Related papers: Charge and Color Breaking conditions associated wi…
In the MSSM, we make a careful tree-level study of Charge and Color Breaking conditions in the plane $(H_2, \tilde{u}_L, \tilde{u}_R)$, focusing on the top quark scalar case. A simple and fast procedure to compute the VEVs of the dangerous…
Testing the stability of the electroweak vacuum in any extension of the Standard Model Higgs sector is of great importance to verify the consistency of the theory. Multi-scalar extensions as the Minimal Supersymmetric Standard Model…
The presence of scalar fields with color and electric charge in supersymmetric theories makes feasible the existence of dangerous charge and color breaking (CCB) minima and unbounded from below directions (UFB) in the effective potential,…
We examine some physically relevant implications of potentially dangerous charge and color breaking minima for supersymmetric models. First, we analyze the stability of the corresponding constraints with respect to variations of the initial…
We consider a model where right-handed neutrinos and sneutrinos are introduced to the minimal supersymmetric standard model. In the scalar potential of this model, there exist trilinear and quartic terms in scalar potential that are…
Exploring MSSM parameter space after the discovery of Higgs Boson with mass 125 GeV naturally demands large top-squark mixing or large trilinear coupling parameter $A_t$ in particular, so as to avoid excessively heavy squark, specially for…
We calculate limits on the trilinear soft-breaking parameter, $A_{t}$, in the Minimal Supersymmetric Standard model by requiring the absence of nonzero top squark vacuum expectation values. Assuming a low $\tan\beta$, which implies a large…
Although the possible existence of dangerous charge and color breaking (CCB) directions in the MSSM has been known since the early 80's, only particular directions in the field-space have been considered, thus obtaining necessary but not…
Charge and color breaking minima in SUSY theories might make the standard vacuum unstable. In this talk a brief review of this issue is performed. When a complete analysis of all the potentially dangerous directions in the field space of…
The nontrivial boundary conditions (BC's) for the Topcolor breaking are investigated in the context of the TeV-scale extra dimension scenario. In the gauge symmetry breaking mechanism via the BC's we do not need to incorporate a dynamical…
Charge symmetry breaking (CSB) in the strong interaction occurs because of the difference between the masses of the up and down quarks. The use of effective field theories allows us to follow this influence of confined quarks in hadronic…
We examine charge/colour breaking along directions in supersymmetric field space which are F and D-flat. We catalogue the dangerous directions and include some new ones which have not previously been considered. Analytic expressions for the…
In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling $y_t$ should not exceed the critical value $y_t^{crit}$, coinciding with good precision (about 0.02%) with the…
In various unified extensions of the Minimal Supersymmetric Standard Model, the Yukawa couplings of the third generation are predicted to be of the same order. As a result, low energy measured mass ratios, require large ratios of the…
A detailed study of top-quark polarizations and $t \bar t$ charge asymmetries, induced by top-squark-pair production at the LHC and the subsequent decays $\tilde t \to t \tilde \chi_1^0$, is performed within the effective description of…
The scalar potential of the Minimal Supersymmetric Standard Model (MSSM) admits the existence of vacua with non-vanishing expectation values of electrically and color charged fields. If such minima are deep enough, the physical electroweak…
In most versions of beyond the standard model (BSM) physics, the Yukawa couplings of the quarks and charged leptons are not all to the same complex scalar doublet but to different ones. Comparison to the standard model (SM) with only one…
Non-Holomorphic MSSM (NHSSM) shows various promising features that are not easily obtained in MSSM. However, the additional Non-Holomorphic (NH) trilinear interactions that attribute to the interesting phenomenological features, also modify…
The equality assumption of the b and tau Yukawa couplings at the grand-unification scale can strongly constrain the allowed parameter space of supersymmetric models. We examine the constraints in the case that there is a discrepancy > 10%…
The nontrivial boundary conditions for the Topcolor breaking are investigated in the context of the TeV-scale extra dimension scenario. We present a six dimensional model where the top and bottom quarks in the bulk have the Topcolor charge…