The transverse momentum distributions of final-state particles produced in collisions at high en-ergies are studied by using a two-component Rayleigh-like distribution.This representation is based on Liu's multisource ideal gas model which describes protons and fragments in high energy nucleus-nucleus collisions.The calculated results are in good agreement with the experimental data of Au-Au,Cu-Cu,d-Au,and pp collisions at the relativistic heavy ion collider energies.The experimental particle momentum distributions of p-Be collisions at 6.4,12.3,and 17.5 GeV/c,as well as Au-Au collisions at 1.5 AGeV are well described by a model based on a single Rayleigh-like distribution of particle transverse momenta.
Two-particle (two-fragment) azimuthal correlation functions are studied by using a simple formula which describes uniformly azimuthal distributions of final-state charged particles and nuclear fragments. This formula is obtained in the framework of a multi-source thermal model (or multi-source ideal gas model). The calculated results are compared and found to be in agreement with the experimental data of charged hadrons and nuclear fragments in nucleus-nucleus collisions at intermediate and high energies.
The transverse momentum distributions of final-state particles produced in nucleus-nucleus (AA), proton-nucleus (pA), and proton-proton (pp) collisions at high energies are investigated using a multisource ideal gas model. Our calculated results show that the contribution of hard emission can be neglected in the study of transverse momentum spectra of charged pions and kaons produced in Cu-Cu collisions at √ sNN=22.5 GeV. And if we consider the contribution of hard emission, the transverse momentum spectra of p and pˉ produced in Cu-Cu collisions at √ sNN=22.5 GeV, K0s produced in Pb-Pb collisions at 158 A GeV, J/ψ particles produced in p-Pb collisions at 400 GeV and π+, K+, p produced in proton-proton collisions at √ s=200 GeV, can be described by the model, especially in the tail part of spectra.
Multiparticle azimuthal correlations in central nucleus-nucleus collisions at high energy are described by a simple formula. The calculated results are in agreement with the experimental data of carbon and oxygen induced interactions at Dubna energy. The comparison between the calculated results and experimental data shows that particles are emitted isotropically in the rest frame of the emission sources, and the emission sources have movements in momentum space.
The transverse mass spectra of protons, pions, kaons, Lambda and Antilambda produced in central nucleus-nucleus collisions at high energies are described by using one-temperature and two-temperature emission pictures. The calculated results are compared and found to be in good agreement with the experimental data of the E895, E866 and E917 Collaborations measured in central Au-Au collisions at the Alternating Gradient Synchrotron (AGS) energies and the NA49 Collaboration measured in central Pb-Pb collisions at the Super Proton Synchrotron (SPS) energies. It is demonstrated that the transverse mass distributions of protons, kaons, Lambda and Antilambda, except for Lambda hyperons produced in central Pb-Pb collisions at 158 A GeV, can be described by using the one-temperature emission picture, and for pions, we need to use the two-temperature emission picture.
Various flow phenomena of black particles(b-particles) and grey particles(g-particles) produced in magnesium-emulsion(Mg-Em) collisions at 4.5 A GeV/c are reported.These flows are directed and elliptic transverse flows(v1 and v2) related by the azimuthal angle(),directed and elliptic reaction plane flows(vR1 and vR2) related by the projected angle(ψ) on the reaction plane,and directed and elliptic polar direction flows(vP1 and vP2) related by the polar angle(■).We extract absolute flows as the direct experimental values minus the isotropic theoretical values.The dependence of the various flows on the target particle multiplicity and on the angles(■,,ψ) is investigated.Our results show that the dependence of b-particle flows on the target size is obvious and for heavy targets the dependence on target particle multiplicity is slight.Compared with b-particles,g-particles have a slight dependence on the target size and target particle multiplicity.
