Highlights from BNL and RHIC 2015

TL;DR

This paper summarizes key news and scientific results from BNL and RHIC in 2014-2015, including the startup of a new synchrotron, outstanding collider performance, new p+A collision data, and insights into quark-gluon plasma and QCD critical point searches.

Contribution

It reports the first asymmetric p+Au and p+Al collision runs at RHIC and discusses new measurements related to the QCD critical point and quark-gluon plasma.

Findings

RHIC achieved record integrated luminosity in p+p collisions at 200 GeV.

First asymmetric p+Au and p+Al collision data were collected.

Net-charge fluctuation measurements support existing QCD critical point theories.

Abstract

Highlights of news from Brookhaven National Laboratory (BNL) and results from the Relativistic Heavy Ion Collider (RHIC) in the period July 2014-June 2015 are presented. The news this year was mostly very positive. The major event at BNL was the startup and dedication of the new NSLS II, "the World's brightest Synchrotron Light Source". The operation of RHIC was outstanding with a polarized p+p run at $\sqrt{s}=200$ GeV with integrated luminosity that exceeded the sum of all previous p+p integrated luminosity at this $\sqrt{s}$. For the first time at RHIC asymmetric p+Au and p+Al runs were made but the p+Al run caused damage in the PHENIX forward detectors from quenches that were inadequately shielded for this first p+A run. This was also the 10th anniversary of the 2005 announcement of the Perfect Liquid Quark Gluon Plasma at RHIC and a review is presented of the discoveries leading to this claim. A new result on net-charge fluctuations (with no particle identification) from PHENIX based on previous scans over beam energy to look for a QCD critical point is discussed which combined with Lattice QCD calculations and smaller errors on the higher cumulants than previous measurements led to calculations of the baryon chemical potential and freezeout temperature in agreement with the best accepted analysis from baryon/anti-baryon ratio measurements.