The minimal non - minimal standard model

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 call it the minimal (new) non minimal standard model (MNMSM). A few hidden discrete variables are present. It is argued that the inflaton should be higher-dimensional. Experimental consequences for the LHC and the ILC are discussed. With the latest developments from high energy colliders like LEP and the Tevatron the standard model (SM) has been established up to the loop level. Precision measurements leave only very little space for extensions, as these tend to spoil the agreement with experiment due to a variety of effects, one of the most important of which is the appearance of flavor-changing neutral currents. Even the most popular extension, namely the minimal supersymmetric extension of the SM has to finely tune a number of parameters. This leaves only one type of extensions that are safe, namely the singlet extensions. Experimentally right handed neutrinos appear to exist. Since these are singlets a natural extension of the SM is the existence of singlet scalars too [1-9]. These will only have a very limited effect on radiative corrections, since they appear only in two-loop calculations [10,11]. The effects of singlets appear in two forms, one is the mixing with the SM Higgs, the other is the possibility of invisible decay. In contrast to charged fields these effects can be separated. It is actually possible to have a Higgs model that has only Higgs-mixing. If one starts with an interaction of the form HΦ † Φ, where H is the new singlet Higgs field and Φ the SM Higgs field, no interaction of the form H 3 or H 4 is generated with an infinite coefficient [1].