Precision measurement of the Λ c + , Ξ c + , and Ξ c 0 baryon lifetimes

© 2019 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the publish...

Full description

Bibliographic Details
Format: Article
Language:English
Published: American Physical Society (APS) 2021
Online Access:https://hdl.handle.net/1721.1/133731
Description
Summary:© 2019 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP 3 . We report measurements of the lifetimes of the Λc+, Ξc+ and Ξc0 charm baryons using proton-proton collision data at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb-1, collected by the LHCb experiment. The charm baryons are reconstructed through the decays Λc+→pK-π+, Ξc+→pK-π+ and Ξc0→pK-K-π+, and originate from semimuonic decays of beauty baryons. The lifetimes are measured relative to that of the D+ meson, and are determined to be τΛc+=203.5±1.0±1.3±1.4 fs, τΞc+=456.8±3.5±2.9±3.1 fs, τΞc0=154.5±1.7±1.6±1.0 fs, where the uncertainties are statistical, systematic, and due to the uncertainty in the D+ lifetime. The measurements are approximately 3-4 times more precise than the current world average values. The Λc+ and Ξc+ lifetimes are in agreement with previous measurements; however, the Ξc0 baryon lifetime is approximately 3.3 standard deviations larger than the world average value.