Higher harmonics of anisotropic flow at RHIC Beam Energy Scan energies

¹ Department of Physics, Institute of Science, Banaras Hindu University (BHU) - Varanasi, 221005, India
² Discipline of Natural Sciences, PDPM Indian Institute of Information Technology Design & Manufacturing Jabalpur, 482005, India

Received: 11 March 2025
Accepted: 3 June 2025

Abstract

In this work, we report the HYDJET++ simulation results for the higher flow harmonics like elliptic flow (v₂), triangular flow (v₃), quadrangular flow (v₄), and pentangular flow (v₅) in Au-Au collisions at 200 GeV, 62.4 GeV, 39 GeV, 27 GeV, 19.6 GeV, and 14.5 GeV. The higher harmonics were calculated based on the eccentricities ϵ_n and modulation in the rapidity profile ρ_n of the fireball. These parameters were treated as related to the impact parameter. Both approaches describe the data with some qualitative differences. The ρ₃ modulations show a linear correlation with v₃ while the ϵ₃ show a non-linear trend. A background v₄ was observed due to v₂ in its reaction plane while no such background was observed in the symmetry plane of v₃, and no background effects were observed for v₅. The constant a₅, which defines the strength of the pentangular modulation at a given impact parameter, was found to be independent of beam energy, hence, we predicted the v₅ of charged hadrons for the remaining energies using . Finally, we have discussed the effect of these harmonics in the final state distribution of charged hadrons.