# Radiative $b$-baryon decays to measure the photon and $b$-baryon polarization

## TL;DR

This paper proposes a method to measure photon and $b$-baryon polarization in radiative $b$-baryon decays, which can test the Standard Model and probe new physics with future LHC data.

## Contribution

It provides a comprehensive angular analysis framework for $b$-baryon radiative decays to extract polarization observables, enhancing the potential for new physics searches.

## Key findings

- Photon polarization asymmetry can be accurately measured.
- Simultaneous measurement of initial $b$-baryon polarization is feasible.
- Higher $b$-baryon yields improve sensitivity to new physics.

## Abstract

The radiative decays of $b$-baryons facilitate the direct measurement of photon helicity in $b\to s\gamma$ transitions thus serving as an important test of physics beyond the Standard Model. In this paper we analyze the complete angular distribution of ground state $b$-baryon ($\Lambda_{b}^{0}$ and $\Xi_{b}^{-}$) radiative decays to multibody final states assuming an initially polarized $b$-baryon sample. Our sensitivity study suggests that the photon polarization asymmetry can be extracted to a good accuracy along with a simultaneous measurement of the initial $b$-baryon polarization. With higher yields of $b$-baryons, achievable in subsequent runs of the Large Hadron Collider (LHC), we find that the photon polarization measurement can play a pivotal role in constraining different new physics scenarios.