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

We investigate the exclusive semilpetonic decays of ${\mathrm{\Lambda }}_c^{+}\to (\mathrm{\Lambda }\mathrm{/}n){\mathrm{\ell }}^{+}{\nu }_{\mathrm{\ell }}(\mathrm{\ell }=e,\mu )$ 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 ${\mathrm{\Lambda }}_c^{+}\to (\mathrm{\Lambda }{e}^{+}{\nu }_e,\mathrm{\Lambda }{\mu }^{+}{\nu }_e,n{e}^{+}{\nu }_e,n{\mu }^{+}{\nu }_e)$ are about $(3.39,3.21,0.36,0.35)\mathrm{\%}$ 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 (${\beta }_{{\mathrm{\Lambda }}_c},{\beta }_{\mathrm{\Lambda }},{\beta }_n)=(0.58\pm 0.08,0.52\pm 0.08,0.44\pm 0.04)$.