Back-To-Back Correlations For Massive Bosons In High Energy Heavy Ion Collisions

The intense interferometry developed in the 1950's can provid the imformation of properties of geometric dimensions. Based on the theory of HBT correlations, Back-to-Back correlations can give us the thermodynamic properties of source such as temperature. So it is very important for high energy physicists to research the Back-to-Back correlations.So far, the research for Back-to-Back correlations is still in the stage of beginning, especially in China, there is almost no work in this field. For this reason, this thesis have summarized the history of Back-to-Back correlations. Then the thesis make a comprehensive comparison between Back-to-Back correlations and HBT correlations and get the result that the Back-to-Back correlations is based on the theory of HBT correlations. In the other hand, the function of Back-to-Back correlations can modify the fuction of HBT correlations so that the radius of source which is gained by the fuction of HBT become more precise.As is known to all, Bogoliubov transformation which is related to the squeezed effect can suppress the interaction between particle and medium into quasi-particle. Compared to the free particle, the mass-shift effect will be observed for the quasi-particle. In fact, the mass-shifted effect is the direct reason of leading to Back-to-Back correlations while the more profound reason is due to the law of momentum conservation.Normally, the effect of Back-to-Back correlations is apparent only for the massive bosons. The effect of Back-to-Back correlations is simulated by the static gaussian model successfully through the simulation to the Back-to-Back correlations for the massive bosons. Although the model used in this thesis is very simple, this result can provide the research experience for others who want to research the Back-to-Back correlations by using other models. According to the result of simulation, the curves of the Back-to-Back correlations for particle and anti-partile pairs are gained under the different temperature after fixing a value of mass-shifted. These curves also can be used to find out the temperature of source. Due to ignoring the effect of finite time suppression and the distribution of other kinds of particle, the increasing function of the Back-to-Back correlations with momentum is gained for ? mesons in this thesis.