Influence of jets and decays of resonances on the triangular flow in ultrarelativistic heavy-ion collisions

TL;DR

This study investigates how jets and resonance decays influence the triangular flow in ultrarelativistic Pb+Pb collisions at LHC energies, revealing their effects on flow magnitude, spectra, and scaling behaviors.

Contribution

It provides a detailed analysis of the impact of resonance decays and jets on triangular flow using the extsc{hydjet++} model, highlighting their similar effects on flow harmonics.

Findings

Resonance decays increase $v_3(p_T)$ at high transverse momentum.

Jets are the main source of scaling violation at LHC energies.

Resonance decays and jets similarly affect $v_3(p_T)$ and $v_2(p_T)$ behaviors.

Abstract

Triangular flow $v_3$ of identified and inclusive particles in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV is studied as a function of centrality and transverse momentum within the \textsc{hydjet++} model. The model enables one to investigate the influence of both hard processes and final-state interactions on the harmonics of particle anisotropic flow. Decays of resonances are found to increase the magnitude of the $v_3(p_{\rm T})$ distributions at $p_{\rm T} \geq 2$ GeV/$c$ and shift their maxima to higher transverse momenta. The $p_{\rm T}$-integrated triangular flow, however, becomes slightly weakened for all centralities studied. The resonance decays also modify the spectra towards the number-of-constituent-quark scaling fulfillment for the triangular flow, whereas jets are the main source of the scaling violation at the energies available at the CERN Large Hadron Collider (LHC). Comparison with the corresponding spectra of elliptic flow reveals that resonance decays and jets act in a similar manner on both $v_3(p_{\rm T})$ and $v_2(p_{\rm T})$ behavior. Obtained results are also confronted with the experimental data on differential triangular flow of identified hadrons, ratio $v_3^{1/3}(p_{\rm T}) / v_2^{1/2}(p_{\rm T})$ and $p_{\rm T}$-integrated triangular flow of charged hadrons.