Measurement of Double Helicity Asymmetry in Multi-Particle Production with Polarized Proton-Proton Collision at PHENIX

TL;DR

This paper reports the measurement of double helicity asymmetry in multi-particle production at RHIC, providing insights into the polarized gluon distribution in protons and ruling out the maximal positive polarization scenario.

Contribution

First measurement of double helicity asymmetry in multi-particle production at midrapidity with polarized proton collisions at RHIC.

Findings

Excludes the GRSV-max gluon polarization scenario

Provides constraints on the polarized gluon distribution in the proton

Enhances understanding of proton spin structure

Abstract

A goal of the PHENIX experiment is to obtain the polarized gluon distribution function in the proton. Double helicity asymmetry in multi-particle production with polarized proton-proton collision is measured at midrapidity with RHIC Run 2005 data. This result excludes the maximum positive gluon polarization ("GRSV-max").