Measurement of the Λ_{b}^{0} lifetime and mass in the ATLAS experiment

A measurement of the Lamda0b lifetime and mass in the decay channe Λ_{b}^{0) to J/Psi(mu mu) Λ(p pai) is presented. The analysis uses a signal sample of about 2200 Λ_{b}^{0) and antiΛ_{b}^{0) 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 Lamda_b lifetime and mass. They are measured to be tau_Λ_{b}^{0) =1.4490 +- 036(stat)+- 0.017(syst) ps and m_Λ_{b}^{0) =5619.70+-0.7(stat) +- 1.1(syst) MeV.