arXiv subjects

Gilbert Moultaka

Publications and source records attributed to Gilbert Moultaka.

23 records · Page 2Linked to original sources

arXiv2006

Gravitino dark matter in gauge mediated supersymmetry breaking

This paper investigates the parameter space of theories with gauge mediated supersymmetry breaking leading to gravitino (cold) dark matter with mass m_{3/2}= 1keV - 10MeV. We pay particular attention to the cosmological role of messenger fields. Cosmology requires that these messengers decay to the visible sector if the lightest messenger mass M_X > 30TeV. We then examine the various possible messenger number violating interactions allowed by the symmetries of the theory and by phenomenology. Late messenger decay generally results in entropy production hence in the dilution of pre-existing gravitinos. We find that in SU(5) grand unification only specific messenger-matter couplings allow to produce the required amount of gravitino dark matter particles. Gravitino dark matter with the correct abundance is however expected in larger gauge groups such as SO(10) for generic non-renormalizable messenger-matter interactions and for arbritrarily high post-inflationary reheating temperatures.

hep-ph↗

arXiv2005

SuSpect: a Fortran Code for the Supersymmetric and Higgs Particle Spectrum in the MSSM

We present the Fortran code SuSpect version 2.3, which calculates the Supersymmetric and Higgs particle spectrum in the Minimal Supersymmetric Standard Model (MSSM). The calculation can be performed in constrained models with universal boundary conditions at high scales such as the gravity (mSUGRA), anomaly (AMSB) or gauge (GMSB) mediated breaking models, but also in the non-universal MSSM case with R-parity and CP conservation. Care has been taken to treat important features such as the renormalization group evolution of parameters between low and high energy scales, the consistent implementation of radiative electroweak symmetry breaking and the calculation of the physical masses of the Higgs bosons and supersymmetric particles taking into account the dominant radiative corrections. Some checks of important theoretical and experimental features, such as the absence of non desired minima, large fine-tuning in the electroweak symmetry breaking condition, as well as agreement with precision measurements can be performed. The program is user friendly, simple to use, self-contained and can easily be linked with other codes; it is rather fast and flexible, thus allowing scans of the parameter space with several possible options and choices for model assumptions and approximations.

hep-ph↗

arXiv1997

Model-independent $\tan β$ bounds in the MSSM

We demonstrate, through the study of the one-loop effective potential in the MSSM, the existence of fully model-independent lower and upper theoretical bounds on $\tan β$. We give their general analytic form and illustrate some of their implications.

hep-ph↗

arXiv1997

Novel Electroweak Symmetry Breaking Conditions From Quantum Effects In The MSSM

We present, in the context of the Minimal Supersymmetric Standard Model, a detailed one-loop analytic study of the minimization conditions of the effective potential in the Higgs sector. Special emphasis is put on the role played by $Str M^4$ in the determination of the electroweak symmetry breaking conditions, where first and second order derivatives of the effective potential are systematically taken into account. Novel, necessary (and sufficient in the Higgs sector) model-independent constraints, are thus obtained analytically, leading to new theoretical lower and upper bounds on $\tan β$. Although fully model-independent, these bounds are found to be much more restrictive than the existing model-dependent ones! A first illustration is given in the context of a SUGRA-GUT motivated scenario.

hep-ph↗

arXiv1997

One-Loop Minimization Conditions in the Minimal Supersymmetric Standard Model

We study, in the Minimal Supersymmetric Standard Model, the electroweak symmetry breaking conditions obtained from the one-loop effective potential. Novel model-independent lower and upper bounds on $\tan β$, involving the other free parameters of the model, are inferred and determined analytically. We discuss briefly some of the related issues and give an outlook for further applications.

hep-ph↗