Book Description
We present a study of Bs0 decays to the CP-odd final state J/[psi] f0(980) with J/[psi] 2!æ+æ- and f0(980) 2![pi]+[pi]-. Using pp̄ collision data with an integrated luminosity of 3.8 fb-1 collected by the CDF II detector at the Tevatron we measure a Bs0 lifetime of [tau](B0s 2!J/[psi] f0(980)) = 1.70-0.11+0.12(stat) " 0.03(syst) ps. This is the first measurement of the Bs0} lifetime in a decay to a CP eigenstate and corresponds in the standard model to the lifetime of the heavy Bs0 eigenstate. We also measure the product of branching fractions of B0s 2!J/[psi] f0(980) and f0(980) 2![pi]+[pi]- relative to the product of branching fractions of B0s 2!J/[psi][phi] and [phi]2!+K- to be Rf0/[psi] = 0.257 " 0.020(stat) " 0.014(syst), which is the most precise determination of this quantity to date.