Based on 586 $\rm{ pb^{ -1}}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy of $\sqrt{ s}=4.6~\rm{ GeV}$ with the BESIII detector at the BEPCII collider, the absolute branching fraction of $\Lambda_c^+ \to p K^0_{ \mathrm{ S}}\eta$ decays is measured for the first time to be $\mathcal{ B}(\Lambda_c^+ \to p K^0_{ \mathrm{ S}}\eta) = (0.414 \pm 0.084 \pm 0.028)\%$, 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 $\frac{ \mathcal{ B}(\Lambda_c^+ \to p K^0_{ \mathrm{ S}}\eta)}{ \mathcal{ B}(\Lambda_c^+ \to p K^-\pi^+)}$, and consistent with theoretical predictions of SU(3) flavor symmetry.
Categories: hep-ex