Highlights from BNL and RHIC 2016

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.Comment: Invited lecture at the International School of Subnuclear Physics (ISSP) 54th Course, "The New Physics Frontiers in the LHC-2 Era", Erice, Sicily, Italy, June 14--23, 2016, 16 pages, 19 figure

Highlights from BNL-RHIC-2012

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.Comment: Invited lecture at the International School of Subnuclear Physics, 50th Course, "What we would like LHC to give us", Erice, Sicily, Italy, June 23-July 2, 2012. 16 pages, 12 figure

Waiting for the W and the Higgs

The search for the left-handed $W^{\pm}$ bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.Comment: 23 pages 12 figures, accepted for publication in The European Physical Journal

How hadron collider experiments contributed to the development of QCD: from hard-scattering to the perfect liquid

A revolution in elementary particle physics occurred during the period from the ICHEP1968 to the ICHEP1982 with the advent of the parton model from discoveries in Deeply Inelastic electron-proton Scattering at SLAC, neutrino experiments, hard-scattering observed in p$+$p collisions at the CERN ISR, the development of QCD, the discovery of the J/$\Psi$ at BNL and SLAC and the clear observation of high transverse momentum jets at the CERN SPS $\bar{p}+p$ collider. These and other discoveries in this period led to the acceptance of QCD as the theory of the strong interactions. The desire to understand nuclear physics at high density such as in neutron stars led to the application of QCD to this problem and to the prediction of a Quark-Gluon Plasma (QGP) in nuclei at high energy density and temperatures. This eventually led to the construction of the Relativistic Heavy Ion Collider (RHIC) at BNL to observe superdense nuclear matter in the laboratory. This article discusses how experimental methods and results which confirmed QCD at the first hadron collider, the CERN ISR, played an important role in experiments at the first heavy ion collider, RHIC, leading to the discovery of the QGP as a perfect liquid as well as discoveries at RHIC and the LHC which continue to the present day.Comment: 63 pages, 45 figures, accepted for publication in The European Physical Journal