Measurement of the absolute branching fraction of ${\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta$ decays

Abstract

Based on 586 $\mathrm{p}{\mathrm{b}}^{-\mathrm{1}}$ of $e^{+}{e}^{-}$ annihilation data collected at a center-of-mass energy of $\sqrt{s}=4.6\mathrm{GeV}$ with the BESIII detector at the BEPCII collider, the absolute branching fraction of ${\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta$ decays is measured for the first time to be $\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta )=(0.414\pm 0.084\pm 0.028)\text{\%}$, where the first uncertainty is statistical and the second is systematic. The result is compatible with a previous CLEO result on the relative branching fraction $\frac{\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0\eta )}{\mathcal{B}({\mathrm{\Lambda }}_c^{+}\to p{K}^{-}{\pi }^{+})}$, and consistent with theoretical predictions of SU(3) flavor symmetry.