Amplitude analysis of the $\Xi^+_c\to pK^-\pi^+$ decay and $\Xi^+_c$ baryon polarization measurement in semileptonic beauty-hadron decays

TL;DR

This paper performs an amplitude analysis of the $\\Xi^+_c\to pK^-\pi^+$ decay and measures the $\\Xi^+_c$ polarization in semileptonic beauty-hadron decays using LHCb data, revealing resonance structures and a significant polarization.

Contribution

It introduces a detailed amplitude model for the decay and demonstrates its effectiveness for polarization measurements, advancing understanding of $\\Xi^+_c$ decay dynamics.

Findings

Resonance fractions and decay parameters reported

Significant $\\Xi^+_c$ polarization observed

Decay model shows high sensitivity to polarization

Abstract

An amplitude analysis of the $\Xi^+_c\to pK^-\pi^+$ decay together with a measurement of the $\Xi^+_c$ polarization vector in semileptonic beauty-hadron decays is presented. The analysis is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 ${\rm fb}^{-1}$. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. A sizeable $\Xi^+_c$ polarization is found. A large sensitivity of the $\Xi^+_c\to pK^-\pi^+$ decay to the polarization is seen, making the amplitude model suitable for $\Xi^+_c$ polarization measurements in other systems.