Measurement of the effective B0s→J/ψK0S lifetime

Abstract

This paper reports the first measurement of the effective B0s→J/ψK0S lifetime and an updated mea-surement of its time-integrated branching fraction. Both measurements are performed with a data sample, corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions, recorded by the LHCb experimentin 2011 at a centre-of-mass energy of 7 TeV. The results are:τeff J/ψK0S=1.75±0.12(stat)±0.07(syst)ps and B(B0s→J/ψK0S)=(1.97±0.23)×10−5. For the latter measurement, the uncertainty includes bothstatistical and systematic sources.