Semileptonic weak decays of antitriplet charmed baryons in the light-front formalism

Abstract

We systematically study the semileptonic decays of ${\mathbf{B}}_{\mathbf{c}}\ensuremath{\rightarrow}{\mathbf{B}}_{\mathbf{n}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ in the light-front constituent quark model, where ${\mathbf{B}}_{\mathbf{c}}$ represents the antitriplet charmed baryons of $({\mathrm{\ensuremath{\Xi}}}_{c}^{0},{\mathrm{\ensuremath{\Xi}}}_{c}^{+},{\mathrm{\ensuremath{\Lambda}}}_{c}^{+})$ and ${\mathbf{B}}_{\mathbf{n}}$ corresponds to the octet ones. We determine the spin-flavor structures of the constituents in the baryons with the Fermi statistics and calculate the decay branching ratios ($\mathcal{B}$s) and averaged asymmetry parameters ($\ensuremath{\alpha}$s) with the helicity formalism. In particular, we find that $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e},n{e}^{+}{\ensuremath{\nu}}_{e})=\phantom{\rule{0ex}{0ex}}(3.55\ifmmode\pm\else\textpm\fi{}1.04,0.36\ifmmode\pm\else\textpm\fi{}0.15)%$, $\mathcal{B}({\mathrm{\ensuremath{\Xi}}}_{c}^{+}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{0}{e}^{+}{\ensuremath{\nu}}_{e},{\mathrm{\ensuremath{\Sigma}}}^{0}{e}^{+}{\ensuremath{\nu}}_{e},\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e})=(11.3\ifmmode\pm\else\textpm\fi{}3.35)$, $0.33\ifmmode\pm\else\textpm\fi{}0.09$, $0.12\ifmmode\pm\else\textpm\fi{}0.04%$, and $\mathcal{B}({\mathrm{\ensuremath{\Xi}}}_{c}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e},{\mathrm{\ensuremath{\Sigma}}}^{\ensuremath{-}}{e}^{+}{\ensuremath{\nu}}_{e})=(3.49\ifmmode\pm\else\textpm\fi{}0.95,0.22\ifmmode\pm\else\textpm\fi{}0.06)%$. Our results agree with the current experimental data. Our prediction for $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}n{e}^{+}{\ensuremath{\nu}}_{e})$ is consistent with those in the literature, which can be measured by the charm facilities, such as BESIII and BELLE. Some of our results for the ${\mathrm{\ensuremath{\Xi}}}_{c}^{+(0)}$ semileptonic channels can be tested by the experiments at BELLE as well as the ongoing ones at LHCb and BELLEII.

Topics & Concepts