Measurement of the Lambda-B Lifetime in the Decay Lambda-B -> J/psi Lambda With the D0 Detector

GUSTAVO OTERO Y GARZON

PHYSICAL REVIEW LETTERS

Año: 2005 p. 1020011 - 1020017

0031-9007

We present measurements of the Lb0 lifetime in the exclusive decay channel Lb0 à J/y L0, with J/y à m+m- and L0 à pp-, the B0 lifetime in the decay B0 à J/y Ks0 with J/y à m+m- and KS0 à p+ p- and the ratio of these lifetimes. The analysis is based on approximately 250 pb-1 of data recorded with the D0 detector in ppbar collisions at sqrt(s) = 1.96 TeV. The Lb0 lifetime is determined to be t(Lb0) = 1.22 +0.22-0.18 (stat) ± 0.04 (syst) ps, the B0 lifetime t( B0) = 1.40 +0.11-0.10 (stat) ± 0.03 (syst) ps, and the ratio t( Lb0)/ t(B0) = 0.87 +0:17-0:14 (stat) ± 0.03 (syst). In contrast with previous measurements using Semileptonic decays, this is the first determination of the Lb0 lifetime based on a fully reconstructed decay channel.