Eur. Phys. J. C (2022) 82: 1071
https://doi.org/10.1140/epjc/s10052-022-11013-5

Regular Article - Theoretical Physics

Pursuit of new physics within the ${\mathrm{\Lambda }}_c\to \mathrm{\Delta }K$ decays

Department of Physics, Hunan Normal University, and Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, 410081, Changsha, China

^a wangdi@hunnu.edu.cn

Received: 17 September 2022
Accepted: 7 November 2022
Published online: 28 November 2022

Abstract

We point out the CP asymmetry in the chain decay of ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Delta }}^{+}K(t)(\to {\pi }^{+}{\pi }^{-})$ is determined by the branching fractions of ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Delta }}^{++}{K}^{-}$, ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Delta }}^{+}{K}_{S,L}^0$ and ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Delta }}^0{K}^{+}$ modes under the isospin symmetry. The ambiguities from loop-induced quantities and $SU{(3)}_F$ breaking hadronic effects are avoided. Once the CP asymmetry in the ${\mathrm{\Lambda }}_c^{+}$ decays into ${\mathrm{\Delta }}^{+}$ and neutral kaons is confirmed by experiments, we can check if it is beyond the Standard Model, or verify the CP-violating effect resulted from the interference between the Cabibbo-favored and the doubly Cabibbo-suppressed amplitudes with the neutral kaon mixing. Future measurements of branching fractions play a critical role in reducing the uncertainties.