing Measure  s +  Ratio extracted from data Include B s  D s  to constrain  m s Fit time-dependent rates of B s →D s K and B s →D s   s +  9  -12  msms 0.007 ps -1 Sensitivity with 2fb –1 : ChannelYield (2 fb -1 )B/S (90%CL) B s  D s K6200< 0.2 Bs  Ds Bs  Ds  140 k0.4 B s → D s -   B s → D s - K +  -K id

12 M.N MinardAspen Winter Meeting 200912  from trees: B  DK Two tree amplitudes (b  c & b  u) interfere in decays to a common D 0 and D 0 state f D Exploit interference according the decay mode ( analysis from B-factories).  GLW : CP eigenstate  f D (*)0 D0-> K + K - /  +  -, Ks  0  ADS : Use common flavor state - doubly cabbibo supressed D 0- > K+  - Lower event rate / large asymmetry - Favoured mode: Large event rate / tiny asymmetry  Dalitz for 3 body decays f D(K+  -) K – D0K–D0K– D0K–D0K– bcbc bubu B–B– f D(CP) K – f D(K-  +) K – _ For each mode parameters ,(r b,  b )

13 M.N MinardAspen Winter Meeting 200913  from loops: B 0 d/s  h + h - Interference of b  u tree & b  d(s) penguin diagrams leads to CP violation depending on  (Sensitive to NP) A dir & A mix depend on mixing phase 2 , , and ratio of penguin to tree amplitudes = d e i  B 0      and B s 0  K + K - (d->s) diagrams U-spin symmetry. 4observables: (A dir & A mix )   A dir & A mix ) kk – Parameters :  penguin to tree amplitudes (d e i    kk decayYield (2fb -1 ) B/S B0 B0  36k0.5 B s 0  K + K - 36k1.5 Compare to  from trees to get hints of NP in penguins NP

14 M.N MinardAspen Winter Meeting 200914  from trees: B  DK B modeD modeMethodYield (2fb-1) sensitivityParamete r B s →D s KKK  tagged, A CP (t) 6.2K  +2  s B + →D K + favo KK ADS56K 8.2 9.6 ° Strong phases  B + →D K + suppr KK ADS*  B + →D K + KK/  counting, GLW8.6k  B ±  D 0 K ± K3  ADS61K  B ±  D 0 *K ± D 0  0 /D 0  GLW +ADS42K  B ±  D 0 K ± K+K-K+K- GLW Dalitz1.718°  B 0  D 0 K* 0 K  KK,   ADS+GLW5K6-25  B→ ,KK  tagged, A CP (t)36K10  d  s HLT trigger K-  PID Mass resolution Global fit from ADS/GLW under  B °assumption =35° R b Combine tree – 2fb -1  (  ) : 4° tree

15 M.N MinardAspen Winter Meeting 200915 Rare decays

16 M.N MinardAspen Winter Meeting 200916 Rare decays seeking for NP BR(SM)BR exp @ LHCb  Z,       NP? in B s   polarization (57 +18 -12 +12 -11 ) 10 -6 Belle’08  C7 Bs+-Bs+- (3.35±0.32)·10 -9 helicity suppressed TeVatron @ 90% CL (2 fb -1 ) < 45  10 -9 BR S-P coupling B 0  K*  +  - (1.22 +0.38 -0.32 )·10 - 6 B factories angular distributions  C7,  C9 Large Theory Error On br «

17 M.N MinardAspen Winter Meeting 200917 B s    Helicity suppressed – NP sensitivity in SM: BR(B s →  ) (3.35 ± 0.32) x 10-9  Enhancement from SUSY model : BR(B s →  )  tan 6  /M H 2 Sensitive to new physics coupling with Scalar & pseudo scalar SM Ex: NUHM1 Ex : Possible enhancement BR(Bs   +  -)~20x10 -9 J.Ellis et al. arXiv:0709.0098v1 [hep-ph] (2007)

18 M.N MinardAspen Winter Meeting 200918 B s   Analysis relies on : Geometry Likelihood (GL) : geometrical properties ( muon IPS, B lifetime, isolation, IP) Good mass resolution Particle ID : DLL (  -  ) & DLL(  -K) - Sensitive Region: GL > 0.5 - Statistical method applied to separate signal from background SM BR, in 2fb -1  21 signal events  172 background events (arbitrary normalization) Major uncertainty on BR from relative B s,B  hadronization fractions  14%. Bs branching ratio determination useful (arbitrary normalization)

19 M.N MinardAspen Winter Meeting 200919 Within SM BR: 2 fb –1  3  evidence 10 fb –1  5  observation Expected CDF+D0 limit 8fb-1 B s   90% exclusion Main uncertainty hadronization fraction

20 M.N MinardAspen Winter Meeting 200920, Z 0 B0K0*+-B0K0*+- Suppressed Loop FCNC process (EW penguins) Several observables to test the dynamics –Afb (s=mll2) –Angular distributions:  l, ,  K* –Invariant mass  +  - s =(m  ) 2 =q 2 NP can affect: –Forward-backward asymmetry A FB (s) in  l distribution –Dependence on s (predicted by several models) Zero of A FB (s) SM s 0 =4.36 +0.33 -0.31 GeV 2 /c 4 NP M mm 2 (GeV 2 ) Afb Example 2 fb -1 experiment (LHCb @ 10 fb -1  (s0)=0.28)

21 M.N MinardAspen Winter Meeting 200921  polarization in B s   B s   FCNC radiative penguin Time dependent CP asymmetry probe SM/NP –SM= A dir  0, A mix  sin2  sin2 , A   cos 2  cos  fraction of wrongly polarized photon tan  = |b→s  R | / | b→s  L |~0 cos  1 Sensitivity ;  (Adir, Amix ) = 0.11  A  ) =0.22 for 2fb-1 SM extensions (left-right-symmetric, unconstrained MSSM) predict large tan  while no change on inclusive BR (b  s  )

22 M.N MinardAspen Winter Meeting 200922 Conclusions LHCb is looking forward for the 1st collisions Interesting results can comme early ( 0.5 fb -1 ) –Bs→ J/  s measurement with 0.05 precision –Bs ->  BR limit close SM value –Direct  measurement  (  ) 10° LHCb able to provide strong improvement in B s sector Channels variety allows field for indirect NP discovery

23 M.N MinardAspen Winter Meeting 200923 Backup

24 M.N MinardAspen Winter Meeting 200924 Physics from (very) first data 10 8 minimum bias @ 2kHz Exploit minimum bias data (almost no trigger) S= σ mb σ∙εσ∙ε ∙N mb Number of selected signal events:

25 M.N MinardAspen Winter Meeting 200925 Sensitivities for 100 fb -1 Also studying Lepton Flavour Violation in   

26 M.N MinardAspen Winter Meeting 200926 Upgrade Increase L0 hadron bandwidth Manage a factor 110 in luminosity –Go from 1Mhz to 40 Mhz data flow Implications : –Electronics and detector upgrade is being investigated –Change Vertex Locator to pixels 3D device

27 M.N MinardAspen Winter Meeting 200927 Rare decays In the SM, b  s only through loops (FCNC) implies: –Processes are rare –Powerful to find/constraint NP! Operator Product Expansion parametrize new physics effects through # b  s observables : Observables are functions ofC’s. –Branching ratios (BR) Cs –Polarizations (C9) –Angular distributions (C7/C9) Three examples for LHCb: B s   K  K   B 0  K*  K     +  - Bs +-Bs +-

28 M.N MinardAspen Winter Meeting 200928 Full 3D Angular Analysis

29 M.N MinardAspen Winter Meeting 200929

30 M.N MinardAspen Winter Meeting 200930 Charm Physics Sensitivity to NP : loop diagrams involves d quarks Mixing Mixing observed in Babar & Belle x = 0.89± 0.26% y = 0.75± 0.17%. Time-dependent D0 mixing with wrong-sign D0  K+  – decays. Direct CP violation in D0  K+K–

31 M.N MinardAspen Winter Meeting 200931 With luminosity increase level of interest emerge: 0.5 fb-1 Bs→ J/  precision on  s Bs ->  improved limit 2 fb -1 (1year) CPV  from tree : 5  from penguins 10 Bs mixing phase  : 0.023  s eff from penguins : 0.11 Rare decays s 0 0.5 GeV 2 from B  K *   Bs ->  6 10 -9 at 5  10fb-1 CPV  from tree & loop : 4  from penguins : 6 Bs mixing phase : 0.009 MS level Rare decays s0 0.3 GeV 2 from B  K*  Bs ->  SM at 5  Bs->  (A  ) =0.09

32 M.N MinardAspen Winter Meeting 200932 Room for NP in B s mixing 2006 including  m s measurement With  s from B s  J/  LHCb 2fb -1 Ligeti, Paucci,Perez, hep-ph/0604112 New Physics in B s mixing amplitude M 12 parameterized with h s and  s : Additional constraints can come from semileptonic Asymmetry. In SM: A SL s  10 -5:. B s  D s  hshs ss LHCb expects  10 9 events/ 2fb -1   (A SL s ) stat  2x10 -3 in 2fb -1 A SL s hshs


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