Measurement of the Absolute Branching Fraction of the Inclusive Semileptonic Lambda(+)(c) Decay

Abstract

Using a data sample of e(+)e(-) collisions corresponding to an integrated luminosity of 567 pb(-1) collected at a center-of-mass energy of root s = 4.6 GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive semileptonic Lambda(+)(c) decay with a double-tag method. We obtain B(Lambda(+)(c) -> Xe+nu(e)) = (3.95 +/- 0.34 +/- 0.09)%, where the first uncertainty is statistical and the second systematic. Using the known Lambda(+)(c) lifetime and the charge-averaged semileptonic decay width of nonstrange charmed mesons (D-0 and D+), we obtain the ratio of the inclusive semileptonic decay widths Gamma(Lambda(+)(c) -> Xe+nu(e))/(Gamma) over bar (D -> Xe+nu(e)) = 1.26 +/- 0.12.