Abstract
A measurement of the _b0 lifetime and mass in the decay channel _b0_J/_(_+_-)_0(p_ -) is presented. The analysis uses a signal sample of about 2200 _b0 and __b0 decays that are reconstructed in 4.9 fb -1 of ATLAS pp collision data collected in 2011 at the LHC center-of-mass energy of 7 TeV. A simultaneous mass and decay time maximum likelihood fit is used to extract the _b0 lifetime and mass. They are measured to be __b=1.449±0.036(stat) ±0.017(syst) ps and m_b=5619.7±0. 7(stat)±1.1(syst) MeV. © 2013 CERN.