Studies of Bs2∗^(5840)0 and B <inf>s 1</inf>(5830) ⁰ mesons including the observation of the Bs2∗^(5840)0→^B0KS0 decay in proton-proton collisions at √s=8TeV

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 B0 s meson decays into B(∗)+K− and B(∗)0K0 S, 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 B0 s 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 B0K0 S is observed, together with a measurement of its branching fraction relative to the B∗ s2(5840)0 → B+K− decay