Observation of B-s(0) -> J/psi f(0)(980) and Evidence for B-s(0) -> J/psi f(0)(1370)

Abstract

We report the observation of B-s(0) -> J/psi f(0(980)) and evidence for B-s(0) -> J/psi f(0)(1370), which are CP eignstate decay modes. These results are obtained from 121.4 fb(-1) of data collected at the Y(5S) resonance with the Belle detector at the KEKB e(+)e(-) collider. We measure the branching fractions B(B-s(0) -> J/psi f(0)(980); f(0)(980) -> pi(+)pi(-)) = (1.16(-0.19)(+0.31)(stat)(-0.17)(+0.15)(syst)(-0.18)(+0.26)(N-Bs(*)(B) over bars(*))) X 10(-4) with a significance of 8.4 sigma, and B(B-s(0) -> j/psi f(0)(1370); f(0)(1370) -> pi(+)pi(-)) = (0.34(-0.14)(+0.11)(stat)(-0.02)(+0.03)(syst)(-0.05)(+0.08) (N-Bs(*)(B) over bars(*))) X 10(-4) with a significance of 4.2 sigma. The last error listed is due to uncertainty in the number of produced B-s((*)) (B) over bar ((*))(s) pairs.