PHENIX results on centrality dependence of yields and correlations in $d$+Au collisions at $\sqrt{s_{_{NN}}}$=200\,GeV

TL;DR

This paper reports PHENIX measurements of particle yields and correlations in d+Au collisions at 200 GeV, revealing a ridge structure and persistent azimuthal anisotropy up to high transverse momentum, with dependence on collision centrality.

Contribution

It presents the first detailed analysis of high p_T particle correlations and azimuthal anisotropy in d+Au collisions at RHIC, extending the p_T range and identifying ridge-like structures.

Findings

Ridge-like azimuthal correlations observed at large rapidity gaps.

Azimuthal anisotropy persists up to 6 GeV/c in transverse momentum.

Correlation structures depend on collision centrality.

Abstract

PHENIX has measured the transverse momentum ($p_{\rm T}$) spectra and two particle angular correlations for high $p_{\rm T}$ particles in $d$+Au collisions at $\sqrt{s_{_{NN}}}$=200\,GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge like structure. Using the $\pi^0$ reconstructed in the EMCal, we have successfully extended the $p_{\rm T}$ reach of the correlation up to 8\,GeV/$c$. We find that the azimuthal anisotropy of hadrons found at low $p_{\rm T}$ persists up to 6\,GeV/$c$ with a significant centrality and $p_{\rm T}$ dependence, similar to what was observed in A+A collisions.