B s and Λ b Lifetimes and BRs at the Tevatron Satyajit Behari (For the CDF Collab.) Johns Hopkins Univ., Baltimore,USA 25 th September 2006 Beauty 2006, University of Oxford, UK

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Contents Introduction Lifetime Measurements Motivation Λ b lifetimes (Λ b  J/Ψ Λ) B s lifetimes Flavor specific  (B s  D s ℓ )  (B s  D s , D s    ) ΔΓ CP /Γ CP in  L (B s  K + K - ) ΔΓ CP /Γ in BR(B s  D s ( * ) D s ( * ) ) Summary BR Measurements BR(B s  D s ( * ) D s ( * ) ) BR(B s  D s1 (2536)  X) BR(B s  D s D s ) / BR(D s D + ) BR(Bs    ) limits Talk by Cheng-Ju Lin [ Talk by Cheng-Ju Lin ] ΔΓ in Bs  J/Ψ  Talk by Avdhesh Chandra [ Talk by Avdhesh Chandra ] Other talks:

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep The Tevatron Main Injector & Recycler Tevatron Chicago   p source Booster pp p p pp 1.96 TeV CDF DØ

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep CDF and DØ Detectors in Run 2 Both detectors Silicon microvertex tracker Solenoid High rate trigger/DAQ Calorimeters and muons Good electron, muon ID and acceptance Excellent tracking acceptance |  | < 2-3 L2 trigger on displaced vertices Excellent tracking resolution Good low momentum PID

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep B Production at Tevatron Since  (bb) <<  (pp)  Events have to be selected with specific triggers Trigger requirements: large bandwidth, background suppression, deadtimeless Flavor Creation (annihilation) qb q b Flavor Creation (gluon fusion) b g g b Flavor Excitation q q b g b Gluon Splitting b g g g b Tevatron is a source of all B-hadron species, B d, B u, B c, B s and Λ b  b = 29.4 ± 0.6 ± 6.2  b (|η| < 1) ( CDF ) Huge cross-sections compared to the the B-factories but proportionally large backgrounds as well

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Triggers for B Physics CDFDØ Single-/Di-lepton ( CDF/DØ ) A high p T lepton or two leptons with lower p T J/Ψ modes, masses, lifetimes, x-section Yields higher than Run I (low Pt threshold, increased acceptance) CDF lepton + displaced track - semileptonic sample (CDF) p T (e/  ) > 4 GeV/c, 120  m 2 GeV/c Semileptonic decays, lifetimes, flavor tagging B Yields 3x Run I CDF Two displaced vertex tracks - hadronic sample (CDF) p T (Trk) >2 GeV/c, 120  m 5.5 GeV/c X-section, branching ratios, B s mixing… Primary vertex Secondary vertex Impact parameter ~ 1 mm b decays

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Interests in B Hadron Lifetimes Test of non-spectator effects in decays of heavy hadrons which give rise to lifetime hierarchy: ≥≈>»  (B + ) ≥  (B 0 ) ≈  (B s 0 ) >  (Λ b ) »  (B c ) HQE Heavy Quark Expansion includes these effects (expansion in 1/m b ) and predicts lifetime ratios:  (B + )/  (B 0 ) = 1.00 ± 0.05 x (f B /200 MeV) 2  (B s 0 )/  (B 0 ) = 1.00 ± 0.01  (Λ b )/  (B 0 ) ~ 0.9 The B+,B0 lifetimes are precisely measured at B-factories. Λ b and B s 0 ratios are unique to Tevatron. EXPERIMENT THEORY (NLO) C. Tarantino, hep-ph/

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep B s Lifetime Difference B s has a large branching fraction to CP eigenstates Dominated by b  ccs transition: Bs  Ds (*)+ Ds (*)- (Bd: b  ccd Cabibbo suppressed, 20x smaller) Ways to measure: Compare  (B s  CP even) to  (B s  CP mixed or CP odd) Angular analysis of B s  J/   separates CP even and CP odd. [ See the talk by Avdhesh Chandra ] Indirect: Measure Br (B s  D s ( * )+ D s ( * )- ),  L (Bs  K + K - ) SM prediction:  s /  s =  L -  H = (9.3 ± 4.6) % ( Beneke et al ) World average:  s /  s = (SLD, LEP, CDF I results +  (B s )=  (B d ) constraint) ( < 0.29 at 95% CL) hep-ph/

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Λ b Lifetimes

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Λ b Lifetime in Λ b  J/Ψ Λ 1 fb -1 data 174 ± 21 Λ b events Extract lifetime by an unbinned maximum likelihood fit to mass and proper decay length. Major source of systematic is contamination from B 0 Using B 0  J/Ψ K s 0 lifetime:

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Λ b Lifetime in Λ b  J/Ψ Λ 1 fb -1 data 538 ± 38 Λ b events Major sources of systematics are due to modeling of ct resolution and V 0 pointing Using world average B 0  J/Ψ K s 0 lifetime: World best measurement!

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Λ b Lifetime – Measurement vs Theory The world average on  (Λ b )/  (B 0 ) measurements used to show ~2σ lower value than the NLO prediction so far. The new result sits above the prediction! Need more experimental inputs to conclude the issue. Looking forward to  (Λ b ) in fully hadronic decay modes, e.g. Λ b  Λ c   (Λ b )/  (B 0 )

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep B s Lifetime Differences

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep pb pb -1 B s Lifetime  (B s  D s ℓ  X) World’s best result!

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep B s Lifetime  (B s  D s , 3  ) Fully reconstructed hadronic decays from displaced track trigger 360 pb -1 in CDF Run 2. Trigger bias is removed by a Monte Carlo approach. Mass and decay length fitted simultaneously to extract lifetime. Would be updated for 1 fb -1

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep ΔΓ CP /Γ CP in  L (B s  K + K - ) Measure  L (95% CP even state) 360 pb -1 data from displaced track trigger Four h + h - components are resolved by mass, kinematics and PID info. B d lifetime is fixed to world average Dominant systematics from dE/dx based PID, MC p T input spectrum Extract ΔΓ CP /Γ CP using flavor specific  (B s 0 ) from other measurements.

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep ΔΓ CP /Γ CP in BR(B s  D s ( * ) D s ( * ) ) 1 fb -1 sample D s  , D s         Start with  D s sample (D s   ), look for additional  D s  sample  Ratio of efficiencies estimated using simulated events. Directly fit D s mass distribution to extract N(  D s ). Unbinned likelihood to extract N(  D s ) (Lower statistics)  D s  =  310  D s  = 19.3  7.9 Dominant sources of systematics: BR(Bs   D s (*) ) MC p T reweighting

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Tevatron ΔΓ CP /Γ CP Summary

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep B s Branching Fractions

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Bs  D s1 (  )  X Bs  Ds**  D* K S D0   K  c+s quark in L=1 state : Provide test HQET A significant fraction of semileptonic decays : Compare exclusive/inclusive decay rates Extract CKM matrix elements An additional channel for Bs mixing. Need to develop more understanding in the light of discoveries which don’t agree with predictions : DsJ(2317), DsJ(2460), DsJ(2632) – SELEX and so on…

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Bs  D s1 (  )  X(Contd..) N = 42.6  8.6 ~ 5  BR(B s ->D s1  X ) = 0.86  0.16  0.13  0.09 (%) ISGW2 0.53%, IQM 0.39%, HQET&QCD Sum rules 0.20% Comparison with theory

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep BR(B s  D s D s ) / BR(B 0  D s D - ) fs/fd * BR(Bs → DsDs ) / BR(B0 → DsD+) = 0.43 ± 0.11(Stat) ± 0.03(Syst) ± 0.10(BR) BR(Bs → DsDs ) / BR(B0 → DsD+ ) = 1.67 ± 0.41(Stat) ± 0.12(Syst) ± 0.24 (fs/fd) ± 0.39(BR) 5.8σ Observation!

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Summary With over 1 fb -1 accumulated data / experiment and much more to come, heavy flavor physics at Tevatron is entering a precision era. Using large B s and Λ b samples, unique to Tevatron, various theoretical predictions are put to stringent tests. Many world best measurements have been made. Lifetimes in fully hadronic Λ b decays are underway. Other excited baryonic modes to follow. Check out more Tevatron B physics results: CDF: CDF: DØ: DØ:

S.Behari, Bs / Lb Lifetime and BRs at the Tevatron, Beauty th Sep Backup-1 ΔΓ CP /Γ CP in BR(B s  D s ( * ) D s ( * ) ) Background processes: