Collective effects in light–heavy ion collisions

Abstract

We present results for the azimuthal anisotropy of charged hadron distributions in A+A, p+A, d+A, and 3 He+A collisions within the IP-Glasma+music model. Obtained anisotropies are due to the fluid dynamic response of the system to the fluctuating initial geometry of the interaction region. While the elliptic and triangular anisotropies in peripheral Pb+Pb collisions at √ s = 2.76 TeV are well described by the model, the same quantities in √ s = 5.02 TeV p+Pb collisions underestimate the experimental data. This disagreement can be due to neglected initial state correlations or the lack of a detailed description of the fluctuating spatial structure of the proton, or both. We further present predictions for azimuthal anisotropies in p+Au, d+Au, and 3 He+Au collisions at √ s = 200 GeV. For d+Au and 3 He+Au collisions we expect the detailed substructure of the nucleon to become less important.

Mapping the phases of quantum chromodynamics with beam energy scan

“…Recently it has been observed that flow-like multi-particle correlations also exist in small systems, such as the ones created in high energy p+p, d+Au and p+Pb collisions. While it is still being debated if the origin of these correlations is hydrodynamic evolution as it is in nucleus-nucleus collisions [280][281][282], it is interesting to see if these flow-like correlations disappear at lower collision energies. Such a measurement has been recently carried out by the PHENIX collaboration [283] and in Fig.…”

Heavy Ions Overview

“…A sizeable v 3 is found, which can be connected to the initial triangular asymmetries. The curves in the figure show several model calculations that include a fluid-expansion stage in to model the collision and produce the anisotropy in the final state [11,16,17,18,19]. The model curves are in good qualitative agreement with the measurements.…”

Small Collision Systems at RHIC

“…The agreement is better with the SONIC model, but the uncertainties on the data do not allow yet to invalidate the existence of the pre-equilibrium flow in these systems. The model with IPGlasma initial state and then hydrodynamical evolution [6] largely underestimates the data in p+Au collisions, while overestimates the measured flow in the d+Au and 3 He+Au collisions. Figure 2 shows the measured preliminary STAR data of v even 1 , v 3 and v 2 measurements in various collision systems from very large (U + U and Au + Au ) to moderately large (Cu + Au and Cu + Cu ) to small systems (d+Au and p+Au ).…”