Measurement of the Lifetime Difference between B_s Mass Eigenstates

摘要

We present measurements of the lifetimes and polarization amplitudes for B_s~0 → J/ψΦ and B_d~0 → J/ΨK~(*0) decays. Lifetimes of the heavy and light mass eigenstates in the B_s~0 system are separately measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time. Using 203 +- 15 B_s~0 decays we obtain T_L = (l.05_(-0.13)~(+0.16)+-0.02) Ps and T_H = (2.07_(-0.46)~(+0.58)+-0.03) ps. Expressed in terms of the difference Δs, and average Γ_s, of the decay rates of the two eigenstates, the results are ΔΓ_s/Γ_s, = (65_(-33)~(+25)+-1)% and ΔΓ_s, = (0.47_(-0.24)~(+0.19)+- 0.01) ps~(-1).