B′→BγandΩ−→ΛK−decays based on dimension-five effective operators

Abstract

We have examined the electromagnetic weak decays of strange baryons induced by the dimension-five effective weak Hamiltonian of the form ${m}_{s}{\overline{d}}_{L}{\ensuremath{\sigma}}_{\ensuremath{\mu}\ensuremath{\nu}}{G}^{\ensuremath{\mu}\ensuremath{\nu}}{s}_{R}+{m}_{s}{\overline{s}}_{R}{\ensuremath{\sigma}}_{\ensuremath{\mu}\ensuremath{\nu}}{G}^{\ensuremath{\mu}\ensuremath{\nu}}{d}_{L}$ and ${m}_{d}{\overline{d}}_{R}{\ensuremath{\sigma}}_{\ensuremath{\mu}\ensuremath{\nu}}{G}^{\ensuremath{\mu}\ensuremath{\nu}}{s}_{L}+{m}_{d}{\overline{s}}_{L}{\ensuremath{\sigma}}_{\ensuremath{\mu}\ensuremath{\nu}}{G}^{\ensuremath{\mu}\ensuremath{\nu}}{d}_{R}$ originally due to Minkowski and others. In particular for ${\ensuremath{\Sigma}}^{+}\ensuremath{\rightarrow}p\ensuremath{\gamma}$, we find that the asymmetry ${\ensuremath{\alpha}}_{\ensuremath{\Sigma}}\ensuremath{\simeq}\ensuremath{-}0.91$ and the branching ratio $B({\ensuremath{\Sigma}}^{+}\ensuremath{\rightarrow}p\ensuremath{\gamma})\ensuremath{\simeq}0.42\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. The process ${\ensuremath{\Omega}}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\Lambda}{K}^{\ensuremath{-}}$ has also been discussed.