# XX International Workshop on Deep-Inelastic Scattering and Related Subjects

26-30 March 2012
University of Bonn
Europe/Berlin timezone

## Recent Results of Double Helicity Asymmetries at PHENIX

27 Mar 2012, 09:35
25m
Lecture Hall, Institute for Physical Chemistry (University of Bonn)

Spin physics

### Speaker

Mr Scott Wolin (University of Illinois at Urbana-Champaign)

### Description

The determination of the gluon polarization within the proton, $\Delta G$, is one of the critical pieces to understanding the proton spin puzzle. Using collisions of polarized protons with $\sqrt{s}=200 \:GeV$ and $\sqrt{s}=500 \:GeV$ at the Relativistic Heavy Ion Collider (RHIC), PHENIX can access gluons and $\Delta G$ at leading order. Constraints on $\Delta G$ come from measurements of double longitudinal asymmetries, $A_{LL}$, of various particle production cross sections. We will present the recent $A_{LL}$ results at central $(|{\eta}|<0.35)$ and forward $(3.1 < |{\eta}| < 3.9)$ rapidities along with comparisons to various models of the gluon polarization. A summary of the current issues limiting the precision of these measurements will follow. Finally, we will discuss the possibilities in the near to mid-term future of the PHENIX $\Delta G$ program, specifically, constraining $\Delta G$ at low-x.

### Primary author

Mr Scott Wolin (University of Illinois at Urbana-Champaign)

### Presentation materials

 Proceedings Slides