Multiplicity, average transverse momentum and azimuthal anisotropy in U+U collisions at $\sqrt{s_{NN}}$ = 200 GeV using AMPT model

TL;DR

This study uses the AMPT model to analyze how different uranium collision configurations affect particle multiplicity, flow, and anisotropy, revealing significant variations compared to gold collisions and highlighting the impact of nuclear shape and collision geometry.

Contribution

It provides the first detailed comparison of U+U collision configurations on flow and anisotropy observables using the AMPT model at 200 GeV.

Findings

U+U collisions increase charged particle multiplicity by 15-40% over Au+Au.

Tip-to-tip collisions produce the highest Nch, ET, and <pT> values.

v2 correlates with eccentricity and can be significantly larger in U+U than in Au+Au.

Abstract

Using a multi-phase transport (AMPT) model that includes the implementation of deformed Uranium nuclei, we have studied the centrality dependence of the charged particle multiplicity, <pT>, eccentricity (e2), triangularity (e3), their fluctuations, elliptic flow (v2) and triangular flow (v3) for different configurations of U+U collisions at midrapidity for \sqrt(s_NN)=200 GeV. The results are compared to the corresponding observations from Au+Au collisions. We find that for the U+U collisions the dNch/d\eta at midrapidity is enhanced by about 15-40% depending on the collision and model configuration chosen, compared to Au+Au collisions. The tip-to-tip collisions leads to the largest values of Nch,transverse energy (ET) and <pT>. The <e2> and its fluctuation shows a rich centrality dependence, whereas not much variations are observed for <e3> and its fluctuations. The U+U side-on-side collision configuration provides maximum values of <e2> and minimum values of eccentricity fluctuations, whereas for peripheral collisions and mid-central collisions minimum values of <e2> and maximum value of eccentricity fluctuations are observed for body-to-body configuration and the tip-to-tip configuration has minimum value of <e2> and maximum value of eccentricity fluctuations for central collisions. The calculated v2 closely correlates with the eccentricity in the model. It is smallest for the body-to-body configuration in peripheral and mid-central collisions while it is minimum for tip-to-tip configuration in central collisions. For peripheral collisions the v2 in U+U can be about 40% larger than in Au+Au whereas for central collisions it can be a factor 2 higher depending on the collision configuration. It is also observed that the v3(pT) is higher for tip-to-tip and body-to-body configurations compared to other systems for the collision centrality studied.