The One Loop Correction To Two Higgs Doublets Decay H～+�'t(?) In Model Ⅱ And Model Ⅲ

Higgs mechanism is very important to the Standard Model. The theoretical study on Higgs boson's physical properties and its decay process is significant to find Higgs bosons in experiments. The Standard Model is successful in lower energy scale, but it is a low energy approximate theory. In higher energy scale the Standard Model must be expanded. Recent years, physicists effort to explore new physics beyond the Standard Model. One of the minimal extensions of Standard Model is the so called "Two-Higgs-Doublet" model which introduce two function φ1 and φ2. In this model, according to the different coupling modes, people had developed several models, i.e., Model I, II, III, IV. Model II had been discussed several years ago. Recent years, people find parameter space will be larger in Model III which is especially significant to the CP violation. The last theoretical research prove the particle's properties and its decay mode has important change in Model III. One maybe obtain much more new physics in Model III.The analysis of present theories show mH+ > mt. So the dominant hadronic decay mode of charged Higgs boson is H+ → tb if the charged Higgs boson is heavier than the top quark which has been discussed in many literatures. In this paper, we perform the tree-level and one loop correction to Two-Higgs-Doublet decay H → tb in Model II and Model III and give diagrams of the trend of tree-level and correction decay width ratio versus tanβ. We find that with the increase of tanβ, the ratio decay width ratio of Model II and Model III also increase. That means the decay H→tb has larger decay width and then is more observable in Model III than in Model II.