A Study Of HVV Anomalous Coupling: From Amplitude Form To Angular Distribution

The search for anomalous coupling between Higgs and gauge bosons(HVV)will help us discover new CP-violation beyond the Standard Model.This paper will study the HVV anomalous coupling from two aspects:amplitude formalism and angular distribution of differential cross-section.The framework of this paper is as follows:The first chapter is the introduction.In this chapter,we explain the purpose and significance of studying HVV anomalous coupling.Chapter 2 is the theoretical background.In this chapter,we have reviewed Higgs in Standard Model,introduced the HVV effective coupling in the Beyond Standard Model and introduced the helicity amplitude method.Chapter 3 and chapter 4 are our main research work.In these two chapters,we study the anomalous HVV coupling from two aspects respectively:amplitude formalism and angular distribution of differential cross-section.Chapter 5,the final chapter,is summary and prospect.In this chapter,we summarize the previous research work and give the content of future research.In terms of amplitude formalism,using the helicity amplitude method,we have calculated some helicity amplitudes of Higgs decay via effective HVV vertex including anomalous coupling,for the cases of di-photon,2lepton-plus-a-photon and 4-lepton final state,respectively.In the calculation results we can see some regularity,the CP-amplitude relations.For the purpose of explain these relations,after explored the mathematical forms,we have calculated the amplitude decomposetion method,which has not only explained the CP-amplitude relations concisely,but also been used as a more convenient method of calculation.In terms of angular distribution of differential cross-section,we have analytically calculated the angular distributions of differential cross-sections of interference between SM,BSM CP-even and BSM CP-odd processes of gg?H?Z*Z*?2e2?,without detector effect.Although in a four-body phase space analytic integration cannot be done,we can reserve some integrals and then obtain some forms of angular distributions.From the results,angular distributions of interference cross-sections between CPeven(including SM and BSM CP-even)and CP-odd process with respect to? is antisymmetric,which have not only solved the CP interference cancellation problem to some extent,but also provided some guidance for experimentally probing the CP-violation in the HVV coupling.Furthermore these analytic results have provided a cross check for the corresponding Monte Carlo simulations.