The Effect Of Multiple Scattering On The Interferometry Of A Partially Coherent Source

The goal of high-energy heavy ion collisions physics is to study the properties ofthe particle-emitting sources produced in the collisions, and a major goal is to obtainthe information of the space-time structure of the source. Pion interferometry is animportant tool for studying the space-time structure. As the source undergoes an ex-pansion from the initial stage with high temperature and density to the final freeze-outstage, it is of great interest to investigate what source distribution the interferometrymeasures, and how the pion interferometry results are affected by the multiple scat-tering of the particles in the source. In this thesis ,we study the effects of the multiplescattering on pion interferometry results of a partially coherent source.We first introduce the relativistic hydrodynamics model which describes the ex-pansion of the particle-emitting source and the conditions which are needed to solvethe hydrodynamics equations and their numerical algorithm. And we give the for-mulas of two-pion Hanbury-Brown-Twiss (HBT) correlation function for a partiallycoherent evolution pion-emitting source, using path-integral formalism in quantummechanics. The multiple scattering of the particles in the source is taken into consid-eration based on Glauber scattering theory. Then we consider a spherical source ofmixed hadronic gas with a finite baryon density,which corresponding to the case of thesources produced at the AGS energies. We give the hydrodynamical solution and wegive the value of two pion correlation functions with it. After fitting the two pion cor-relation functions, we have the HBT radii and HBT coherent parameters. The resultsshow that there is no effect of the multiple scattering with Glauber theory on HBTcoherent parameter i.e. it does not affect the coherent degree of the source, though itcan affect the HBT radii.