# Precision Measurement of the Mass and Lifetime of the ${\mathbf{\Xi }}_{b}^{-}$ Baryon

Abstract : We report on measurements of the mass and lifetime of the Xi_b^- baryon using about 1800 Xi_b^- decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb^{-1} collected by the LHCb experiment. The decays are reconstructed in the Xi_b^- --> Xi_c^0 pi^-, Xi_c^0 --> pK-K-pi+ channel and the mass and lifetime are measured using the Lambda_b^0 --> Lambda_c^+ pi- mode as a reference. We measure M(Xi_b^-) - M(Lambda_b^0) = 178.36 +- 0.46 +- 0.16 MeV/c^2 and tau(Xi_b^-)/tau(Lambda_b^0) = 1.089 +- 0.026 +- 0.011, where the uncertainties are statistical and systematic, respectively. These results lead to a factor of two better precision on the Xi_b^- mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-01070314
Contributor : Danielle Cristofol <>
Submitted on : Wednesday, October 1, 2014 - 9:42:14 AM
Last modification on : Thursday, February 25, 2021 - 10:58:33 AM

### Citation

R. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Ziad Ajaltouni, et al.. Precision Measurement of the Mass and Lifetime of the ${\mathbf{\Xi }}_{b}^{-}$ Baryon. Biophysical Reviews and Letters, World Scientific Publishing, 2014, 113 (24), pp.242002. ⟨10.1103/PhysRevLett.113.242002⟩. ⟨in2p3-01070314⟩

Record views