Semileptonic Decays of $Λ\to p \ell^{-} \barν_{\ell}$ in the Light-Front Dynamics

Abstract

We investigate the exclusive semileptonic decays of $Λ\to p \ell^{-} \barν_{\ell}~(\ell=e,μ)$ within the Standard Model using the light-front quark model. The transition form factor behaviors of $Λ\to p$ 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 obtain that the branching ratios of $Λ\to p e^{-} \barν_{e}$ and $p μ^{-} \barν_μ$, including nonvalence contributions, are around $8.32\times 10^{-4}$ and $1.31\times 10^{-4}$, which are consistent with the latest measurements from the BESIII Collaboration, respectively. Our results indicate that nonvalence contributions can play a non-negligible role in the semileptonic baryon decays within the light-front framework.