Measurement of the absolute branching fraction of the inclusive decay Λc+→KS0X : (BESIII Collaboration)

Abstract

We report the first measurement of the absolute branching fraction of the inclusive decay Λc+→KS0X. The analysis is performed using an e+e- collision data sample corresponding to an integrated luminosity of 567 pb - 1 taken at s = 4.6 GeV with the BESIII detector. Using eleven Cabibbo-favored Λ¯c- decay modes and the double-tag technique, this absolute branching fraction is measured to be B(Λc+→KS0X)=(9.9±0.6±0.4)%, where the first uncertainty is statistical and the second systematic. The relative deviation between the branching fractions for the inclusive decay and the observed exclusive decays is (18.7 ± 8.3) % , which indicates that there may be some unobserved decay modes with a neutron or excited baryons in the final state.