Related papers: Troubles with the Minimal SU(5) Supergravity Model
The ansatz of vanishing A and B parameters eliminates CP violating complex phases in soft supersymmetry-breaking parameters of the minimal supersymmetric standard model, and thus provides a simple solution to the supersymmetry CP problem.…
We consider the effects of neutralino-stau coannihilations on the cosmological relic density of the lightest supersymmetric particle (LSP) $\chi$ in the minimal supersymmetric extension of the Standard Model (MSSM), particularly in the…
We have explored the electroweak phase transition in minimal supergravity models by extending previous analysis of the one-loop Higgs potential to include finite temperature effects. Minimal supergravity is characterized by two higgs…
We consider no-scale supergravity inspired scenarios, emphasizing the possible dynamical determination of the soft supersymmetry-breaking parameters as triggered by the radiative corrections that lift an essentially flat tree-level…
Using effective field theory approach, we study the constraints from electroweak data on the SU(5)/SO(5), SU(6)/SP(6), SU(3)xU(1) little Higgs models and their variations. We construct an effective theory valid above the electroweak…
We investigate SU(5) and SO(10) GUTs with vanishing scalar masses and trilinear scalar couplings at a scale higher than the unification scale. The parameter space of the models, further constrained by b-\tau Yukawa coupling unification,…
The radiatively induced neutrino mass matrix is investigated on the basis of an SU(5) SUSY model. In order to evade the proton decay, an ansatz based on a discrete symmetry $Z_2$ is assumed: although, at the unification scale, we have two…
It is well known that the minimal renormalizable $SU(5)$ grand unified theory is ruled out: it predicts same masses of down quarks and charged leptons, the gauge couplings do not unify and neutrinos are massless. We show here that all this…
We investigate unification constraints in the simplest renormalizable non-supersymmetric SU(5) framework. We show that in the scenario where the Higgs sector is composed of the 5, 24, and 45 dimensional representations the proton could be…
Within the framework of a renormalizable $SU(5)_{L} \times U(1)_{Y}$ electro-weak gauge model with no exotic electric charges, we obtain all the neutral weak charge operators and their quantization, once the diagonalization of the neutral…
We study the radiative electroweak symmetry breaking and the relic abundance of neutralino dark matter in the supersymmetric type I seesaw model. In this model, there exist threshold corrections to Higgs bilinear terms coming from heavy…
It is analyzed the branching ratio $B(b\rightarrow s\gamma)$ in the context of minimal $N=1$ supergravity with radiatively broken electroweak symmetry group. There is a strong dependence on supersymetric parameters, but constraints on the…
We implement shifted hybrid inflation in the framework of supersymmetric $SU(5) \times U(1)_{\chi}$ GUT model which provides a natural solution to the monopole problem appearing in the spontaneous symmetry breaking of $SU(5)$. The…
We explore the phenomenology of the minimal supersymmetric flipped SU(5) GUT model (CFSU(5)), whose soft supersymmetry-breaking (SSB) mass parameters are constrained to be universal at some input scale, $M_{in}$, above the GUT scale,…
We systematically study proton decay in the minimal supersymmetric SU(5) grand unified theory. We find that although the available parameter space of soft masses and mixings is quite constrained, the theory is still in accord with…
We study models in which supersymmetry breaking appears at an intermediate scale, M_in, below the GUT scale. That is, that the soft supersymmetry-breaking parameters of the MSSM are universal at M_in. We demand that the lightest neutralino…
We study the extent to which the cosmological fine-tuning problem - why the relic density of neutralino cold dark matter particles $\chi$ is similar to that of baryons - is related to the fine-tuning aspect of the gauge hierarchy problem -…
We consider several low energy consequences arising from a class of supersymmetric models based on the gauge groups $SU(2)_L\times SU(2)_R \times U(1)_{B-L}$ and $SU(4)_C\times SU(2)_L \times SU(2)_R$ in which the gauge hierarchy and $\mu$…
SUSY/SUGRA models with naturalness defined via small $\mu$ are constrained due to experiment on the relic density and the experimental limits on the WIMP-proton cross-section and WIMP annihilation cross-section from indirect detection…
The introduction of electroweak multiplets that transform under any representation of the standard $SU(2)_L$ gauge group suggests the existence of electrically neutral stable particles capable of serving as cold dark matter in the…