$ \Lambda_c $ semileptonic decays

Abstract

Motivated by the recent experimental progress in the $ \Lambda_c $ decay that contains a neutron in the final state, we analyze the semileptonic decay $ \Lambda_c \rightarrow n \ell \nu_\ell $ in the framework of QCD sum rules. The transition form factors are analytically computed using three-point correlation functions and the Cutkosky cutting rules, which can be extrapolated into the physical region by employing the $ z $-series parametrization. The branching fractions of $ \Lambda_c \rightarrow n e^+ \nu_e $ and $ \Lambda_c \rightarrow n \mu^+ \nu_{\mu} $ are estimated to be $ (0.281\pm 0.056)\%$ and $ (0.275\pm 0.055)\% $, respectively. Furthermore, we calculate as well the relevant decay asymmetry observables sensitive to new physics beyond the standard model. The numerical results of semileptonic decays $ \Lambda_c \rightarrow \Lambda \ell \nu_\ell $ are also given and confronted to the latest experimental data.