Semileptonic decays of $\Lambda^{+}_{c}$ in light-front quark model with nonvalence contributions

We investigate the exclusive semilpetonic decays of $\Lambda^{+}_{c}\to (\Lambda/n) \ell^{+} \nu_{\ell}~(\ell=e,\mu)$ within the standard model by using the light-front quark model (LFQM). The form factor behaviors are obtained from the effective treatment of nonvalence contributions in addition to the valence ones in the Drell-Yan-West frame due to the Bethe-Salpeter formalism. Based on these form factors, we find that the decay branching ratios of $\Lambda^{+}_{c}\to (\Lambda e^{+} \nu_{e},\,\Lambda \mu^{+} \nu_{e} ,\, n e^{+} \nu_{e},\, n \mu^{+} \nu_{e})$ are about $(3.39,\,3.21,\,0.36,\,0.35)\%$ with the non-valence contributions, which are consistent with the recent experimental measurements at BESIII. Furthermore, we use the experimental data to fit the $\beta$ parameters in the baryonic distribution amplitudes under the LFQM, resulting in ($\beta_{\Lambda_{c}},\beta_{\Lambda}, \beta_{n})= (0.58\pm0.08, 0.52\pm0.08,0.44\pm0.04)$.