Statistical Behavior of Lepton Pair Spectrum in Drell-Yan Process and Signal from Quark-Gluon Plasma in High Energy Collisions

TL;DR

This paper analyzes the transverse momentum spectra of lepton pairs in Drell-Yan processes across various high-energy collisions using statistical models, revealing parameter variations with energy and invariant mass.

Contribution

It introduces a statistical approach with specific probability density functions to model and analyze lepton pair spectra in Drell-Yan processes, providing insights into their energy dependence.

Findings

Fit results agree with experimental data

Parameter variation laws as functions of energy and mass

Statistical description of the Drell-Yan process

Abstract

We analyze the transverse momentum ($p_{T}$) spectra of lepton pairs ($\ell\bar \ell$) generated in the Drell-Yan process, as detected in proton-nucleus (pion-nucleus) and proton-(anti)proton collisions by ten collaborations over a center-of-mass energy ($\sqrt{s_{NN}}$ or $\sqrt{s}$ if in a simplified form) range from $\sim20$ GeV to above 10 TeV. Three types of probability density functions (the convolution of two L\'{e}vy-Tsallis functions, the two-component Erlang distribution, and the convolution of two Hagedorn functions) are utilized to fit and analyze the $p_{T}$ spectra. The fit results are approximately in agreement with the collected experimental data. Consecutively, we obtained the variation law of related parameters as a function of $\sqrt{s}$ and invariant mass ($Q$). In the fit procedure, a given L\'{e}vy-Tsallis (or Hagedorn) function can be regarded as the probability density function of transverse momenta contributed by a single quark ($q$) or anti-quark ($\bar q$). The Drell-Yan process is then described by the statistical method.