Constraining Quark Transversity through Collins Asymmetry Measurements at STAR

TL;DR

This paper reports the first measurement of the Collins asymmetry in charged pion production within jets from transversely polarized proton collisions, providing insights into the quark transversity distributions.

Contribution

It presents novel experimental results of Collins asymmetry measurements at STAR, utilizing full jet reconstruction and pion identification at RHIC.

Findings

First Collins moment measurement in jets at STAR

Provides data constraining quark transversity distributions

Demonstrates feasibility of azimuthal asymmetry measurements in jets

Abstract

The quark transversity distributions are accessible via measurements of the azimuthal distribution of charged pions inside jets produced in collisions of transversely polarized protons. The STAR Detector at the Relativistic Heavy Ion Collider is capable of full jet reconstruction and charged pion identification in the mid-rapidity region. This proceeding presents the first results of the Collins moment of leading charged pions in jets reconstructed from 2.2 pb-1 of root(s) = 200 GeV transversely polarized (58%) proton data.