Phenomenological Studies In The μfrom ν Supersymmetric Standard Model

The μ from v Supersymmetric Standard Model (μv/SSM), introduces three singlet right-handed neutrino superfields to solve the μ problem of the Minimal Supersymmetric Standard Model (MSSM) and can generate three tiny Majorana neutrino masses through the seesaw mechanism. In Chapter 2 of this dissertation, we present the ingredients of the μvSSM, by introducing its superpotential, the soft breaking terms, the minimization conditions of the scalar potential and the mass matrices of particles. In particular, we strictly separate the unphysical Goldstone bosons from the scalars and derive the relevant interaction Lagrangian in this model. Then in later chapters, we begin the phenomenological studies in the μvSSM.Recently, the ATLAS and CMS Collaborations at the Large Hadron Collider have report-ed significant excess events for a new boson, which is interpreted as the neutral Higgs boson with mass around 125 GeV at 5.0 a level. The CP properties and couplings of the particle are also being studied. This implies that the Higgs mechanism to break electroweak symmetry has a solid experimental cornerstone. In Chapter 3, we firstly consider the main radiative corrections to the Higgs boson mass in the μvSSM, including two-loop leading-log effects. Then, we investigate the 125 GeV Higgs decay channels hâ†'γγ,hâ†'VV* (V=Z,W), and hâ†'ff(f=b,Ï„) in the model. In the numerical analysis, we show the light stop and stau contributions to the Higgs boson decay rates in the μvSSM, which can account for the experimental data on the Higgs boson.To detect the charged lepton flavor violating (LFV) processes is an attractive thing, because any signal of LFV in charged lepton sector would be a hint of new physics. So in Chapter 4, we study the lepton flavor violating processes, including Zâ†'li±lj(?),lj-â†'lj-γ, lj-â†'lj-lj-lj+ and muon conversion to electron in nuclei within the μvSSM. Considered the slepton flavor mixing, the branching ratio of the LFV processes in the model can be increased greatly, which can easily reach the experimental observed sensitivities.At last, in Chapter 5, applying effective Lagrangian method, we study the transition magnetic moments of Majorana neutrinos in the μvSSM. Under the constraints from neutrino oscillations, we consider the two possibilities on the neutrino mass spectrum with normal or inverted ordering. Compared with the Standard Model with three tiny massive neutrinos, the transition magnetic moments of Majorana neutrinos in the μvSSM can enhance about two order of magnitude.