# Measurement of the $\Lambda_b$ lifetime in the exclusive decay $\Lambda_b \to J/\psi \Lambda$

Abstract : We have measured the Lambda_b lifetime using the exclusive decay Lambda_b to J/psi Lambda, based on 1.2 fb-1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda_b 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 Lambda_b lifetime to be tau(Lambda_b) = 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-)K0_S(pi+ pi-) to be tau(B0) = 1.501(+0.078,-0.074)(stat) +/ -0.050(syst)ps, yielding a lifetime ratio of tau(Lambda_b)/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 Lambda_b with respect to B mesons, in contrast to another recent measurement of significant precision.
Document type :
Journal articles

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Submitted on : Wednesday, May 9, 2007 - 2:42:37 PM
Last modification on : Saturday, May 22, 2021 - 3:33:55 AM

### Citation

V.M. Abazov, B. Abbott, M. Abolins, B.S. Acharya, M. Adams, et al.. Measurement of the $\Lambda_b$ lifetime in the exclusive decay $\Lambda_b \to J/\psi \Lambda$. Physical Review Letters, American Physical Society, 2007, 99, pp.142001. ⟨10.1103/PhysRevLett.99.142001⟩. ⟨in2p3-00145275⟩

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