Statistical Physical Properties Of Relativistic Heavy-ion Collisions In The Resonance Substances

The high energy heavy-ion collisions open a new field in nuclear physics. The purpose of studying relativistic heavy-ion collision is to learn the properties of strong interaction for the nuclear matter at extreme condition (high temperature and high density) and to look for the possible existence of the Quark-Gluon-Plasma. From the afforded experiment data of AGS, SPS and RHIC, some macroscopic quantities by using statistical theory have already been obtained for the three energy regions. The characters in the three energy regions have also been studied. The temperature, particle density and energy density increase as the reaction energy increases. The temperature can reach 170~180MeV in RHIC region. Generally, the QGP temperature defined by QCD is 160~200MeV. So it indicates that the temperature calculated by statistical theory for hadron system at RHIC energy region has been close to QGP temperature. The statistical theory plays an important role in looking for the condition of forming QGP and how far to QGP formation.The statistical theory and the grand canonical ensemble are used, in it the matter and energy can be exchanged. The paper is divided into four parts. First is the introduction to high energy heavy-ion collisions and the theory and model used. Secondly, the particle density, energy density, net baryon density and net strangeness density are calculated, and the relation between them and chemical potential is discussed. The following two parts are the calculation for quantities in RHIC energy region. The parameters' values are calculated by least-square method from RHIC experiment data. Then in part four, the quantities such as particle density, energy density at RHIC energy are calculated with these parameters' values.In the second part, the calculations show that baryon chemical potential HB and strangeness chemical potential //sare monotonous function of net baryon density. The chemical potential of baryon is larger than that of strangeness, and they all go to zero at low side of values. The total particle density and energy density are calculated, and the linear relation is rough showed between them and net baryon density. The ratio of the total particle density to normal nuclear density (0.16fm~3) is estimated to be 5~8 in RHIC energy region and 3~6 in SPS energy region.In addition, an important result is obtained that under AGS energy, the particle system is mainly made up of baryons, while it is mainly made up of mesons beyond RHIC energy. Between them in SPS energy region, particle system is made up of both baryons and mesons. Among them the strange particles such as K meson and A,S "" are the important components.The last two parts are the calculations for quantities in RHIC energy. Through calculations, the temperature is obtained to be 161MeV in central rapidity region, and baryon chemical potential to be 22MeV, strangeness chemical potential to be 4.8MeV. The net baryon density is obtained to be 0.0083fm~3. The temperature is close to the temperature in SPS energy region, but quite faraway from the former predicted temperature in RHIC energy region, so it needs further study. Besides, in central rapidity region in RHIC, the particle density is calculated to be 0.42/ fin3 (3 times of normal nuclear density) and energy density to be OAlGeVI fm3.