Measurements of exclusive B-s(0) decays at the Upsilon(5S) resonance

Abstract

Several exclusive B-s(0) decays are studied using a 1.86 fb(-1) data sample collected at the Upsilon(5S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. In the B-s(0)-> D-s(-)pi(+) decay mode we find 10 B-s(0) candidates and measure the corresponding branching fraction. Combining the B-s(0)-> D-s((*)-)pi(+), B-s(0)-> D-s((*)-)rho(+), B-s(0)-> J/psi phi, and B-s(0)-> J/psi eta decay modes, a significant B-s(0) signal is observed. The ratio sigma(e(+)e(-)-> B-s(*)(B) over bar (*)(s))/sigma(e(+)e(-)-> B-s((*))(B) over bar ((*))(s))=(93(-9)(+7)+/- 1)% is obtained at the Upsilon(5S) energy, indicating that B-s(0) meson production proceeds predominantly through the creation of B-s(*)(B) over bar (*)(s) pairs. The B-s(0) and B-s(*) meson masses are measured to be M(B-s(0))=(5370 +/- 1 +/- 3) MeV/c(2) and M(B-s(*))=(5418 +/- 1 +/- 3) MeV/c(2). Upper limits on the B-s(0)->gamma gamma, B-s(0)->phi gamma, B-s(0)-> K+K-, and B-s(0)-> Ds(*)+Ds(*)- branching fractions are also reported.