Prospects for $P$ and $CP$ violation in ${\Lambda }_c^{+}$ decays with polarized beam at Super Tau-Charm Facility

Abstract

Weak decays of the charmed baryons offer an ideal platform to study parity ($P$) and charge conjugation-parity ($CP$) violation in quark sector, to stringently test the Standard Model and search for new physics. It is a key goal in the next-generation positron-electron collider, such as the Super Tau-Charm Facility (STCF). Thanks to the quantum-entangled pair production with super high luminosity and the possibility of beam polarization, STCF provides a unique environment to probe such symmetry violations with unprecedented sensitivity. In this paper, we evaluate the precisions of the $P$-violating parameters and subsequently obtain the expected sensitivity of the $CP$-violating parameters in charmed baryon decays of ${\Lambda }_c^{+}\to p{\pi }^0$, $p\eta$, $\Lambda K^{+}$, ${\Sigma }^0{K}^{+}$, and ${\Sigma }^{+}{K}_S^0$, regarding to different polarization setups in STCF. The study suggests that the implementation of longitudinal beam polarization in STCF would greatly enhance the experimental capability in studying $P$ and $CP$ violation.