Charged particle elliptic flow in p+p collisions at LHC energies in a transport model PACIAE

TL;DR

This study uses the PACIAE transport model to simulate charged particle elliptic flow in proton-proton collisions at LHC energies, revealing how flow varies with energy, geometry, and parton interactions.

Contribution

It introduces a novel application of the PACIAE model to analyze elliptic flow in pp collisions, incorporating transverse ellipsoid geometry and rescattering effects.

Findings

Elliptic flow increases with energy up to 7 TeV and then saturates.

Enhanced parton cross section can produce a flow of about 0.025 at 7 TeV.

Flow depends on the geometric distribution and rescattering parameters.

Abstract

The parton and hadron cascade model PACIAE based on PYTHIA was used to investigate the charged particle elliptic flow in minimum bias pp collisions at the LHC energies. The strings were distributed randomly in the transverse ellipsoid of the pp collision system with major axis of $R$ (proton radius) and minor axis of $R(1-\xi)$ before parton rescattering. The charged particle elliptic flow as a function of the random number $\xi$ and transverse momentum $p_T$ were investigated. The calculated $v_2/\epsilon$ as a function of reaction energy increases monotonously with increasing reaction energy up to $\sqrt{s}\sim$7 TeV and then turns to saturation. With the parton-parton cross section enlarges three times in parton rescattering, the rapidity integrated charged particle elliptic flow may reach 0.025 at $p_T \sim$2 GeV/c in the minimum bias pp collisions at $\sqrt{s}$=7 TeV.