Measurement of the Absolute Branching Fraction of the Inclusive Decay $Λ_{c}^{+} \to Λ+ X$

Ablikim, M. ; Achasov, M. N. ; Ahmed, S. ; Albrecht, M. ; Alekseev, M. ; Amoroso, A. ; An, F. F. ; An, Q. ; Bai, J. Z. ; Bai, Y. ; Bakina, O. ; Ferroli, R. Baldini ; Ban, Y. ; Bennett, D. W. ; Bennett, J. V. ; Berger, N. ; Bertani, M. ; Bettoni, D. ; Bian, J. M. ; Bianchi, F. ; Boger, E. ; Boyko, I. ; Briere, R. A. ; Cai, H. ; Cai, X.

Based on an $e^+e^-$ collision data sample corresponding to an integrated luminosity of 567pb$^{−1}$ taken at the center-of-mass energy of $\sqrt{s}$=4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay $\Lambda_{c}^{+} \to \Lambda + X$ to be $\mathcal{B}(\Lambda_{c}^{+} \to \Lambda + X)=(38.2^{+2.8}_{-2.2}\pm0.8)\%$ using the double-tag method, where $X$ refers to any possible final state particles. In addition, we search for direct CP violation in the charge asymmetry of this inclusive decay for the first time, and obtain $\mathcal{A}_{CP} \equiv \frac{\mathcal{B}(\Lambda_{c}^{+} \to \Lambda + X)-\mathcal{B}(\bar{\Lambda}_{c}^{-} \to \bar{\Lambda} + X)}{\mathcal{B}(\Lambda_{c}^{+} \to \Lambda + X)+\mathcal{B}(\bar{\Lambda}_{c}^{-} \to \bar{\Lambda} + X)} = (2.1^{+7.0}_{-6.6}\pm1.4)\%$, a statistically limited result with no evidence of CP violation.

Publication Date:
Aug 07 2018
Date Submitted:
Jul 01 2019
Pagination:
62003
ISSN:
0031-9007
Citation:
Physical Review Letters
121
6
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