Highlights from BNL-RHIC-2012

TL;DR

This paper reviews recent experimental highlights from RHIC and CERN-LHC, focusing on the discovery and properties of the quark-gluon plasma, including new collision systems, energy scans, and particle suppression measurements.

Contribution

It provides a comprehensive overview of RHIC's 2012 results, including new collision systems, energy dependence of suppression, and insights into quark energy loss in the quark-gluon plasma.

Findings

Confirmation of sQGP at RHIC in 2005.

High pT suppression increases above 30 GeV energy.

No low pT thermal photon enhancement in d+Au collisions.

Abstract

Recent highlights from Brookhaven National Laboratory and the Relativistic Heavy Ion Collider (RHIC) are reviewed and discussed in the context of the discovery of the strongly interacting Quark Gluon Plasma (sQGP) at RHIC in 2005 as confirmed by results from the CERN-LHC Pb+Pb program. Outstanding RHIC machine operation in 2012 with 3-dimensional stochastic cooling and a new EBIS ion source enabled measurements with Cu+Au, U+U, for which multiplicity distributions are shown, as well as with polarized p-p collisions. Differences of the physics and goals of p-p versus A+A are discussed leading to a review of RHIC results on pi0 suppression in Au+Au collisions and comparison to LHC Pb+Pb results in the same range 5<pT<20 GeV. Results of the RHIC Au+Au energy scan show that high pT suppression takes over from the "Cronin Effect" for c.m. energies > 30 GeV. Improved measurements of direct photon production and correlation with charged particles at RHIC are shown, including the absence of a low pT (thermal) photon enhancement in d+Au collisions. Attempts to understand the apparent equality of the energy loss of light and heavy quarks in the QGP by means of direct measurements of charm and beauty particles at both RHIC and LHC are discussed.