A measurement of the Λb0 lifetime and mass in the decay channel Λb0→J/ψ(μ+μ-)Λ0(pπ -) is presented. The analysis uses a signal sample of about 2200 Λb0 and Λ̄b0 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 Λb0 lifetime and mass. They are measured to be τΛb=1.449±0.036(stat) ±0.017(syst) ps and mΛb=5619.7±0. 7(stat)±1.1(syst) MeV.
Aad, G., Abajyan, T., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdelalim, A. A., … Zwalinski, L. (2013). Measurement of the Λb0 lifetime and mass in the ATLAS experiment. Physical Review D - Particles, Fields, Gravitation and Cosmology, 87(3). https://doi.org/10.1103/PhysRevD.87.032002