Narrow Results

The scalar mass is determined in the simplest cut-off regularized Yukawa-model in the whole range of stability of the scalar potential. Two versions of the Functional Renormalisation Group (FRG) equations are solved in the Local Potential Approximation (LPA), where also the possible existence of a composite fermionic background is taken into account. The close agreement of the results with previous studies taking into account exclusively the effect of the scalar condensate, supports a rather small systematic truncation error of FRG due to the omission of higher dimensional operators.

We introduce the deformed boson condensate and argue that its properties are consistent with the properties of the dark matter (DM). For every candidate of DM, the mass bounds evaluation is important. Therefore, the lower and upper bounds of mass are evaluated using the phase space density and observational data for q deformed Bose–Einstein condensate (q-BEC) model. We show that the upper bound of q-BEC and ordinary BEC model is the same, while for small values of q, the lower bound tends to zero which is in favor of the light DM particles.

We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations, SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations, MSSM(3,4). Our analysis utilizes the SM(3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM(3,4), while the lower bounds in the SM(3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.

The scalar mass is determined in the simplest cut-off regularized Yukawa-model in the whole range of stability of the scalar potential. Two versions of the Functional Renormalisation Group (FRG) equations are solved in the Local Potential Approximation (LPA), where also the possible existence of a composite fermionic background is taken into account. The close agreement of the results with previous studies taking into account exclusively the effect of the scalar condensate, supports a rather small systematic truncation error of FRG due to the omission of higher dimensional operators.