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The double-differential π ± production cross sections in interactions of charged pions on targets at high momentums are analyzed by using amulticomponent Erlang distribution which is obtained in the framework of amultisource thermal model. The calculated results are compared and found to be in agreement with the experimental data at the incident momentums of 3, 5, 8, and 12GeV/c measured by the HARP Collaboration. It is found that the source contributions to themeanmomentumof charged particles and to the distributionwidth of particlemomentums decreasewith increase of the emission angle, and the source number and temperature do not show an obvious dependence on the emission angle of the considered particle [ABSTRACT FROM AUTHOR]

Based on the (pseudo)rapidity distribution of final-state particles produced in proton-proton (pp) collisions at high energy, the probability distributions of momenta, longitudinal momenta, transverse momenta (transverse masses), energies, velocities, longitudinal velocities, transverse velocities, and emission angles of the considered particles are obtained in the framework of a multisource thermal model. The number density distributions of particles in coordinate and momentum spaces and related transverse planes, the particle dispersion plots in longitudinal and transverse coordinate spaces, and the particle dispersion plots in transverse momentum plane at the stage of freeze out in high energy pp collisions are also obtained. [ABSTRACT FROM AUTHOR]

Thetransverse momentum spectrums of final-state products produced in nucleus-nucleus and proton-proton collisions at different center-of-mass energies are analyzed by using a multicomponent Erlang distribution and the Lévy distribution. The results calculated by the two models are found in most cases to be in agreement with experimental data from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). The multicomponent Erlang distribution that resulted from a multisource thermalmodel seems to give a better description as comparedwith the Lévy distribution. Thetemperature parameters of interacting system corresponding to different types of final-state products are obtained. Light particles correspond to a low temperature emission, and heavy particles correspond to a high temperature emission. Extracted temperature from central collisions is higher than that from peripheral collisions. [ABSTRACT FROM AUTHOR]

In the framework of amultisource thermalmodel, the transversemomentumdistributions of charged particles produced in nucleusnucleus (A-A) and deuteron-nucleus (d-A) collisions at relativistic heavy ion collider (RHIC) energies are investigated by a twocomponent revised Boltzmann distribution. The calculated results are in agreement with the PHENIX experimental data. It is found that the source temperature increases obviously with increase of the particle mass and incident energy, but it does not show an obvious change with the collision centrality. Then, the values of chemical potentials for up, down, and strange quarks can be obtained fromthe antiparticle to particle yield ratios in a wide transverse momentum range. The relationship between the chemical potentials of quarks and the transverse momentum with different centralities is investigated, too. [ABSTRACT FROM AUTHOR]

The transverse momentum and pseudorapidity distributions of charged particles produced in Pb-Pb collisions with different centrality intervals at center-of-mass energy per nucleon pair √sNN = 2.76TeV have been analyzed by using the improved multisource thermal model in which the whole interacting system and then the sources are described by the Tsallis statistics. The modelling results are in agreement with experimental data of the ALICE Collaboration. The rapidity distributions of charged particles are obtained according to the extracted parameter values.The shapes of interacting events (the dispersion plots of charged particles) are given in the momentum, rapidity, velocity, and coordinate spaces. Meanwhile, the event shapes in different spaces consisted by different transverse quantities and longitudinal quantities are presented. [ABSTRACT FROM AUTHOR]

Pseudorapidity distributions of charged particles produced in proton-proton (p-p) or proton-antiproton (p-p) collisions over an energy range from 0.053 to 7 TeV are studied by using the four-component Landau hydrodynamic model. The results calculated by the model are in agreement with the experimental data of the UA5, PHOBOS, UA1, P238, CDF, ALICE, and CMS Collaborations which present orderly fromlow to high energies. According to the distribution widths of different components, the values and some features of square speed of sound parameter c2s for "participant" and "spectator" quark components are obtained. It is shown that the speed of sound for "participant" quark components agrees approximately with that for "spectator" quark components in the error ranges. The present work is useful for studying nucleus-nucleus collisions in the related energy range. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Two-particle azimuthal correlations are studied in the framework of a multisource thermal model. Each source is assumed to producemany particles. Each particle pairmeasured in final state is considered to be produced at two emission points (subsources) in a single or two sources. The first emission point corresponds to the production of "trigger" particle and the second one corresponds to that of "associated" particle. There are oscillations and other interactions between the two emission points. In the rest frame of the "associated" particle's emission point, the oscillations and other interactions cause the momentum of the "trigger" particle to depart from the original value.The modelling results are in agreement with the experimental data of proton-lead (p-Pb) collisions at √SNN = 5.02 TeV, one of the Large Hadron Collider energies, measured by the ALICE and ATLAS Collaborations. [ABSTRACT FROM AUTHOR]

We discuss the dependence of elliptic flow on transverse momentum and number of participating nucleons in the framework of a multi-source model, and argue that the geometry of an initial overlap region of interaction determines the measured azimuthal asymmetry. With the help of v2(PT) fitting, the participant nucleon number at a fixed impact parameter is calculated by a geometrical picture of the participant-spectator model. In the combined framework of the two models, our results are approximately in agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Transverse momentum distributions of final-state particles produced in soft process in proton-proton (pp) and nucleus-nucleus (AA) collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies are studied by using a multisource thermal model. Each source in the model is treated as a relativistic and quantum ideal gas. Because the quantum effect can be neglected in investigation on the transverse momentum distribution in high energy collisions, we consider only the relativistic effect. The concerned distribution is finally described by the Boltzmann or two-component Boltzmann distribution. Our modeling results are in agreement with available experimental data. [ABSTRACT FROM AUTHOR]

In the combined framework of a multisource and participant-spectator model, we study the elliptic flow as a function of transverse momentum and number of participating nucleons in √SNN = 200GeV Au-Au and √SNN = 2.76 TeV Pb-Pb collisions and argue that the geometry of the initial overlap region in the collisions determines the experimentally measured azimuthal asymmetries. Our results are approximately in agreement with the data from PHENIX and ALICE collaborations. [ABSTRACT FROM AUTHOR]

The inclusive particle productions in proton-proton (ρρ) and deuton-gold (d+Au) collisions at forward rapidity at the Relativistic Heavy Ion Collider (RHIC) energy are studied in the framework of the color glass condensate (CGC) theory by using two different initial conditions: AAMQS (Albacete-Armesto-Milhano-Quiroga-Salgado) and quartic action. Then, the results obtained by the two different initial conditions in illustrating the effect of valence color charges in high-energy proton-nucleus (ρA) collisions at forward energy are compared. Meanwhile, the inclusive particle productions in ρA collisions at forward rapidity at the Large Hadron Collider (LHC) energies are predicted. The main dynamical input in our calculations is the use of solutions of the running coupling Balitsky-Kovchegov equation tested in electron-proton (eρ) collision data. Particle production is computed via the hybrid formalisms to obtain spectra and yields. These baseline predictions are useful for testing the current understanding of the dynamics of very strong color fields against the upcoming LHC data. [ABSTRACT FROM AUTHOR]

In high energy collisions, one usually needs to give a conversion between the particle rapidity and pseudorapidity distributions. Currently, two equivalent conversion formulas are used in experimental and theoretical analyses. An investigation in the present work shows that the two conversions are incomplete. Then, we give a revision on the current conversion between the particle rapidity and pseudorapidity distributions. [ABSTRACT FROM AUTHOR]

The multisource thermal model is used in this paper to analyze the antiproton (ρ) production process in high-energy proton-carbon (ρ-C) collisions. The transverse momentum, Feynman variable, and rapidity distributions of antiprotons in the nucleon-nucleon center-of-mass system are calculated by using the model. The modeling results are compared and found to be in agreement with the experimental data measured by the NA49 Collaboration at 158GeV/c beam momentum. As a parameter, the nuclear temperature of interacting system extracted from the antiproton spectrum is estimated to be about 150MeV. [ABSTRACT FROM AUTHOR]

In framework of combing the participant-spectator model and the Landau hydrodynamic model, the pseudorapidity distributions of charged particles produced in heavy-ion (or nucleus-nucleus) collisions at RHIC and LHC energies are described by a modified Landau hydrodynamic model, where the Landau hydrodynamic model is applied to the target/projectile spectators and the target/projectile participants, respectively. The modeling results are in agreement with the PHOBOS and ALICE experimental data. Then, the values of square speed of sound (c2s ) for the participants and spectators can be obtained from the widths of charged particle pseudorapidity distributions. Some features of c2s for different centralities and center-of-mass energies are obtained too. [ABSTRACT FROM AUTHOR]

We investigate the dependence of elliptic flows v2 on transverse momentum PT for charged and strange hadrons produced in Cu-Cu collisions by using a multi-source thermal model, which includes the interaction contribution of the emission sources. The magnitude of the expansion is denoted by a expansion factor k. Our calculated results are approximately in agreement with the experimental data in Cu-Cu collisions at vsNN = 62.4 and 200 GeV, measured by the STAR Collaboration. It is found that the expansion factor increases linearly with the impact parameter from the most central (0-10%) to mid-peripheral (40-50%) collisions. [ABSTRACT FROM AUTHOR]

The multisource thermal model is revised for relativistic and quantum situations. It is shown that the quantum effect can be neglected due to a very small result. The distributions of particle momenta, momentum components, transverse momenta, kinetic energies, and velocities in both the classical and relativistic situations are presented to give comparisons. [ABSTRACT FROM AUTHOR]

The dependences of elliptic flows on transverse momentum for identified particles produced in nucleus-nucleus collisions at high energy are studied by using a multi source ideal gas model that describes the distribution of transverse momenta as a Rayleigh-like distribution. The experimental results of Au-Au collisions at √s = 200A and 62.4A GeV and Cu-Cu collisions at √s = 200A GeV, measured by the STAR and PHENIX collaborations, are well described by this model. [ABSTRACT FROM AUTHOR]

Multiplicity distributions of projectile fragments emitted in gold-emulsion (Au--Em) collisions at 10.7AGeV are reported. The projectile lithium and heavier fragments show an exponential multiplicity distribution. The projectile helium and hydrogen fragments show a single peak and a twopeak multiplicity distributions, respectively. These distributions are studied using a two-phase model. [ABSTRACT FROM AUTHOR]

The pseudorapidity distributions of charged particles produced in $p\bar p$ annihilations and AA collisions at high energies are investigated by using a revised thermalized cylinder model. The Monte Carlo calculated results are compared and found to be in good agreement with the experimental data of $p\bar p$ annihilations at center-of-mass energy $\sqrt{s}=900$, 546, 200, and 53 GeV, Au–Au collisions at $\sqrt{s}=200 {\rm A}$ and 130 A GeV, and Pb–Pb collisions at $\sqrt{s}=17.3 {\rm A GeV}$. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rapidity and transverse-momentum distributions of particles produced in central Pb-Pb collisions at high energy are analyzed by the thermalized cylinder model. The calculated results are compared and found to be in agreement with the recent experimental data of the NA49 Collaboration. [ABSTRACT FROM AUTHOR]

Three isotropic emission fireballs are used to describe the rapidity (or pseudorapidity) and transverse momentum distributions of negatively charged particles produced in nucleus-nucleus collisions at high energy. The calculated results are compared and shown to be in agreement with the experimental data of [SUP16]O-Au, [SUP32]S-S, and [SUP32]S-Ag collisions at 200A GeV. [ABSTRACT FROM AUTHOR]

The pseudorapidity (rapidity) distributions of particles produced in high-energy collisions are analyzed using the revised thermalized cylinder model. The calculated results are compared and found to be in agreement with the experimental data of pp collision and e[SUP+]e[SUP-] annihilation. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe the transverse momentum spectra of π±, K±, p, and produced in proton–proton (pp) collisions at different collision energies by using a Tsallis–Pareto-type function, and obtain the yield ratios, kπ, kK, and kp, of negative to positive particles from the fitting results of transverse momentum spectra and the extracted normalization constants. The transverse momentum dependent and energy dependent chemical potentials of light hadrons (π, K, and p) and quarks (u, d, and s) in pp collisions are then extracted successively from the yield ratios. The six types of transverse momentum dependent chemical potentials show the trend of being close to zero in low-pT region and away from zero in high-pT region. Meanwhile, the energy dependent chemical potentials seem to decrease slightly with the increase of the collision energy, and the limiting values of the six types of chemical potentials are zero at very high energy in pp collisions, which confirms that the partonic interactions possibly play an important role at RHIC and LHC, especially at LHC. [ABSTRACT FROM AUTHOR]

The transverse momentum (pT) and pseudorapidity (η) spectra of charged particles produced in proton–proton (pp) and lead–lead (Pb-Pb) collisions at the Large Hadron Collider (LHC) are described by a hybrid model. In the model, the pT spectrum is described by a two-component distribution which contains an inverse power-law suggested by quantum chromodynamic calculus and an Erlang distribution resulted from a multisource thermal model. The η spectrum is described by a Gaussian rapidity (y) distribution resulted from the Landau hydrodynamic model and the two-component pT distribution, where the conversion between y and η is accurately considered. The modelling results are in agreement with the experimental data measured by the ATLAS Collaboration in pp collisions at center-of-mass energy TeV and in Pb–Pb collisions at center-of-mass energy per nucleon pair TeV. Based on the parameter values extracted from pT and η or y spectra, the event patterns or particle scatter plots in three-dimensional velocity and momentum spaces are obtained. [ABSTRACT FROM AUTHOR]

It is shown that the acoustic scaling patterns of anisotropic flow for different event shapes at a fixed collision centrality (shape-engineered events), provide robust constraints for the event-by-event fluctuations in the initial-state density distribution from ultrarelativistic heavy ion collisions. The empirical scaling parameters also provide a dual-path method for extracting the specific shear viscosity of the quark-gluon plasma (QGP) produced in these collisions. A calibration of these scaling parameters via detailed viscous hydrodynamical model calculations, gives estimates for the plasma produced in collisions of Au + Au () and Pb + Pb (). The estimates are insensitive to the initial-state geometry models considered. [ABSTRACT FROM AUTHOR]