Measurement of mixing and the CPV phase φs in the B s system at LHCb

• Using 1 fb^-1, i.e. 21.2k B_s → J/ψ phi(KK), • φ_s = -0.001 ± 0.101(stat) ± 0.027 (sys) rad • ΔΓs = 0.116 ± 0.018 (stat) ± 0.006 (sys) ps^-1 • Γ_s = 0.658 ± 0.005 (stat) ± 0.007 (sys) ps^-1 • With 0.37 fb^-1, using B_s →J/ψKK the two-fold ambiguity is resolved • The 'proper' solution is the one with ΔΓ_s > 0 and φ_s ∼ 0 • With 1 fb^-1, the resonant structure of Bs→J/ψππ has been studied • 775 MeV < m(ππ) < 1550 MeV found to be CP-odd • And this range is subsequently used to measure: • φ_s = -0.019 ^+0.173 _-0.174 ^+0.004 _-0.003 rad • Using 0.37 fb^-1, measure Br and polarization of B_s→ J/ψ K̄*(Kπ) : Br( Bs→ J/ψ K̄*(892) ) = ( 4.4 ^+0.5 _-0.4 ± ^0.8 ) 10^-5 fL = 0.50 ± 0.08 ± 0.02 f// = 0.19 ^+0.10 _-0.08 ± 0.02 |AS|² = _0.07 ^+0.15 _-0.07 within 40 MeV/c² of K*⁰(892) • On schedule to collect about 2.2 fb^-1 at 8 TeV in 2012→.