Studies of B*s2(5840)0 and Bs1(5830)0 mesons including the observation of the B*s2(5840)0 → B0K0S decay in proton-proton collisions at √s = 8 TeV

Abstract

Measurements of B*s2(5840)0 and Bs1(5830)0 mesons are performed using a data sample of protonproton collisions corresponding to an integrated luminosity of 19.6 fb−1, collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV. The analysis studies P-wave B0s meson decays into B(*)+K− and B(*)0K0S , where the B+ and B0 mesons are identified using the decays B+ → J/ψK+ and B0 → J/ψK+ (892)0. The masses of the P-wave B0s meson states are measured and the natural width of the B*s2(5840)0 state is determined. The first measurement of the mass difference between the charged and neutral B* mesons is also presented. The B*s2(5840)0 decay to B0K0S is observed, together with a measurement of its branching fraction relative to the B*s2(5840)0 → B+K− decay.