59422650
Transverse Momentum and Pseudorapidity Distributions of Charged Particles and Spatial Shapes of Interacting Events in Pb-Pb Collisions at 2.76 TeV
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  TeV 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.
54930891
Chemical Potentials of Quarks Extracted from Particle Transverse Momentum Distributions in Heavy Ion Collisions at RHIC Energies
In the framework of a multisource thermal model, the transverse momentum distributions of charged particles produced in nucleus-nucleus (A-A) and deuteron-nucleus (d-A) collisions at relativistic heavy ion collider (RHIC) energies are investigated by a two-component 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 from the 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.
56154903
Transverse Momentum Distributions of Final-State Particles Produced in Soft Excitation Process in High Energy Collisions
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.
121546377
Dependences of charged particle pseudorapidity distributions on impact parameter and center-of-mass energy in nucleus–nucleus collisions at relativistic energies
The centrality and rapidity dependence of charged particles over a wide range of center-of-mass energy are analyzed. In this framework of participant-spectator model, the interacting system of nucleus–nucleus collisions at relativistic energies is divided into four parts (sources): target spectator, target participant, projectile participant and projectile spectator. Each source is treated by using a revised Landau model. The pseudorapidity distributions calculated by four-component Landau model are found to be in agreement with experimental data of the PHOBOS and ALICE collaborations. The distribution height is mainly determined by effective nucleon number and center-of-mass energy; and the distribution width being measured by the revised width in the Landau model and the sources rapidity shifts. Furthermore, we have found two empirical relations for projectile-participant and projectile-spectator (pseudo)rapidity as functions of the center-of-mass energy.
124273608
Strange Quark Matter and Strangelets in a Strong Magnetic Field
We study the stability properties of magnetized strange quark matter and strangelets under a strong magnetic field in the MIT bag model. The free energy per baryon of strange quark matter feels a great influence from the magnetic held. At the held strength about 1017 G, the magnetized strange quark matter becomes more stable. Considering the finite size effect, the magnetic influence on strangelets becomes complicated. For a given magnetic held, there exists a critical baryon number, below which the magnetized strangelets have lower energy than the non-magnetized strangelets. For the held strength of 5 × 1017 G, the critical baryon number is Ac ~ 100. Generally, the critical baryon number increases with the decreasing external magnetic held. When the held strength is smaller than 1017 G, the critical baryon number goes up to Ac ~ 105. The stable radius, electric charge, and quark flavor fractions of magnetized strangelets are shown.
120288217
Comparing two-Boltzmann distribution and Tsallis statistics of particle transverse momentums in collisions at LHC energies
The transverse momentum distributions of final-state particles produced in collisions at energies available at the Large Hadron Collider (LHC) are studied by using the two-Boltzmann distribution and Tsallis statistics. Experimental distributions described by the two-Boltzmann distribution can be described by the Tsallis statistics. The two-temperature emission described by the two-Boltzmann distribution reflects temperature fluctuation of interacting system. The Tsallis statistics can describe the temperature fluctuation and the degree of non-equilibrium. The results calculated by the two-Boltzmann distribution and the Tsallis statistics are in agreement with the experimental data available at the LHC energies. In some cases, the two-Boltzmann distribution degenerates to (single) Boltzmann distribution.
124621634
Thermal emission of strange particles in central Pb-Pb collisions at the SPS energy
115903813
Angular Distributions of Target Fragments in Magnesium-Emulsion Collisions at High Energy
122169808
Pseudorapidity distributions of charged particles in $p-\bar{p}$ or $p-p$ collisions at high energies and predictions at ultrahigh energies
Pseudorapidity distributions of charged particles produced in $p\ensuremath{-}\mathrm{p\ifmmode \bar{}\else \={}\fi{}}$ or $p\ensuremath{-}p$ collisions at different energies were reported by the UA5, UA1, P238, CDF, and ALICE collaborations. A multisource ideal gas model is used to fit the experimental data in this paper. According to the parameter values obtained from fitting the data, we find different linear relationships between different parameters and logarithmic center-of-mass energy. A prediction for the pseudorapidity distributions of charged particles produced in $p\ensuremath{-}\mathrm{p\ifmmode \bar{}\else \={}\fi{}}$ or $p\ensuremath{-}p$ collisions at the higher Large Hadron Collider energies is given.
122895317
Dependence of charged particle pseudorapidity distributions on centrality and energy in p(d)A collisions at high energies
The pseudorapidity distributions of charged particles produced in deuteron-gold (d-Au) and proton-emulsion (p-Em) collisions at high energies are studied in the framework of the two-cylinder model. The experimental results of nuclear reactions induced by protons and deuterons [p(d)A collisions] can be simply described by this model. The dependencies of parameter values on centrality for d-Au collisions and on nucleon-nucleon center-of-mass energy for p-Em collisions are obtained. The formula obtained by this model is a unified formula in the description of (pseudo)rapidity distributions of final-state particles produced in different interactions over an energy range from intermediate accelerator energy to ultrahigh cosmic-ray energy.
121221082
Formulation of particle pseudo-rapidity (rapidity) distribution in high-energy pp collision and e+e- annihilation
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+e annihilation. PACS Nos.: 13.85-t, 13.75-n, 13.85Hd, 13.65+i