Measurement of the B${}_{\mathrm{s}}^0$ $\to$ J/$\psi$K${}_{\mathrm{S}}^0$ effective lifetime from proton-proton collisions at $\sqrt{s}$ = 13 TeV

Abstract

The effective lifetime of the B${}_{\mathrm{s}}^0$ meson in the decay B${}_{\mathrm{s}}^0$ $\to$ J/$\psi$K${}_{\mathrm{S}}^0$ is measured using data collected during 2016-2018 with the CMS detector in $\sqrt{s}$ = 13 TeV proton-proton collisions at the LHC, corresponding to an integrated luminosity of 140 fb${}^{-1}$. The effective lifetime is determined by performing a two-dimensional unbinned maximum likelihood fit to the B${}_{\mathrm{s}}^0$ meson invariant mass and proper decay time distributions. The resulting value of 1.59 $\pm$ 0.07 (stat) $\pm$ 0.03 (syst) ps is the most precise measurement to date and is in good agreement with the expected value.

Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/BPH-22-001 (CMS Public Pages)