New Physics And Two-loop Electroweak Corrections To The Moun Anomalous Dipole Moments And Bâ†'X_sγ

At both aspects of experiment and theory, the magnetic dipole moments (MDMs) of leptons draw great attention of physicists because of their obvious importance. The analysis of the anomalous dipole moments of lepton not only detect new physics beyond the standard model (SM), but also can be used for testing loop effect in electroweak theories. On the other hand, the main purpose of investigating B-decay, especially the rare decay modes, is to search for traces of new physics and determines its parameter space.Firstly, an introduction for the SM is reviewed, then a brief review about the status of theoretical and experimental research on the muon g-2 is presented, especially for the various contributions to aμin the theoretical prediction within the framework of the SM Additional, a brief review about B-decay is provided, also the present of the study on the theoretical prediction on the Branch ratios of B meson rare decay. B→Xs-γis given.The electroweak (EW) corrections to the MDMs and electric dipole moments (EDMs) from some two loop diagrams in which a closed heavy fermion loop is inserted into those two Higgs doublet diagrams are investigated in this thesis. Adopting on-shell scheme, the ultraviolet divergence caused by the subdiagrams is subtracted and the theoretical predictions on lepton MDMs is obtained. As the masses of virtual fermions in inner loop are much heavier than the electroweak scale, the final results satisfying the decoupling theorem explicitly is verified. As application of this thesis's analysis, the leading corrections from those two-loop diagrams to the lepton MDMs in some popular extensions of the SM are presented, such as the fourth generation, supersymmetry, universal extra dimension, and the littlest higgs with T-parity.Applying effective Lagrangian method and on-shell scheme, the EW corrections to the rare decay B→Xs-γfrom some special two loop diagrams in which a closed heavy fermion loop is attached to the virtual charged gauge bosons or Higgs is investigated. The analysis shows that the final results satisfy the decoupling theorem explicitly when the interactions among Higgs and heavy fermions do not contain the nondecoupling couplings. the relative corrections from those two loop diagrams to one loop SM theoretical prediction on the branch-ing ratio of B→Xs-γversus with the possible CP violation phases and energy scale of new physics is presented. The numerical results indicate that the relative corrections from those two loop diagrams can reach 5% if there is not contingent cancelation among different sectors of corresponding contributions.