Measurement of the Lambdab lifetime in the exclusive decay Lambdab to J/psi Lambda
Abstract
We have measured the Lambdab lifetime using the exclusive decay Lambdab to J/psi Lambda, based on 1.2 fb-1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambdab decays, where the J/psi and Lambda are identified via the decays J/psi to mu+ mu- and Lambda to p pi, we measured the Lambdab lifetime to be tau(Lambdab) = 1.218(+0.130,-0.115)(stat) +/- 0.042(syst)ps. We also measured the B0 lifetime in the decay B0 to J/psi(mu+ mu-)K0S(pi+ pi-) to be tau(B0) = 1.501(+0.078,-0.074)(stat) +/ -0.050(syst)ps, yielding a lifetime ratio of tau(Lambdab)/tau(B0) = 0.811(+0.096,-0.087)(stat) +/ -0.034(syst). These measurements are consistent with the current world averages and support the shorter lifetime of the Lambdab with respect to B mesons, in contrast to another recent measurement of significant precision.