Observation of Bs0 mesons and measurement of the Bs0/B+ yield ratio in PbPb collisions at √SNN=5.02 TeV

The B-s(0) and B+ production yields are measured in PbPb collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data sample, collected with the CMS detector at the LHC, corresponds to an integrated luminosity of 1.7 nb(-1). The mesons are reconstructed in the exclusive decay channels B-s(0) -> J/psi (mu(+)mu(-))phi(K+K-) and B+ -> J/psi(mu(+)mu(-))K+ in the transverse momentum range 7-50 GeV/c and absolute rapidity 0-2.4. The B-s(0) meson is observed with a statistical significance in excess of five standard deviations for the first time in nucleus-nucleus collisions. The measurements are performed as functions of the transverse momentum of the B mesons and of the PbPb collision centrality. The ratio of production yields of B-s(0) and B+ is measured and compared to theoretical models that include quark recombination effects. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

The production yields of B-s(0) and B+ mesons in PbPb collisions are measured, and the first observation of B-s(0) meson in nucleus-nucleus collisions with statistical significance is reported. The measurements are performed as a function of the transverse momentum and the collision centrality, and compared to theoretical models.