In this letter I discuss a class of extensions of the standard model that have a minimal number of possible parameters, but can in principle explain dark matter and inflation. It is pointed out that the so-called new minimal standard model contains a large number of parameters that can be put to zero, without affecting the renormalizability of the model. With the extra restrictions one might ca...

In the minimal supersymmetric standard model, the Higgs sector has two unknown parameters, usually taken to be tanβ ≡ v2/v1 and mA, the mass of its one physical pseudoscalar particle. By minimizing the minimum of the Higgs potential along a certain direction in parameter space, it is shown that mA = MZ + radiative correction, and if one further plausible assumption is made, tanβ > √ 3. If there...

The quantity RK = Γ(K → eν)/Γ(K → μν) studied by the experiment NA62 at CERN is known to probe lepton-flavour violating (LFV) parameters of the Minimal Supersymmetric Standard Model (MSSM). A non-zero parameter δ RR can open the decay channel K → eντ and enhance RK over its Standard-Model value. In the region of the parameter space probed by NA62 the contribution from a bino-stau loop diagram i...

We study the inclusive rare decay B → Xd + γ in the supergravity inspired Minimal Supersymmetric Standard Model and compute the CP-asymmetry in the decay rates. We show that there exist two phenomenologically acceptable sets of SUSY parameters: for one set the CP-asymmetry has the same (positive) sign as in the Standard Model and lies in the range (5−45)% while for the other set it is negative ...

I review a heterotic–string solution in which the observable sector effective field theory just below the string scale reduces to that of the MSSM, with the standard observable gauge group being just SU(3)C ×SU(2)L×U(1)Y and the SU(3)C ×SU(2)L×U(1)Y – charged spectrum of the observable sector consisting solely of the MSSM spectrum. Associated with this model is a set of distinct flat directions...