Kinked tracks from $\Sigma^+$ baryons as a probe of light quark polarizations

TL;DR

This paper explores how kinked track signatures from $ ext{Sigma}^+$ baryons can be used to measure light quark polarizations in high-energy physics experiments, extending previous methods that used other baryons.

Contribution

It introduces a novel approach using $ ext{Sigma}^+$ baryons' kinked tracks to probe $s$ and $u$ quark polarizations, expanding the toolkit for polarization measurements.

Findings

Feasibility of using $ ext{Sigma}^+$ decay signatures in $tar t$ events.

Analysis of the kinked track detection method for $ ext{Sigma}^+$ decays.

Potential sensitivity to light quark polarizations in collider experiments.

Abstract

Jets initiated by energetic quarks carry in an obvious way approximate information about the original quark energy and momentum. In a less obvious way, they also carry information about the quark polarization. Previous works have shown how the polarization information can be extracted by ATLAS and CMS using events in which the quark hadronizes to an energetic baryon - $\Lambda_b$ for $b$ quarks, $\Lambda_c$ for $c$ quarks and $\Lambda$ for $s$ quarks. In this paper we extend these proposals to $\Sigma^+$ baryons, which can provide sensitivity to polarizations of $s$ and $u$ quarks. We analyze the various aspects of how the kinked track signature of the $\Sigma^+ \to p \pi^0$ decay can be used for this purpose. We evaluate the feasibility of such measurements in $t\bar t$ samples.