# Highlights from BNL and RHIC 2016

## TL;DR

This paper summarizes recent experimental results from BNL and RHIC, including spin asymmetries, flow measurements, and hard-scattering phenomena, highlighting advances in understanding quark-gluon interactions and nuclear matter under extreme conditions.

## Contribution

It reports new measurements and methods in heavy ion collisions, including flow, quark scaling, and di-hadron correlations, advancing the understanding of QCD phenomena at RHIC.

## Key findings

- Observation of transverse single spin asymmetries in polarized p+p collisions.
- Measurement of flow in U+U collisions.
- Di-hadron acoplanarity results that challenge TMD predictions.

## Abstract

Highlights of news from Brookhaven National Laboratory (BNL) and results from the Relativistic Heavy Ion Collider (RHIC) in the period July 2015-2016 are presented. Transverse single spin asymmetries from polarized p+p collisions are presented for $\pi^0$ and jets as a function of Feynman $x_F$. An energy scan to study the $\sqrt{s}$ dependence of collectivity and flow for small systems was performed as well as a high luminosity Au$+$Au run. The failure of a quench protection diode resulted in a pause in the run to replace it, but otherwise performance of RHIC was the best ever. Experimental results discussed are an elegant measurement from STAR of the force between anti-protons using HBT correlations, flow in U+U collisions, an improved method of generating constituent quarks by PHENIX and new Number of Quark Participants (NQP) scaling of $E_T$ distributions in p$+$p,d$+$Au and Au$+$Au which worked well. New hard-scattering results as a function of $\sqrt{s}$ in Au$+$Au central collisions are presented. Also, measurements of the di-hadron acoplanarity for $\pi^0 +h$ and $\gamma+h$ in p+p collisions at $\sqrt{s}=500$ GeV are presented in terms of the out-of-plane transverse momentum $p_{\rm out}$ which differ from the prediction of the TMD framework of parton transverse momentum dynamics.