# Measurements of $CP$ asymmetries in charmless four-body $\Lambda_b$ and $\Xi_b^0$ decays

## TL;DR

This study searches for $CP$ violation in charmless four-body decays of $ ext{Lambda}_b$ and $ ext{Xi}_b^0$ baryons using LHCb data, finding no significant effects across multiple decay channels and kinematic regions.

## Contribution

It presents the first comprehensive measurement of $CP$ asymmetries in these specific baryon decays, utilizing a novel method to cancel production and detection asymmetries.

## Key findings

- No significant $CP$ violation observed in any decay channel.
- Measured 18 $CP$ asymmetries across full phase space and specific kinematic regions.
- Results set constraints on $CP$ violation in charmless baryon decays.

## Abstract

A search for $CP$ violation in charmless four-body decays of $\Lambda_b$ and $\Xi_b^0$ baryons with a proton and three charged mesons in the final state is performed. To cancel out production and detection charge-asymmetry effects, the search is carried out by measuring the difference between the $CP$ asymmetries in a charmless decay and in a decay with an intermediate charmed baryon with the same particles in the final state. The data sample used was recorded in 2011 and 2012 with the LHCb detector and corresponds to an integrated luminosity of $3 {\rm fb}^{-1}$. A total of 18 $CP$ asymmetries are considered, either accounting for the full phase space of the decays or exploring specific regions of the decay kinematics. No significant $CP$-violation effect is observed in any of the measurements.