Abstract : A measurement of the Lambda_b lifetime and mass in the decay channel Lambda_b -> J/psi(mu^+ mu^-) Lambda^0(p pi^-) is presented. The analysis uses a signal sample of about 2200 Lambda_b and anti-Lambda_b 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 Lambda_b lifetime and mass. They are measured to be tau(Lambda_b) = 1.449 ± 0.036(stat) ± 0.017(syst) ps andm(Lambda_b) = 5619.7 ± 0.7(stat) ± 1.1(syst) MeV.
G. Aad, S. Aoun, C. P. Bee, C. Bertella, N. Bousson, et al.. Measurement of the Lambda_b lifetime and mass in the ATLAS experiment. Physical Review D, American Physical Society, 2013, 87, pp.032002. <10.1103/PhysRevD.87.032002>. <in2p3-00716649>