Measurements of $K_S^0$-$K_L^0$ asymmetries in the decays $\Lambda_c^+ \to pK_{L,S}^0$, $pK_{L,S}^0\pi^+\pi^-$ and $pK_{L,S}^0\pi^0$

TL;DR

This study measures the absolute branching fractions and $K_S^0$-$K_L^0$ asymmetries in $ ext{Lambda}_c^+$ decays, providing the first such measurements and finding no significant asymmetries.

Contribution

First measurements of $ ext{Lambda}_c^+$ decay branching fractions involving $K_L^0$, and the first determination of $K_S^0$-$K_L^0$ asymmetries in these decays.

Findings

Measured branching fractions for $ ext{Lambda}_c^+$ decays involving $K_L^0$.

First $K_S^0$-$K_L^0$ asymmetry measurements in charmed baryon decays.

No significant $K_S^0$-$K_L^0$ asymmetries observed within uncertainties.

Abstract

Using $e^+e^-$ annihilation data sets corresponding to an integrated luminosity of 4.5 $\text{fb}^{-1}$, collected with the BESIII detector at center-of-mass energies between 4.600 and 4.699 GeV, we report the first measurements of the absolute branching fractions $\mathcal{B}(\Lambda_c^+\to pK_{L}^{0})=(1.67 \pm 0.06 \pm 0. 04)\%$, $\mathcal{B}(\Lambda_c^+\to pK_{L}^{0}\pi^+\pi^-)=(1.69 \pm 0.10 \pm 0.05)\%$, and $\mathcal{B}(\Lambda_c^+\to pK_{L}^{0}\pi^0)=(2.02 \pm 0.13 \pm 0.05)\%$, where the first uncertainties are statistical and the second systematic. Combining with the known branching fractions of $\Lambda_c^+ \to pK_{S}^{0}$, $\Lambda_c^+ \to pK_{S}^{0}\pi^+\pi^-$, and $\Lambda_c^+ \to pK_{S}^{0}\pi^0$, we present the first measurements of the $K_{S}^{0}$-$K_{L}^{0}$ asymmetries $R(\Lambda_c^+, K_{S,L}^0X) = \frac{\mathcal{B}(\Lambda_c^+ \to K_{S}^{0} X) - \mathcal{B}(\Lambda_c^+ \to K_{L}^{0} X)}{\mathcal{B}(\Lambda_c^+ \to K_{S}^{0} X) + \mathcal{B}(\Lambda_c^+ \to K_{L}^{0} X)}$ in charmed baryon decays: $R(\Lambda_c^+, pK_{S,L}^0) = -0.025 \pm 0.031$, $R(\Lambda_c^+, pK_{S,L}^0\pi^+\pi^-) = -0.027 \pm 0.048$, and $R(\Lambda_c^+, pK_{S,L}^0\pi^0) =-0.015 \pm 0.046$. No significant asymmetries within the uncertainties are observed.