Measurement of the Bs0 → J/ψKS0 effective lifetime from proton-proton collisions at √s=13 TeV

The effective lifetime of the Bs0 meson in the decay Bs0?J/?KS0 is measured using data collected during 2016–2018 with the CMS detector in 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 Bs0 meson invariant mass and proper decay time distributions. The resulting value of 1.59 ± 0.07(stat) ± 0.03(syst) ps is the most precise measurement to date and is in good agreement with the expected value. © The Author(s) 2024.