The QCD Corrections Of The Process H??_bZ

In 2012,in European Organization for Nuclear Research's large hadron collider to detect the quality of for around 125 GeV neutral Higgs boson,will say it is a standard model of elementary particles in finally found one,it is found that marks the standard model predicted all the elementary particles were found.The Higgs boson has been one of the hot topics in physics particle research.Because of the Higgs easy to decay,it is difficult to detect in experiment,so there is still some experimental phenomena about the Higgs boson can not be detected or some results still have considerable errors,it was once suspected that the presence of the Higgs boson on the probe was a particle predicted by the standard model,so the Higgs boson decays,related couplings and so on physical phenomenon and the related theory have been the physics by focus on the important research areas.In this paper,we investigate the 125 GeV Higgs boson decay to a pseudoscalar quarkonium ?b and Z boson.We calculate the quantum chromodynamics(QCD)one-loop corrections to the branching ratio of the process both in the Standard Model and in the two Higgs double models(THDM),and some accurate results are obtained.The standard model is generally regarded by physicists as the most successful model for describing particle interactions.The first chapter introduces particle physics and the standard model,including the discovery process and basic properties of each elementary particle,the basic mechanism of the standard model and its Lagrangian.The standard model also has some defects,so a large number of new models based on the standard model appear one after another.The two Higgs double models is a minimal extension of the standard model.The two Higgs double models,which contains newly possible flavor changing neutral currents and newly possible CP-violation origin,is more than popular among researchers among many new models.The second chapter introduces the main structure and Lagrangian of the two Higgs double models.The quantum chromodynamics one-loop correction is made to the decay process h??bZ tree order results both in the Standard Model and in the two Higgs double models in the third chapter,the branching ratio of the decay process h??bZ was calculated in two models.Adding the QCD one-loop corrections,the branching ratio of the decay process h??bZ in the SM is Br(h??bZ)=(4.739+0.276-0.244)×105 The relative correction of that QCD one-loop level relative to the tree level of Br(h??bZ)is around 76%in the SM.Similarly,the relative correction in the THDM also can be around 75%.The key parameter,tan ?,can affect the relative correction in the THDM.The fourth chapter makes a brief summary of the main work of this paper.