Investigating the Bulk Properties of Charged Particles in Different $\eta$ Bins Using a Modified Tsallis Model

TL;DR

This study analyzes charged particle distributions in proton-proton collisions at various energies and pseudorapidities using a modified Tsallis model, revealing how thermal and dynamic parameters vary with pseudorapidity and energy.

Contribution

It introduces a modified Tsallis model incorporating mean transverse flow velocity to accurately describe $p_T$ distributions across different $ ext{pp}$ collision energies and pseudorapidity regions.

Findings

Parameters like $T_0$, $eta_T$, and $raket{p_T}$ decrease with increasing $ ext{eta}$.

The non-extensivity parameter $q$ increases with $ ext{eta}$, indicating closer thermal equilibrium mid-$ ext{eta}$.

Model fits show high agreement with experimental data across all $p_T$ ranges.

Abstract

This paper presents a comprehensive analysis of the double-differential $p_T$ distributions of charged particles in twelve distinct pseudorapidity regions of equal width in $pp$ collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV. Utilizing the modified Tsallis function with mean transverse flow velocity, our study demonstrates a very good agreement between experimental data and the model employed. The fit quality is consistently high across all $p_T$ ranges, as assessed by Data/Fit panels accompanying each plot. Extracted parameters, including kinetic freeze-out temperature ($T_0$), transverse flow velocity ($\beta_T$), non-extensivity parameter ($q$) and mean transverse momentum $\langle p_T \rangle$ dependencies are shown on pseudorapidity ($\eta$) and collision energy ($\sqrt{s}$). $T_0$, $\beta_T$ and $\langle p_T \rangle$ exhibit a decreasing trend with increasing $\eta$ due to lower in energy transfer along high $\eta$ regions, while they show a heightened sensitivity to $\sqrt{s}$. $q$ increases with $\eta$, indicating a closer thermal equilibrium in mid-$\eta$ particles. The paper also explores correlations among these parameters, emphasizing relationships between $T_0$, $\beta_T$, $q$ and $\langle p_T \rangle$. Our study provides valuable insights into the thermal and dynamic characteristics of high-energy proton-proton collisions, contributing to the broader understanding of the bulk properties of nuclear matter produced in these interactions.