Initial- and Final-State Temperatures of Emission Source from Differential Cross-Section in Squared Momentum Transfer in High-Energy Collisions

Abstract

The differential cross-section in squared momentum transfer of ρ , ρ 0 , ω , ϕ , f 0 980 , f 1 1285 , f 0 1370 , f 1 1420 , f 0 1500 , and J / ψ produced in high-energy virtual photon-proton ( γ ∗ p ), photon-proton ( γ p ), and proton-proton ( p p ) collisions measured by the H1, ZEUS, and WA102 Collaborations is analyzed by the Monte Carlo calculations. In the calculations, the Erlang distribution, Tsallis distribution, and Hagedorn function are separately used to describe the transverse momentum spectra of the emitted particles. Our results show that the initial- and final-state temperatures increase from lower squared photon virtuality to a higher one and decrease with the increase of center-of-mass energy.

Excitation functions of related temperatures of η and η0 emission sources from squared momentum transfer spectra in high-energy collisions

“…In this paper, we select the squared momentum transfer spectra at different center-of-mass energy W and incident photon energy E γ to analyze. Based on the literature [24], we learned that W = √ s = −(P 1 + P 2 ) 2 . Let Q 2 and x be the squared photon virtuality and Bjorken scaling variable, we have…”

“…T i , a useful tool for describing the excitation degree of system, represents the temperature of system or emission source at the initial-stage of collisions [24]. This initialstage refers to a very short stage after thermalization at the beginning of collisions.…”

Thermal freeze-out parameters and pseudo-entropy from charged hadron spectra in high energy collisions

“…In order to obtain the thermal or kinetic (or kinematic) freeze-out temperature T 0 and the average transverse flow velocity β t [48][49][50][51], one may fit firstly the p T spectra of particles to obtain the effective temperature T , and the average p T ( p T ) and average energy (m) of particles in the source rest frame using the Monte Carlo algorithm [52][53][54][55][56][57][58]. Then, one may extract the intercept as T 0 in the linear relation of T versus m 0 , and further obtain the slope as β t in the linear relation of p T versus m.…”

Excitation Functions of Related Temperatures of η and η0 Emission Sources from Squared Momentum Transfer Spectra in High-Energy Collisions

“…As a useful tool for describing the excitation degree of the system, T i represents the temperature of the system or emission source at the initial-stage of collisions [24,25]. This initial-stage refers to a very short stage after the thermalization at the beginning of collisions.…”