Formulae for the Analysis of the Flavor-Tagged Decay B^0_s --> Jpsi phi

Understand

Differential rates in the decay B^0_s --> Jpsi phi, with phi --> K^+K^- and Jpsi --> mu^+ mu^- are sensitive to the CP-violation phase beta_s, predicted to be very small in the standard model.

• The analysis of B^0_s --> Jpsi phi decays is also suitable for measuring the B^0_s lifetime, the decay width difference DeltaGamma_s between the B^0_s mass eigenstates, and the B^0_s oscillation frequency Delta m even if appreciable CP violation does not occur.
• In this paper we present normalized probability densities useful in maximum likelihood fits, extended to allow for S-wave contributions on one hand and for the effects of direct CP violation on the other.
• Our treatment of the S-wave contributions includes the strong variation of the S-wave/P-wave amplitude ratio with m(K^+K^-) across the phi resonance, which was not considered in previous work.