Related papers: Constraining the $g'_1$ coupling in the minimal $B…
We examine the unitarity constraints in gauge and scalar sectors of non-minimal Universal Extra Dimensional model. We show that some of the tree-level two-body scattering amplitudes in gauge and scalar sectors do not respect partial wave…
We present a concise survey of the running of gauge couplings in realistic models of gauge-Higgs grand unification in a slice of AdS$_5$ space and investigate their potential unification. Besides unifying the gauge groups of the Standard…
Unification of electromagnetic, weak, and strong coupling constants is studied in the extension of standard model with additional fermions and scalars. It is remarkable that this unification in the supersymmetric extension of standard model…
Bardeen has argued that once the classically conformal invariance and its minimal violation by quantum anomalies are imposed on the SM, it can be free from the quadratic divergences and hence the gauge hierarchy problem. Under the…
We reexamine sterile neutrino dark matter in gauged $U(1)_{B-L}$ model. Improvements have been made by tracing and careful evaluation of the evolution of the number densities of sterile neutrinos $N$ and extra neutral gauge bosons $Z'$. As…
We consider the possibility of unification of the Supersymmetric Standard Model gauge groups with those of the dynamical supersymmetry breaking (DSB) sector in theories with gauge mediated supersymmetry breaking. We find constraints on the…
We consider a quark-lepton symmetry model of unification of the strong and electromagnetic interactions. The model has the gauge group $SU(4)\times U(1)_{Y}$ and the minimal Higgs structure consisting of one complex quartet of scalar…
In D-brane models, different part of the 4-dimensional gauge group might originate from D-branes wrapping different cycles in the internal space, and then the standard model gauge couplings at the compactification scale are determined by…
This Thesis is devoted to the study of the phenomenology of the Higgs sector of the minimal $B-L$ extension of the Standard Model at present and future colliders. Firstly, the motivations that call for the minimal $B-L$ extension are…
We discuss the equivalence between Type I, Type II and Heterotic N=2 superstring theories in four dimensions. We study the effective field theory of Type I models obtained by orientifold reductions of Type IIB compactifications on…
We consider the minimal U(1)$_{B-L}$ extension of the Standard Model (SM) with the classically conformal invariance, where an anomaly free U(1)$_{B-L}$ gauge symmetry is introduced along with three generations of right-handed neutrinos and…
A method is proposed for a self-consistent evaluation of the coupling constant in the Gross-Pitaevskii equation without involving a pseudopotential replacement. A renormalization of the coupling constant occurs due to medium effects and the…
We reconsider the problem of bounding higher derivative couplings in consistent weakly coupled gravitational theories, starting from general assumptions about analyticity and Regge growth of the S-matrix. Higher derivative couplings are…
We examine trilinear gauge boson couplings (TGCs) in the context of the $SU(3)_W\otimes U(1)'$ gauge-Higgs unification scenario. The TGCs play important roles in the probes of the physics beyond the standard model, since they are highly…
$U(1)^\prime$ extensions of the standard model with generation-dependent couplings to quarks and leptons are investigated as an explanation of anomalies in rare $B$-decays, with an emphasis on stability and predictivity up to the Planck…
In this paper we investigate a natural extension of the Standard Model that involves varying coupling constants. This is a general expectation in any fundamental theory such as string theory, and there are good reasons for why new physics…
In this paper we continue the study of the truncated conformal space approach to perturbed boundary conformal field theories. This approach to perturbation theory suffers from a renormalisation of the coupling constant and a multiplicative…
The relevant phenomenology and the best search schemes of a subelectroweak-scale gauge boson can be vastly different depending on its coupling. For instance, the rare decay into a light gauge boson and the high precision parity test can be…
We investigate perturbative unitarity constraints in a model for a singlet scalar dark matter candidate. Considering elastic two particle scattering processes of the Higgs particle and the dark matter candidate, a real Klein-Gordon scalar…
The fact that neutrinos are massive indicates that the Standard Model (SM) requires extension. We propose a low energy (<TeV) B-L extension of the SM, which is based on the gauge group SU(3)_C x SU(2)_L x U(1)_Y x U(1)_{B-L}. We show that…