多重散射效应对部分相干源两粒子关联函数的影响

Abstract

The normal method handling the HBT rescattering effect is classical random cascade of secondary collision in high energy heavy ion collisions program whose goal is to seek the quark-gluon plasma. Interferometry, also called Hanbury-Brown Twiss (HBT) effects, is an important tool to study the space-time feature of particle-emitting source, and is an effective method to examine the quantum chromodynamics phase transition. As the HBT interference phenomenon of two identical particles is quantum mechanical in nature, and HBT results are affected by the particle-emitting source collective expansion, excited-particle decays and rescattering of particles in the source, hence, these effects should be studied properly in quantum mechanics frame. In this thesis, based on Glaubers scattering model, we use the method of path integral to analysis the rescattering effect on two-particle correlation functions of the partially coherent sources and give the formulas of two-particle correlation functions adding a absorbing factor due to rescattering effect by studying the quantum transport of the interfering identity particle pair, which include the rescattering effect. The two-particle correlation functions of the partially coherent sources contain a phase which is sensitive to the asymmetry of the source emission function and the rescattering effect shift the phase from zero and cause asymmetry of particle emission source. We investigate the influence of rescattering in high energy heavy ion collision on two-particle correlation functions for the partially coherent sources by Monte Carlo calculations. The result shows that the rescattering effect makes the phase not equal zero, causing asymmetry of particle emission source. The rescattering effect makes particles hard to emit from the center of sources, particles tend to emit from the surface of sources and the emitting time shorten. The Gaussian-formula fit results to the simulated two-particle correlation functions indicate that rescattering effect leads to a smaller interferometry radius due a shorter emitting time.