Long range rapidity correlations as seen in the STAR experiment

We analyze long range rapidity correlations observed in the STAR experiment at RHIC. Our goal is to extract properties of the two particle correlation matrix, accounting for the analysis method of the STAR experiment. We find a surprisingly large correlation strength for central collisions of gold nuclei at highest RHIC energies. We argue that such correlations cannot be the result of impact parameter fluctuations.

Are the Angular Correlations in pA Collisions due to a Glasmion or Bose Condensation ?

Experiments at the LHC have recently reported results on the angular asymmetry coefficients $v_n[m]$, for various angular moments $n$ and orders of cumulants $m$, in high multiplicity p+Pb collisions. These coefficients are large, and have both even and odd moments. We discuss here some of the implications of these results for our understanding of the initial state of the collision (Color Glass Condensate) and for the evolution in the final state (Glasma and thermalized Quark Gluon Plasma). We show the Color Glass Condensate predicts large even moments, $v_n$ with $n$ an even integer. Odd moments are generated by final state interactions or fragmentation. For a multi-particle determination …

Studies of the hydrodynamic evolution of matter produced in fluctuations inp¯pcollisions and in ultrarelativistic nuclear collisions. II. Transverse-momentum distributions

Studies of the hydrodynamic evolution of matter produced in fluctuations inp¯pcollisions and in ultrarelativistic nuclear collisions

In this first paper of a series of two, we present a comprehensive study of the hydrodynamic evolution of matter produced in the central region of ultrarelativistic heavy-ion collisions and in high-multiplicity fluctuations of p-barp-italic collisions. We shall begin with a discussion of the limits of the applicability of a perfect-fluid hydrodynamic description of high-energy collisions. A simple bag-model equation of state is argued to have qualitative and semiquantitative features expected from lattice gauge theory and present theoretical understanding. We also discuss the boundary conditions for the perfect-fluid hydrodynamic equations, and what classes of simple events would correspond…

Cascade simulation of ultrarelativistic collisions

The dynamics of hot matter produced in ultrarelativistic heavy-ion collisions is studied with a cascade simulation. We model the putative quark-gluon plasma with independent globs of high-density matter. The hadronic phase is treated by explicit tracking of pion coordinates. We find that the pions make 0--2 collisions with globs and 1--3 collisions with other pions, under conditions expected for heavy ions at collider energies. The entropy increases by about 20% during the phase transition. The transverse momentum in the final state is almost entirely due to the momentum with which pions are emitted from the globs, except at extremely high densities where the hydrodynamic expansion of the p…