Semileptonic decays of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi mathvariant="normal">Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup></mml:math> in dynamical approaches

Abstract

We study the semileptonic decays of ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}(n){\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ in two relativistic dynamical approaches of the light-front constituent quark model (LFCQM) and MIT bag model (MBM). By considering the Fermi statistic between quarks and determining spin-flavor structures in baryons along with the helicity formalism in the two different dynamical models, we calculate the branching ratios ($\mathcal{B}\mathrm{s}$) and averaged asymmetry parameters ($\ensuremath{\alpha}\mathrm{s}$) in the decays. Explicitly, we find that $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e})=(3.36\ifmmode\pm\else\textpm\fi{}0.87,3.48)%$ and $\ensuremath{\alpha}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e})=(\ensuremath{-}0.97\ifmmode\pm\else\textpm\fi{}0.03,\ensuremath{-}0.83)$ in (LFCQM, MBM), in comparison with the data of $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e})=(3.6\ifmmode\pm\else\textpm\fi{}0.4)%$ and $\ensuremath{\alpha}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e})=\ensuremath{-}0.86\ifmmode\pm\else\textpm\fi{}0.04$ given by the Particle Data Group, respectively. We also predict that $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}n{e}^{+}{\ensuremath{\nu}}_{e})=(0.57\ifmmode\pm\else\textpm\fi{}0.15,3.6\ifmmode\pm\else\textpm\fi{}1.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ and $\ensuremath{\alpha}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}n{e}^{+}{\ensuremath{\nu}}_{e})=(\ensuremath{-}0.98\ifmmode\pm\else\textpm\fi{}0.02,\ensuremath{-}0.96\ifmmode\pm\else\textpm\fi{}0.04)$ in LFCQM with two different scenarios for the momentum distributions of quarks in the neutron and $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}n{e}^{+}{\ensuremath{\nu}}_{e})=0.279\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$ and $\ensuremath{\alpha}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}n{e}^{+}{\ensuremath{\nu}}_{e})=\ensuremath{-}0.87$ in MBM, which could be tested by the ongoing experiments at BESIII, LHCb, and BELLEII.

Topics & Concepts