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

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.

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Li-Li Li ◽  
Fu-Hu Liu ◽  
Muhammad Waqas ◽  
Muhammad Ajaz

We analyzed the transverse momentum spectra of positively and negatively charged pions (π+ and π−), positively and negatively charged kaons (K+ and K−), protons and antiprotons (p and p¯), as well as ϕ produced in mid-(pseudo)rapidity region in central nucleus–nucleus (AA) collisions over a center-of-mass energy range from 2.16 to 2760 GeV per nucleon pair. The transverse momentum of the considered particle is regarded as the joint contribution of two participant partons which obey the modified Tsallis-like transverse momentum distribution and have random azimuths in superposition. The calculation of transverse momentum distribution of particles is performed by the Monte Carlo method and compared with the experimental data measured by international collaborations. The excitation functions of effective temperature and other parameters are obtained in the considered energy range. With the increase of collision energy, the effective temperature parameter increases quickly and then slowly. The boundary appears at around 5 GeV, which means the change of reaction mechanism and/or generated matter.


2014 ◽  
Vol 23 (12) ◽  
pp. 1450083 ◽  
Author(s):  
Alexander A. Bylinkin ◽  
Dmitri E. Kharzeev ◽  
Andrei A. Rostovtsev

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hong Zhao ◽  
Fu-Hu Liu

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.


2011 ◽  
Vol 20 (07) ◽  
pp. 1616-1622
Author(s):  
REDAMY PEREZ-RAMOS

In this paper, we report our results on charged hadron multiplicities of heavy quark initiated jets produced in high energy collisions. After implementing the so-called dead cone effect in QCD evolution equations, we find that the average multiplicity decreases significantly as compared to the massless case. Finally, we discuss the transverse momentum distribution of light quark initiated jets and emphasize the comparison between our predictions and CDF data.


2021 ◽  
Vol 9 ◽  
Author(s):  
Qi Wang ◽  
Fu-Hu Liu ◽  
Khusniddin K. Olimov

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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