Improved analysis on the semi-leptonic decay ${\Lambda }_c\to \Lambda {\ell }^{+}\nu$ from QCD light-cone sum rules

Abstract

With the renewed distribution amplitudes of $\Lambda$, we present a reanalysis on the semi-leptonic decay ${\Lambda }_c\to \Lambda {\ell }^{+}\nu$ by use of the light-cone sum rule approach with two kinds of interpolating currents. The form factors describing the decay process are obtained and used to predict the decay width. With the inclusion of up to twist-6 contributions the calculations give the decay width $\Gamma =(10.04\pm 0.88)\times 10^{-14}GeV$ for Chernyak-Zhitnitsky-type(CZ-type) current and $\Gamma =(6.45\pm 1.06)\times 10^{-14}GeV$ for Ioffe-type current. The Ioffe-type interpolating current is found to be better for the estimation of the decay rate from a comparison with experimental data.

Comments: 12 pages, 4 figures