Measurement of B_s⁰ mixing parameters from the flavor-tagged decay B_s⁰→J/ψφ

Abstract

From an analysis of the flavor-tagged decay B_s⁰→J/ψφ we obtain the width difference between the B_s⁰ light and heavy mass eigenstates, ΔΓ_s=0.19±0.07(stat)_-0.01^+0.02(syst) ps^-1, and the CP-violating phase, φ_s=-0.57_-0.30^+0.24(stat)_-0.02^+0.08(syst). The allowed 90% CL intervals of ΔΓ_s and φ_s are 0.06<ΔΓ_s<0.30 ps^-1 and -1.20<φ_s<0.06, respectively. The data sample corresponds to an integrated luminosity of 2.8 fb^-1 accumulated with the D0 detector at the Fermilab Tevatron collider.