Precision measurement of the Λ<i><sub>c</sub></i><SUP>+</SUP>, Ξ<i><sub>c</sub></i><SUP>+</SUP>, and Ξ<sub>c</sub><SUP>0</SUP> baryon lifetimes



Aaij, R, Beteta, C Abellan, Adeva, B, Adinolfi, M, Aidala, CA, Ajaltouni, Z, Akar, S, Albicocco, P, Albrecht, J, Alessio, F
et al (show 839 more authors) (2019) Precision measurement of the Λ<i><sub>c</sub></i><SUP>+</SUP>, Ξ<i><sub>c</sub></i><SUP>+</SUP>, and Ξ<sub>c</sub><SUP>0</SUP> baryon lifetimes. PHYSICAL REVIEW D, 100 (3). 032001-.

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Abstract

We report measurements of the lifetimes of the $\Lambda_c^+$, $\Xi_c^+$ and $\Xi_c^0$ 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 $\Lambda_c^+\to pK^-\pi^+$, $\Xi_c^+\to pK^-\pi^+$ and $\Xi_c^0\to pK^-K^-\pi^+$, and originate from semimuonic decays of beauty baryons. The lifetimes are measured relative to that of the $D^+$ meson, and are determined to be \begin{align*} \tau_{\Lambda_c^+} &= 203.5\pm1.0\pm1.3\pm1.4~{\rm fs}, \newline \tau_{\Xi_c^+} &= 456.8\pm3.5\pm2.9\pm3.1~{\rm fs}, \newline \tau_{\Xi_c^0} &= 154.5\pm1.7\pm1.6\pm1.0~{\rm fs}, \end{align*} 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 $\Lambda_c^+$ and $\Xi_c^+$ lifetimes are in agreement with previous measurements; however, the $\Xi_c^0$ baryon lifetime is approximately 3.3 standard deviations larger than the world average value.

Item Type: Article
Additional Information: 9 pages, 2 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2019-008.html
Uncontrolled Keywords: hep-ex, hep-ex, hep-ph
Depositing User: Symplectic Admin
Date Deposited: 03 Sep 2019 15:29
Last Modified: 12 Oct 2023 11:06
DOI: 10.1103/PhysRevD.100.032001
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3053331