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

Abstract

Based on an e+e− collision data sample corresponding to an integrated luminosity of 567pb−1 taken at the center-of-mass energy of s=4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay Λc+→Λ+X to be B(Λc+→Λ+X)=(38.2−2.2+2.8±0.8)% 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 ACP≡B(Λc+→Λ+X)−B(Λ¯c−→Λ¯+X)B(Λc+→Λ+X)+B(Λ¯c−→Λ¯+X)=(2.1−6.6+7.0±1.4)%, a statistically limited result with no evidence of CP violation.