123919722
Multiplicity distributions of shower particles and target fragments in 7Li–Em collisions at 3 A GeV/c
Multiplicity distributions of shower particles and target fragments in 7Li–Em (emulsion) collisions at 3 A GeV/c are experimentally studied. In the framework of the multisource thermal model, the multicomponent Erlang distribution is used to describe the experimental multiplicity distributions of shower particles, grey fragments, black fragments, and heavily ionized fragments. The correlations between these multiplicities are experimentally reported. With the increase of impacting centrality (or the target fragment multiplicity), a saturation phenomenon for shower particle multiplicity is observed in the experiment.
122076971
ANGULAR DISTRIBUTIONS OF TARGET BLACK FRAGMENTS IN NUCLEUS NUCLEUS COLLISIONS AT HIGH ENERGY
The experimental results of space, azimuthal, and projected angular distributions of target black fragments produced in silicon-emulsion collisions at 4.5A GeV/c (the Dubna energy) are reported. A multi-source ideal gas model is suggested to describe the experimental angular distributions. The Monte Carlo calculated results are in agreement with the experimental data.
118607664
Singly and Doubly Charged Projectile Fragments in Nucleus-Emulsion Collisions at Dubna Energy in the Framework of the Multi-Source Model *
The multiplicity distributions of projectile fragments emitted in interactions of different nuclei with emulsion are studied by using a multi-source model. Our calculated results show that the projectile fragments can be described by the model and each source contributes an exponential distribution. As the weighted sum of the folding result of many exponential distributions, a multi-component Erlang distribution is used to describe the experimental data. The relationship between the height (or width) of the distribution and the mass of the incident projectile, as well as the dependence of projectile fragments on target groups, are investigated too.
120712528
Alpha emission in krypton–emulsion collisions at 1.7A GeV
Abstract The multiplicity and transverse momentum distributions of alpha projectile fragments emitted in nucleus–nucleus collisions at high energies are investigated. The results calculated by the two-source model are in agreement with the experimental data of krypton–emulsion collisions at 1.7 A  GeV.
115903813
Angular Distributions of Target Fragments in Magnesium-Emulsion Collisions at High Energy
118846232
RAPIDITY AND TRANSVERSE-MOMENTUM DISTRIBUTION OF PRODUCED PARTICLES IN E+ E- ANNIHILATION AND PP COLLISION AT HIGH ENERGY
118540594
Energy and Centrality Dependence of Chemical Freeze-out Thermodynamics parameters
energy and somehow saturates at certain values of Tch in collisions near √ sNN=10 GeV, indicating the limiting temperature in hadronic interactions; meanwhile the baryon chemical potential µB decrease with the collision energy. The saturation temperature is also found to be dependent on partonic interaction. At a given collision energy, it is found that both Tch and µB decrease towards more peripheral collisions in the grand canonical approach. The energy and centrality dependence of other chemical freeze-out parameters, strangeness chemical potential µS , strangeness undersaturation factor S , and the volume of the fireball V are also presented in this paper. The chemical potential ratio µs/µB is also compared with lattice QCD calculation. The AMPT default model gives better descriptions on both the particle yields and the chemical freeze-out parameters than those from the AMPT string-melting model.
122934588
Multi-component Erlang distribution of final-state particles produced in high energy collisions
A unified formula on multiplicity distributions of final-state particles is studied in this paper to describe a variety of experimental data including multiplicity, mass, transverse mass, excitation energy, transverse energy, and transverse momentum distributions. It is assumed that the sources of final-state particles are subjected to the multi-source thermal model and the contributions of sources meet the Erlang distribution. Further the validity of the unified formula in descriptions of different distributions is tested. Experimental data of proton-antiproton $$(p\overline{p}),$$ positron–proton (e+p), electron-proton (e−p), and nucleus-nucleus (AA) collisions are analyzed and found that the distributions of mentioned quantities can be described by the multi-component Erlang distribution.
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.
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.
1752055
On transverse momentum event–by–event fluctuations in string hadronic models
Abstract. Transverse momentum event–by–event fluctuations are studied within the string–hadronic model of high energy nuclear collisions, LUCIAE. Data on non–statistical $p_T$ fluctuations in p+p interactions are reproduced. Fluctuations of similar magnitude are predicted for nucleus–nucleus collisions, in contradiction to the preliminary NA49 results. The introduction of a string clustering mechanism (Firecracker Model) leads to a further, significant increase of $p_T$ fluctuations for nucleus–nucleus collisions. Secondary hadronic interactions, as implemented in LUCIAE, cause only a small reduction of $p_T$ fluctuations.