Related papers: A Solution to the Hierarchy Problem with Non-Linea…
The effective potential of the Higgs scalar field in the Standard Model may have a second degenerate minimum at an ultrahigh vacuum expectation value. This second minimum then determines, by radiative corrections, the values of the…
Today, both particle physics and cosmology are described by few parameter Standard Models, i.e. it is possible to deduce consequence of particle physics in cosmology and vice verse. The former is examined in this lecture, in light of the…
A solution of the Randall-Sundrum model for a simplified case (one wall) is obtained. It is given by the $1/k^2$-expansion (thin wall expansion) where $1/k$ is the {\it thickness} of the domain wall. The vacuum setting is done by the 5D…
We consider the possibility of describing the Higgs effect in unified theories without the Higgs potential in the presence of the Einstein gravity with the conformal gravity-scalar coupling under the assumption of homogeneous matter…
We construct a minimal viable extension of the standard model (SM) with classical scale symmetry. Its scalar sector contains a complex singlet in addition to the SM Higgs doublet. The scale-invariant and CP-symmetric Higgs potential…
I present a concise review of the major issues and challenges in particle physics at the start of the LHC era. After a brief overview of the Standard Model and of QCD, I will focus on the electroweak symmetry breaking problem which plays a…
We show that the addition of real scalars (gauge singlets) to the Standard Model can both ameliorate the little hierarchy problem and provide realistic Dark Matter candidates. To this end, the coupling of the new scalars to the standard…
The current experimental lower bound on the Higgs mass significantly restricts the allowed parameter space in most realistic supersymmetric models, with the consequence that these models exhibit significant fine-tuning. We propose a…
The measurement of the Higgs mass at the LHC has confirmed that the Standard Model electroweak vacuum is a shallow local minimum and is not absolutely stable. In addition to a probable unacceptably fast tunneling to the deep true minimum,…
These lectures provide a concise introduction to the so-called "Beyond the Standard Model"' physics, with particular emphasis on the problem of the microscopic origin of the Higgs mass term and of the Electro-Weak symmetry breaking scale in…
We propose a mechanism to solve the Higgs naturalness problem through a cosmological selection process. The discharging of excited field configurations through membrane nucleation leads to discrete jumps of the cosmological constant and the…
Lattice work, exploring the Higgs mass triviality bound, seems to indicate that a strongly interacting scalar sector in the minimal standard model cannot exist while low energy QCD phenomenology seems to indicate that it could. We attack…
The relaxion mechanism provides a potentially elegant solution to the hierarchy problem without resorting to anthropic or other fine-tuning arguments. This mechanism introduces an axion-like field, dubbed the relaxion, whose expectation…
The Standard Model correctly describes all interactions at (and below) the electroweak scale. However it does not explain the peculiar pattern of quark, lepton and neutrino masses. Also charge quantization is not understood. These are well…
Instead of solving the fine-tuning problems by some automatic method or by cancelling the quadratic divergencies in the hierarchy problem by a symmetry (such as SUSY), we rather propose to look for a unification of the different fine-tuning…
The predictions for the Higgs mass in extensions of the Minimal Supersymmetric Standard Model are discussed. We propose a simple theory where the Higgs mass is modified at tree-level and one can achieve a mass around 125 GeV without…
We investigate the fine-tuning problem in the Standard Model and show that Higgs boson and top quark masses consistent with current experimental bounds cannot be obtained unless one extends the particle spectrum. A minimal extension which…
In this paper we have considered the possibility that the Standard Model, and its minimal extension with the addition of singlets, merges with a high-scale supersymmetric theory at a scale satisfying the Veltman condition and therefore with…
We examine the use of modified Higgs sectors to address the little hierarchy problem of supersymmetry. Such models reduce weak-scale fine-tuning by allowing lighter stops, but they retain some fine-tuning independent of the Higgs. The…
It has been suggested that electroweak symmetry breaking in the Standard Model may be natural if the Standard Model merges into a conformal field theory (CFT) at short distances. In such a scenario the Higgs mass would be protected from…