【作者】 王丹；

【导师】 孙衍斌； 杨硕；

【作者基本信息】 辽宁师范大学 ， 粒子物理与原子核物理， 2016， 硕士

【摘要】 在粒子物理标准模型中,物质粒子被分成了三代。2012年7月在LHC对撞机上发现的125Ge V的类Higgs玻色子强烈限制了与SM中前三代性质类似的更重的新一代物质粒子的存在。然而,有很多现象,如宇宙中重子的不对称、中微子质量、暗物质等,SM都没有给出任何解释。因此,人们提出了的众多新物理模型,如额外维模型、超对称模型、复合Higgs模型以及小Higgs模型等。在这些模型中常常会出现具有非标准耦合的夸克,如:类矢量夸克,它们的左右手分量都与W玻色子耦合,它可以用来抵消顶夸克对Higgs玻色子圈图的贡献。类矢量夸克可以以单态、二重态或三重态形式出现在新物理模型中。作为下型夸克的一种,重费米子B’夸克就是目前被广为关注并研究的这样一种新物质粒子。本文在有效理论框架下,用高能实验模拟软件MADGRAPH模拟并研究了重费米子B’在大型强子对撞机上的成对产生。在LHC对撞机质心能量为14Te V时,产生了B’夸克对的事例。对此过程对应的各种子过程进行了归纳与分类,给出了它们对应的费曼图以及各子过程在LHC对撞机上的产生截面。希望本文的研究对在将来的LHC对撞机实验上进行的物理研究有所帮助和参考。更多还原

【Abstract】 In the standard model of particle physics,all the matter particles are grouped into three families.The existence of the new heavier family of matter particles is strongly constrained by the newly discovered Higgs-like boson with a mass of 125 GeV.However,there are many phenomena,such as the asymmetry of the baryon in the universe,the neutrino mass and dark matter,which the SM does not provide any interpretation.Therefore,a lot of new physics models,for example,the extra dimention model,the super symmetry model,the composite Higgs model and the little Higgs model,are constructed.In these models there are often quarks with non-standard couplings.Vector-like quarks,whose left and right chiral component are both coupled to the W boson,can be included in singlets,doublets or triplets.As a down-type quark,the heavy fermion B’ is such a new matter particle and has been attracted more and more attention.In this paper,the pair production of heavy fermion B’ is studied with the high energy experimental simulation program MADGRAPH though the effective theory framework.A sample of the events for the process is obtained with the LHC mass-of-center energy of14 TeV.The process is divided into several subprocess,their Feynman diagrams and the production cross section are analyzed in a detail.We hope the study could be helpful for the future LHC experimental analysis.更多还原