重夸克偶素的电磁产生过程及其在热介质中的离解

发布时间：2018-03-12 21:45

本文选题：重夸克偶素　切入点：非弹性电磁产生　出处：《云南大学》2016年博士论文　论文类型：学位论文

【摘要】：本文讨论了重夸克偶素在极端相对论性p-p碰撞中的非弹性电磁产生过程,以及重夸克偶素在热介质中离解的热宽度机制。非弹性电磁过程是指入射质子与靶质子中的部分子经由交换虚光子发生反应的过程。本文发展了一套完整处理极端相对论性p-p碰撞中重夸克偶素的非弹性电磁产生过程的方法,这一方法的精确性和适用范围都优于传统的等效光子近似方法,并在在光子虚度Q2→0时可以给出等效光子近似的形式。为了避免重复计数的错误,我们采用了由Martin和Ryskin发展的权重因子方案来同时考虑相关与非相干过程的贡献。数值结果显示,只有当Qmax21GeV2时等效光子近似才有效,而在许多文献中使用等效光子近似时将Qmax2取到s(光子吸收过程的质心系能量)的量级甚至无穷大的做法会导致明显的误差,特别是对于非相干过程,等效光子近似的结果比精确结果大了两倍以上(如果不考虑权重因子,则大六倍以上)。因此如果需要考虑整个Q2区域上的物理,就需要采用完整处理的方法。本文所发展的方法虽然是以极端边缘碰撞(在这种情况里电磁过程属于主导过程之一)为例进行讨论的,但同样适用于对心碰撞的情况(此时电磁过程更多地属于高阶修正)。同时该方法也可用于计算其它经由非弹性电磁过程产生的粒子。重夸克偶素在热介质中的离解主要是由于其势能的虚部所贡献的热宽度。本文研究了横向胶子对重夸克偶素离解的热宽度机制的贡献。我们在硬热圈近似的框架下,通过对静态极限下的横向胶子有效传播子作Fourier变换获得了横向单胶子交换的等效势,并采用侯德富与李家荣发展的对横向胶子阻尼率重求和的方法来处理在计算中遇到的红外发散问题,获得了源自横向胶子的热宽度。结果表明,横向胶子贡献大大地降低了重夸克偶素在热介质中的离解温度。另一方面,因为硬热圈近似的前提(强作用耦合参数g小于1)与现有实验条件下产生的热介质并不是弱耦合系统的事实相矛盾,本文以纵向胶子的贡献为例分别考虑了协变规范和物理规范下的胶子热自能,给出了相应的重求和传播子与等效势。结果显示,被广泛使用的硬热圈单胶子交换势在现有实验条件下会给出一些较明显的误差,而在计算完整势能时必须面对规范相关的问题。
[Abstract]:This paper discusses the non elastic electromagnetic heavy quarkonium in relativistic P-P in the collision process, the width of heat and the mechanism of heavy quarkonium dissociation in the thermal medium. Inelastic electromagnetic process refers to the incident proton proton and target parts of the virtual photon process exchange reaction through the development in this paper. The process method of non elastic electromagnetic heavy quarkonium produced a complete treatment of extreme relativistic P-P photon collisions, equivalent accuracy and applicability of this method is better than the traditional approximate method, and in Q2, 0 photon waste can be given in the form of equivalent photon approximation. In order to avoid the repeat count the error, we use the weighting factor by Martin and Ryskin development to consider related and non coherent process. At the same time. The numerical results show that only when Qmax21GeV2 and the equivalent photon approximation is effective. Using the equivalent photon approximation in many literatures will take to s Qmax2 (center of mass energy photon absorption process) the magnitude and infinite approach leads to obvious errors, especially for the non coherent process, equivalent photon approximation results than the precise results of more than two times (if you do not consider the weight factor is more than six times larger). So if you need to consider the entire Q2 physical area, needs to use the method of complete processing. The method is based on the extreme edge of the collision (although in this case the electromagnetic process belongs to the process of leading a) were discussed, but also suitable for the collision. (the electromagnetic process more belongs to the high Jie Xiuzheng). At the same time, this method can also be used to calculate other produced by inelastic particles. The electromagnetic process of heavy quarkonium dissociation in the thermal medium is mainly caused by the potential The width of the imaginary part of the thermal contribution. This paper studies the thermal mechanism of the transverse width of the gluon heavy quarkonium dissociation contribution. In the framework of our approximate hard thermal loop under the horizontal one gluon exchange equivalent potential through the transverse gluon on the static limit of the effective propagator for Fourier transform Hou Defu and Li Jiarong, and the development of transverse gluon damping rate of weight sum method to deal with the problems encountered in the calculation of infrared divergence, the heat from the gluon transverse width. The results show that the transverse gluon contribution greatly reduces the dissociation temperature of heavy quarkonium in the thermal medium. On the other on the one hand, because of the HTL (strong coupling parameter g is less than 1) and heat medium under the present experimental conditions is not weakly coupled system reality, based on the longitudinal gluon contribution respectively considering the covariant gauge The gluon thermal and physical specifications under the self energy, given the corresponding weight sum propagator and equivalent potential. The results showed that the hard thermal loop is widely used as one gluon exchange potential will give some obvious errors in the existing experimental conditions, and in the calculation of the full potential to face norms related issues.

【学位授予单位】：云南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O572.33

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