Measurements of absolute branching fractions for $Λ^+_c\toΞ^0K^+$ and $Ξ(1530)^0K^+$

Abstract

We report the first measurements of absolute branching fractions for the $W$-exchange-only processes $\Lambda^+_c\to\Xi^0K^+$ and $\Lambda^+_c\to\Xi(1530)^0K^+$ with the double-tag technique, by analyzing an $e^+e^−$ collision data sample, that corresponds to an integrated luminosity of 567 pb$^{−1}$ collected at a center-of-mass energy of 4.6 GeV by the BESIII detector. The branching fractions are measured to be $\mathcal{B}(\Lambda^+_c\to\Xi^0K^+)=(5.90\pm0.86\pm0.39)\times10^{-3}$ and $\mathcal{B}(\Lambda^+_c\to\Xi(1530)^0K^+)=(5.02\pm0.99\pm0.31)\times10^{-3}$, where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.