scholarly journals On Extraction of Chemical Potentials of Quarks from Particle Transverse Momentum Spectra in High Energy Collisions

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hong Zhao ◽  
Fu-Hu Liu
Keyword(s):  
Transverse Momentum ◽  
Charged Particles ◽  
High Energy ◽  
Nuclear Collisions ◽  
Chemical Potentials ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
High Energy Collisions ◽  
Positively Charged

We present two methods to extract the chemical potentials of quarks in high energy collisions. The first method is based on the ratios of negatively/positively charged particles, and the temperatures extracted from the transverse momentum spectra of related hadrons are needed. The second method is based on the chemical potentials of some particles, and we also need the transverse momentum spectra of related hadrons. To extract the quark chemical potentials, we would like to propose experimental collaborations to measure simultaneously not only the transverse momentum spectra ofp-,p,K-,K+,π-, andπ+, but also those ofD-,D+,B-, andB+(even those ofΔ++,Δ-, andΩ-) in high energy nuclear collisions.

scholarly journals On Descriptions of Particle Transverse Momentum Spectra in High Energy Collisions

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Fu-Hu Liu ◽  
Ya-Qin Gao ◽  
Hua-Rong Wei
Keyword(s):  
Transverse Momentum ◽  
High Energy ◽  
Emission Source ◽  
Angular Distributions ◽  
Nuclear Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution ◽  
High Energy Collisions ◽  
Bose Einstein

The transverse momentum spectra obtained in the frame of an isotropic emission source are compared in terms of Tsallis, Boltzmann, Fermi-Dirac, and Bose-Einstein distributions and the Tsallis forms of the latter three standard distributions. It is obtained that, at a given set of parameters, the standard distributions show a narrower shape than their Tsallis forms which result in wide and/or multicomponent spectra with the Tsallis distribution in between. A comparison among the temperatures obtained from the distributions is made with a possible relation to the Boltzmann temperature. An example of the angular distributions of projectile fragments in nuclear collisions is given.

scholarly journals The origin of thermal component in the transverse momentum spectra in high energy hadronic processes

2014 ◽  
Vol 23 (12) ◽  
pp. 1450083 ◽  
Author(s):  
Alexander A. Bylinkin ◽  
Dmitri E. Kharzeev ◽  
Andrei A. Rostovtsev
Keyword(s):  
Transverse Momentum ◽  
High Energy ◽  
Relative Strength ◽  
Unruh Effect ◽  
Hadron Spectrum ◽  
Thermal Component ◽  
Momentum Spectra ◽  
Rapidity Gap ◽  
Transverse Momentum Spectra ◽  
High Energy Collisions

The transverse momentum spectra of hadrons produced in high energy collisions can be decomposed into two components: the exponential ("thermal") and the power ("hard") ones. Recently, the H1 Collaboration has discovered that the relative strength of these two components in Deep Inelastic Scattering (DIS) depends drastically upon the global structure of the event — namely, the exponential component is absent in the diffractive events characterized by a rapidity gap. We discuss the possible origin of this effect and speculate that it is linked to confinement. Specifically, we argue that the thermal component is due to the effective event horizon introduced by the confining string, in analogy to the Hawking–Unruh effect. In diffractive events, the t-channel exchange is color-singlet and there is no fragmenting string — so the thermal component is absent. The slope of the soft component of the hadron spectrum in this picture is determined by the saturation momentum that drives the deceleration in the color field, and thus the Hawking–Unruh temperature. We analyze the data on nondiffractive pp collisions and find that the slope of the thermal component of the hadron spectrum is indeed proportional to the saturation momentum.

scholarly journals An Analysis of Transverse Momentum Spectra of Various Jets Produced in High Energy Collisions

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yang-Ming Tai ◽  
Pei-Pin Yang ◽  
Fu-Hu Liu
Keyword(s):  
Transverse Momentum ◽  
Momentum Distribution ◽  
Thermal Model ◽  
High Energy ◽  
Transverse Momentum Distribution ◽  
High Energies ◽  
Model Distribution ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
High Energy Collisions

With the framework of the multisource thermal model, we analyze the experimental transverse momentum spectra of various jets produced in different collisions at high energies. Two energy sources, a projectile participant quark and a target participant quark, are considered. Each energy source (each participant quark) is assumed to contribute to the transverse momentum distribution to be the TP-like function, i.e., a revised Tsallis–Pareto-type function. The contribution of the two participant quarks to the transverse momentum distribution is then the convolution of two TP-like functions. The model distribution can be used to fit the experimental spectra measured by different collaborations. The related parameters such as the entropy index-related, effective temperature, and revised index are then obtained. The trends of these parameters are useful to understand the characteristic of high energy collisions.

scholarly journals Energy-Dependent Chemical Potentials of Light Hadrons and Quarks Based on Transverse Momentum Spectra and Yield Ratios of Negative to Positive Particles

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xing-Wei He ◽  
Feng-Min Wu ◽  
Hua-Rong Wei ◽  
Bi-Hai Hong
Keyword(s):  
Transverse Momentum ◽  
Mass Spectra ◽  
High Energy ◽  
Collision System ◽  
Pp Collisions ◽  
Chemical Potentials ◽  
Momentum Spectra ◽  
Dominant State ◽  
Transverse Momentum Spectra ◽  
Energy Dependent

We describe the transverse momentum spectra or transverse mass spectra of π ± , K ± , p , and p ¯ produced in central gold-gold (Au-Au), central lead-lead (Pb-Pb), and inelastic proton-proton (pp) collisions at different collision energies range from the AGS to LHC by using a two-component (in most cases) Erlang distribution in the framework of multisource thermal model. The fitting results are consistent with the experimental data, and the final-state yield ratios of negative to positive particles are obtained based on the normalization constants from the above describing the transverse momentum (or mass) spectra. The energy-dependent chemical potentials of light hadrons ( π , K , and p ) and quarks ( u , d , and s ) in central Au-Au, central Pb-Pb, and inelastic (pp) collisions are then extracted from the modified yield ratios in which the contributions of strong decay from high-mass resonance and weak decay from heavy flavor hadrons are removed. The study shows that most types of energy-dependent chemical potentials decrease with increase of collision energy over a range from the AGS to LHC. The curves of all types of energy-dependent chemical potentials, obtained from the fits of yield ratios vs. energy, have the maximum at about 3.510 GeV, which possibly is the critical energy of phase transition from a liquid-like hadron state to a gas-like quark state in the collision system. At the top RHIC and LHC, all types of chemical potentials become small and tend to zero at very high energy, which confirms that the high energy collision system possibly changes completely from the liquid-like hadron-dominant state to the gas-like quark-dominant state and the partonic interactions possibly play a dominant role at the LHC.

scholarly journals Initial-State Temperature of Light Meson Emission Source From Squared Momentum Transfer Spectra in High-Energy Collisions

2021 ◽  
Vol 9 ◽  
Author(s):  
Qi Wang ◽  
Fu-Hu Liu ◽  
Khusniddin K. Olimov
Keyword(s):  
Transverse Momentum ◽  
Momentum Transfer ◽  
High Energy ◽  
Emission Source ◽  
Erlang Distribution ◽  
Photon Virtuality ◽  
Initial State ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
High Energy Collisions

The squared momentum transfer spectra of light mesons, π0, π+, η, and ρ0, produced in high-energy virtual photon-proton (γ*p) → meson + nucleon process in electron-proton (ep) collisions measured by the CLAS Collaboration are analyzed by the Monte Carlo calculations, where the transfer undergoes from the incident γ* to emitted meson or equivalently from the target proton to emitted nucleon. In the calculations, the Erlang distribution from a multi-source thermal model is used to describe the transverse momentum spectra of emitted particles. Our results show that the average transverse momentum (⟨pT⟩) and the initial-state temperature (Ti) increase from lower squared photon virtuality (Q2) and Bjorken variable (xB) to higher one. This renders that the excitation degree of emission source, which is described by ⟨pT⟩ and Ti, increases with increasing of Q2 and xB.

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