Multi-production Of Final-state Particles In Proton-proton Collisions At RHIC And LHC Energies

High energy collisions are one of the most important areas in particle and nuclear physics. It is mainly to study the evolution of dynamics process, as well as phenomena and laws in collisions. Quantum Chromodynamics (QCD) is constantly improving and developing in the study. QCD predicted that a new phase of matter named quark-gluon plasma is expected to produce in high energy nucleus-nucleus collisions. One has been through the analyses of experiments and the investigations of theories to find the transition signal of the quark-gluon plasma phase. As a thermodynamic and statistical model, the multi-source thermal model is developed. This model has a clear picture, simple calculation and in association with the experimental measurements. In this thesis, the multi-source thermal model is used to analyze the distribution characteristics of final-state particles, especially the particle distribution characteristics in multi-production processes. The main contents of this work include two parts given in the following.(1) The energy spectra and fragmentation functions of jets formed in proton-proton collisions at?=200GeV are studied by using the multi-source thermal model. In the framework of the model, we use a multi-component Erlang distribution. The numbers of components and groups are obtained. The results calculated from the model are consistent with the experimental data of energy spectra of jets. By using the same method, the modeling results are in agreement with the experimental data of fragmentation function distributions of jets. This work shows that the multi-source thermal model is appropriate and correct in analyses of the energy spectra and fragmentation functions of jets formed in proton-proton collisions at the RHIC energy.(2) By using the same model, the multiplicity and pseudorapidity distributions of final-state particles produced in proton-proton (proton-antiproton) collisions at0.9,2.36, and7Te V are analyzed. According to the internal mechanism of particle collisions, we divide the final-state particles’sources into three parts:a projectile fragmentation cylinder, a center cylinder and a target fragmentation cylinder. By comparing the multi-source thermal model with the geometric model, we can obtain the parameter values. The results calculated from the model are in agreement with the experimental data. One can say that the multi-source thermal model is successful in the descriptions of multiplicity and pseudorapidity distributions of final-state particles produced in proton-proton (proton-antiproton) collisions at the LHC energies.