相关论文: Are supersymmetric models with large tan(beta) nat…
We study the isospin asymmetry as an observable in exclusive B -> K* gamma decay that can be used to study the effects of physics beyond the Standard Model. We present predictions for isospin asymmetry in Supersymmetric extension of the…
Spacetime supersymmetry is widely believed to play an important role in most fundamental theories of physics, and is usually invoked in order to address problems of naturalness. In this paper, we examine the question of whether…
We study the inclusive semileptonic rare decay $b \to s l^+ l^-$ in minimal supergravity model (mSUGRA). If tan$\beta$ is large, down-type quark mass matrices and their Yukawa couplings cannot be diagonalized at the same basis. This induces…
We analyse the mass spectrum of the Constrained Minimal Supersymmetric Standard Model at the low tan beta fixed point. We find that the model only satisfies experimental and dark matter bounds in regions where the vacuum is meta-stable --…
We discuss a supersymmetric extension of the standard model with an extra U(1) gauge symmetry. In this model, the proton stability is guaranteed by the gauge symmetry without invoking R parity. The gauge symmetry breakdown automatically…
We identify a class of supersymmetric SU(4)_c x SU(2)_L x SU(2)_R models in which imposing essentially perfect t-b-tau Yukawa coupling unification at M_GUT yields a mass close to 122-126 GeV for the lightest CP-even (SM-like) Higgs boson.…
The experiments at the Large Hadron Collider (LHC) have pushed the limits on masses of supersymmetric particles beyond the $\sim$TeV scale. This compromises naturalness of the simplest supersymmetric extension of the Standard Model, the…
We analyze the implications of the light gluino scenario for the unification of gauge and Yukawa couplings within the minimal supersymmetric standard model. Within this scheme all fermionic supersymmetric particles are naturally light,…
The LEP2 experiments pose a serious naturalness problem for supersymmetric models. The problem is stronger in gauge mediation than in supergravity models. Particular scenarios, like electroweak baryogenesis or gauge mediation with light…
The Yukawa corrections of order ${\cal O}(\alpha_{ew}m_{t(b)}^2/m_W^2)$, ${\cal O}(\alpha_{ew}m_{t(b)}^3/m_W^3)$ and ${\cal O}(\alpha_{ew}m_{t(b)}^4/m_W^4)$ to the width of sbottom decay into lighter stop plus charged Higgs boson are…
The Higgs quartic coupling has now been indirectly measured at the electroweak scale. Assuming no new low-scale physics, its running is known and, together with gauge and Yukawa couplings, it is a crucial new piece of information…
In SUGRA inspired supersymmetric models with universal boundary conditions for the soft masses, the scalar cross section $\sigma_{scalar}$ for the elastic neutralino--nucleon scattering is in general several orders of magnitude below the…
We examine supergravity models with grand unification at M_G possessing R parity invariance. Current data has begun to significantly constrain the parameter space. Thus for mSUGRA, accelerator data places a lower bound on m_{1/2} of m_{1/2}…
Here I briefly discuss why supersymmetry is considered a leading candidate of physics beyond the standard model. I also highlight the salient features of different supersymmetry breaking models. A few other symmetries, broken or intact,…
Theories which include neutrinos in large extra dimensions can be constrained by nuclear beta decay experiments. We examine universality of beta decay strengths of Fermi transitions. From this we find that the extra dimensional Yukawa…
We examine whether parameters related to the Higgs sector of the minimal supersymmetric standard model can be determined by detailed study of the production cross section and decay branching ratios of the Higgs boson. Assuming that only the…
The effective bottom Yukawa couplings are analyzed for the minimal supersymmetric extension of the Standard Model at two-loop accuracy within SUSY-QCD. They include the resummation of the dominant corrections for large values of tg(beta).…
It is a well-known fact that the minimal renormalizable supersymmetric SU(5) model is ruled out assuming superpartner masses of the order of a few TeV. Giving up this constraint and assuming only SU(5) boundary conditions for the soft…
Large corrections to the quark mass matrices at the supersymmetric threshold allow the theory to have identical Yukawa matrices in the superpotential. We demonstrate that Up-Down unification can take place in a moderate quark-squark…
We augment the Minimal Supersymmetric Standard Model with a gauged family-dependent $U(1)$ to reproduce Yukawa textures compatible with experiment. In the simplest model with one extra chiral electroweak singlet field, acceptable textures…