Heavy dilepton in nucleus nucleus collision at LHC energy

TL;DR

This paper investigates tau lepton pair production in lead-lead collisions at LHC energies, highlighting the dominance of Drell-Yan processes and the potential to detect quark-gluon plasma signals in the 4-6 GeV mass range.

Contribution

It provides a detailed analysis of tau lepton pair production mechanisms and their yields in heavy-ion collisions at LHC, emphasizing the potential to observe QGP signatures.

Findings

Drell-Yan process dominates tau pair production from 4 to 20 GeV.

Tau pair yield ratio exceeds unity in 4-6 GeV range, indicating QGP signals.

Thermal contributions are small compared to Drell-Yan at LHC energies.

Abstract

We present a study of $\tau^+ \tau^-$ lepton pair production in Pb + Pb collisions at $\sqrt{s_{NN}}$ = 5.5 TeV. The larger mass of tau lepton compared to electron and muon leads to considerably small hadronic contribution to the $\tau^+ \tau^-$ pair invariant mass (M) distribution relative to the production from thermal partonic sources. The quark-antiquark annihilation processes via intermediary virtual photon, Z and Higgs bosons have been considered for the tau lepton production. The contribution from Drell-Yan process is found to dominate over thermal yield for $\tau^+ \tau^-$ pair mass from 4 to 20 GeV at the LHC energy. We also present the ratio of $\tau$ lepton pair yields for nucleus-nucleus collisions relative to yields from p + p collisions scaled by number of binary collisions at LHC energies as a function $\tau$ lepton pair inavariant mass. The ratio is found to be significantly above unity for the mass range 4 to 6 GeV. This indicates the possibility of detecting $\tau^+ \tau^-$ pair from quark gluon plasma (QGP) in the mass window 4 to 6 GeV.