Study Of B?K^?*?v??? And K ??v??? Decays In The A2HDM

The Standard Model of particle physics aims at the study of the elementary particle,as well as the interaction between them;it describes the strong,electromagnetic and weak interactions.So far,it is considered to be the most effective phenomenological theory,and its predictions stand the tests of high-energy experiments;however,the Standard Model still exists some puzzles,such asthat the Standard Model is an approximate theory under the low-energy,which makes people try to find New Physics models beyond it.The Large Hadron Collider at CERN is the neutrino oscillation.It is believed performing a long program to search for New Physics,and a precise measurement of rare quark flavour transitions is also a powerful tool to proble New Physics.One of the simplest ways to extend the SM is the two-Higgs-doublet model,which contains two neutral CP-even Higgs h and H,a neutral pseudoscalar A and a pair of charged Higgs.This thesis is mainly about the aligned two-Higgs-doublet model that allows both doublets to couple to the quarks and charged leptons with aligned Yukawa matrices,avoiding therefore tree-level flavor-changing neutral current and providing at the same time new sources of CP violation.These features make the aligned two-Higgs-doublet model have a rich phenomenology,both in high-energy collider experiments,as well as in low-energy flavour physics.The rare B and K decays with a neutrino pair in the final state are theoretically very clean,making these decays play an important role in testing the Standard Model and New Physics.In this thesis,we calculate these two kinds of decays both within the Standard Model and in the aligned two-Higgs-doublet model,in which we have used the combined form factors from Lattice QCD and Light-Cone-Sum-Rules,as well as the Wilson coefficient with two-loop electroweak corrections included.For all the rare charged meson decays,there is a long-distance contribution through an intermediate lepton state at the tree level,then the branching ratio can be obtained in the case of B+ ? K+v(?) by multiplying the branching ratios of B+ ??+v? and ?+?Kv?.Then,using the space for the parameters mH±,Su,Sd of the A2HDM allowed by other experiments,and combining with the latest experimental data,we discuss the limits from these two decays on the charged Higgs and Yukawa couplings.Details of the results will be presented in chapter 4.Finally,chapter 5 contains our summary and prospect.