Related papers: $B_d - \bar{B}_d$ mass difference in Little Higgs …
Constraints on the two Higgs doublet model are presented, assuming a top mass of 174 $\pm$ 17 GeV. We concentrate primarily on the ``type II'' model, where up--type quarks receive their mass from one Higgs doublet, and down--type quarks…
The Substandard theory deals with the standard model of leptons, electro-weak gauge bosons and Higgs, excluding the chromodynamics of quarks. The theory gives a geometric and algebraic interpretation of its U(2) symmetry based on the…
Experiments are once again under way at the LHC. This time around, however, the mood in the high-energy physics community is pessimistic. There is a growing suspicion that naturalness arguments that predict new physics near the weak scale…
In these lectures we present a brief review of the Higgs boson sector in the ``Standard Model'', and its Minimal Supersymmetric Extension, with particular emphasis on the main mechanisms for Higgs production and decay at LEP2 and LHC, and…
If the "Higgs mass" is not the physical mass of a real particle but rather an effective ultraviolet cutoff then a process energy dependence of this cutoff must be admitted. Precision data from at least two energy scale experimental points…
The rare decay $B^0_s \to \mu^+\mu^-$ plays a key role for the testing of the Standard Model. It is pointed out that the sizable decay width difference $\Delta\Gamma_s$ of the $B_s$-meson system affects this channel in a subtle way. As a…
We discuss how much Higgs couplings (including the Higgs self coupling) can deviate from their Standard Model values, in different Beyond Standard Model (BSM) theories, if no other BSM states are accessible at the LHC. Then, we focus on…
We consider the K^0 - \bar K^0 and B^0 - \bar B^0 mixings in the MSSM with the two-Higgs-doublet scalar sector featuring explicit CP violation, and the Yukawa sector of type II. In the case of strong mixing between CP-odd and CP-even states…
Motivated by future collider proposals that aim to measure the Higgs properties precisely, we study the partial decay widths of the lightest Higgs boson in the minimal supersymmetric standard model with an emphasis on the parameter region…
We provide a comprehensive, up-to-date analysis of possible New Physics contributions to the mass difference $\Delta M_D$ in $D^0$-${\bar D}^0$ mixing. We consider the most general low energy effective Hamiltonian and include leading order…
The charged Higgs boson plays an essential role in distinguishing between a wide variety of standard model extensions with multiple Higgs doublets, and has been searched for in various collider experiments. This paper expands our previous…
The introduction of strongly-interacting mirror fermions with masses between the weak scale and 1 TeV could offer a viable alternative to the Higgs mechanism. The framework provided solves the hierarchy problem naturally and predicts a rich…
The hierarchy problem of the scalar sector of the standard model is reformulated, emphasizing the role of experimental facts that may suggest the existence of a new physics large mass scale, for instance indications of the instability of…
Partial Split Supersymmetry with violation of R-parity as a model for neutrino masses is explored. It is shown that at the one-loop level the model can give predictions that are in agreement with all present experimental values for the…
We put limits on the time variation of the electron mass in the early universe using observational primordial abundances of D, He4 and Li7, recent data from the Cosmic Microwave Background and the 2dFGRS power spectrum. Furthermore, we use…
The mass and the decay width of a Higgs boson in the minimal standard model are evaluated by a variational method in the limit of strong self-coupling interaction. The non-perturbative technique provides an interpolation scheme between…
This is a slightly extended version of the talk delivered at the Topical Workshop ``Non perturbative aspects of chiral gauge theories'', Accademia Nazionale dei Lincei, Roma, 9-11 March, 1992. Abstract: The Higgs mass in the minimal…
This review provides an elementary discussion of electroweak symmetry breaking in the minimal and the next-to-minimal supersymmetric models with the focus on the fine-tuning problem -- the tension between natural electroweak symmetry…
From a theoretical point of view it is not hard to imagine gaugino masses being much lighter than scalar masses. The dominant contributions to gaugino masses are then their anomaly-mediated values. Given current lower bounds on gauginos,…
We investigate the low energy phenomenology of the lighter pseudoscalar $A_1^0$ in the NMSSM. The $A_1^0$ mass can naturally be small due to a global $U(1)_R$ symmetry of the Higgs potential, which is only broken by trilinear soft terms.…