Related papers: Electroweak vacuum lifetime in two Higgs doublet m…
We study the lifetimes of TeV-scale heavy neutral leptons (Majorana neutrinos) that appear in a model suggested by Okamura et al. [2]. We develop a convenient way to parametrize the neutrino mass texture of the model, and illustrate our…
We study a two Higgs doublet model extended by a complex singlet scalar, in which the imaginary part of the singlet serves as a dark matter (DM) candidate. In this model, degenerate masses of the three neutral Higgs bosons are crucial for…
The Higgs sector of models beyond the standard model requires special attention and study, since through them, a natural explanation can be offered to current questions such as the big differences in the values of the masses of the quarks…
We investigate the effect of fermionic electroweak multiplet dark matter models on the stability of the electroweak vacuum using two-loop renormalization group equations (RGEs) and one-loop matching conditions. Such a treatment is crucial…
We show that the Standard Model vacuum can be stabilized if all particle propagators are non-minimally coupled to gravity. This is due to a Higgs-background dependent redefinition of the Standard Model fields: in terms of canonical…
Electroweak precision data have been extensively used to constrain models containing physics beyond that of the Standard Model. When the model contains Higgs scalars in representations other than singlets or doublets, and hence rho not…
We consider examples of long-lived false vacua in quantum field theory that arise from so-called `universes'. These false vacua are protected by a $(d-1)$-form global symmetry, where $d$ is the dimension of spacetime. The lifetimes of the…
We consider the application of the multiple point criticality principle to the pure Standard Model, with a desert up to the Planck scale. According to this principle, Nature should choose coupling constant values such that the vacuum can…
The Standard Model Higgs potential becomes unstable at large Higgs field values where its quartic coupling becomes negative. While the tunneling lifetime of our current electroweak vacuum is comfortably longer than the age of the universe,…
We study the neutral minima of two-Higgs doublet models, showing that these potentials can have at least two such minima with different depths. We analyse the phenomenology of these minima for the several types of two-Higgs doublet…
We show that simple Two Higgs Doublet models still provide a viable explanation for the matter-antimatter asymmetry of the Universe via electroweak baryogenesis, even after taking into account the recent order-of-magnitude improvement on…
In the present paper we argue that the correction to the Higgs mass coming from the bound state of 6 top and 6 anti-top quarks, predicted early by C.D. Froggatt and ourselves, leads to the Standard Model vacuum stability and confirms the…
New field content beyond that of the Standard Model of particle physics can alter the thermal history of electroweak symmetry breaking in the early universe. In particular, the symmetry breaking may have occurred through a sequence of…
We have studied imposing the condition that the Standard Model effective Higgs potential should have two approximately degenerate vacua, such that the vacuum we live in is just barely metastable: the one in which we live has a vacuum…
The stability of the Standard Model (SM) Higgs vacuum is a long-standing issue in particle physics. The SM Higgs quartic coupling parameter is expected to become negative at high scales, potentially generating an unstable vacuum well before…
The electroweak phase transition in the Two-Higgs-Doublet Model is investigated. The Gibbs potential at finite temperature is computed with regard for the one-loop plus ring diagram contributions. The strong first-order phase transition…
We consider the Type-II seesaw model extended with another Higgs doublet, which is odd under the $Z_2$ symmetry. We look for the possibility of triggering the electroweak symmetry breaking via radiative effects. The Higgs mass parameter…
We suggest using Einstein's static universe metric for the metastable state after reheating, instead of the Friedman-Robertson-Walker spacetime. In this case strong static gravitational potential leads to the effective reduction of the…
Half-life estimates for neutrinoless double beta decay depend on particle physics models for lepton flavor violation, as well as on nuclear physics models for the structure and transitions of candidate nuclei. Different models considered in…
The existence of a second Higgs doublet in Nature could lead to a cosmological first order electroweak phase transition and explain the origin of the matter-antimatter asymmetry in the Universe. We obtain the spectrum and properties of the…