Ref HAL: in2p3-00121100_v1
Ref Arxiv: hep-ph/0504021
DOI: 10.1016/j.physletb.2006.12.025
Ref. & Cit.: NASA ADS
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25 citations
Résumé:

It is shown that gravitinos with mass m_{3/2} ~ 0.1-1 MeV may provide suitable cold dark matter candidates in scenarios of gauge mediated supersymmetry breaking (GMSB) under SO(10) grand unification coupled to supergravity, which accommodate a messenger sector of mass scale M_X ~ 10^6 GeV. This is due to the combined effects of renormalizable loop-suppressed operators and generic non-renormalizable ones governing the dilution of a pre-existing equilibrium gravitino abundance via messenger decay. The above range of gravitino and messenger masses can be accommodated in indirect GMSB scenarios. The gravitino abundance does not depend on the post-inflationary reheat temperature and it is shown that leptogenesis can generate successfully the baryon asymmetry.

Commentaires: 8 pages - version to appear in Phys.Lett.B ; discussion of one loop annihilation cross-section modified, conclusions unchanged

Ref HAL: in2p3-00025952_v1
Ref Arxiv: hep-ph/0506129
DOI: 10.1103/PhysRevD.73.043514
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
40 citations
Résumé:

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.

Commentaires: 20 pages, double column revtex format, 5 figures

DOI: 10.1007/10857580_45
Résumé:

Considering a NFW halo of M 31 made of neutralinos, predictions for the \x{03B3} fluxes are computed for different sets of SUSY parameters using the DarkSuspect MC simulation [1] [2]. Then they are compared with the efficiency of CELESTE Cerenkov telescope [3] which has a threshold energy of 30 GeV.

Commentaires: Astronomy, Cosmology and Fundamental Physics:

Ref HAL: in2p3-00087404_v1
Ref Arxiv: astro-ph/0212560
Ref. & Cit.: NASA ADS
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Résumé:

It is widely believed that dark matter exists within galaxies and clusters of galaxies. Under the assumption that this dark matter is composed of the lightest, stable supersymmetric particle, assumed to be the neutralino, the feasibility of its indirect detection via observations of a diffuse gamma-ray signal due to neutralino annihilation within M31 is examined.

Commentaires: Latex, 5 pages, 3 figures, to appear in the proceedings of the French Astrophysical Society, 2002 - GAM

DOI: 10.1007/10857580_49
1 citation
Résumé:

The distant globular cluster Palomar 13 has been found to have a very high mass-to-light ratio. Its profile can be well fitted either by using a King model with a tail, or by a NFW model [1]. This cluster may be the first case of the many clumps predicted by CDM simulations that would not be disrupted by the galactic halo potential. We assume that Pal 13 is made of neutralinos and we run the DarkSuspect code for five benchmark models. This code allows to estimate the gamma-ray flux produced in annihilations of neutralinos. These fluxes may be used as targets to be reached in proposals for future ground-based high altitude Cerenkov telescopes.

Commentaires: A 2-page poster.

Ref Arxiv: astro-ph/0210184
DOI: 10.1016/j.astropartphys.2003.07.001
Ref. & Cit.: NASA ADS
17 citations
Résumé:

t is widely believed that dark matter exists within galaxies and clusters of galaxies. Under the assumption that this dark matter is composed of the lightest, stable supersymmetric particle, assumed to be the neutralino, the feasibility of its indirect detection via observations of a diffuse gamma-ray signal due to neutralino annihilations within M31 is examined. To this end, first the dark matter halo of the close spiral galaxy M31 is modeled from observations, then the resultant gamma-ray flux is estimated within supersymmetric model configurations. We conclude that under favorable conditions such as the rapid accretion of neutralinos on the central black hole in M31 and/or the presence of many clumps inside its halo with $r^{-3/2}$ inner profiles, a neutralino annihilation gamma-ray signal is marginally detectable by the ongoing collaboration CELESTE.

Ref HAL: hal-00347339_v1
Ref Arxiv: hep-ph/9912527
DOI: 10.1016/S0550-3213(00)00198-X
Ref. & Cit.: NASA ADS
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53 citations
Résumé:

We study the associated production of charged Higgs bosons with $W$ gaugebosons in high energy $e^+ e^-$ collisions at the one loop level. We presentthe analytical results and give a detailed discussion for the total crosssection predicted in the context of a general Two Higgs Doublet Model (THDM).

Commentaires: Latex, 31 pages, 6 figures, cosmetically improved and one reference added Journal: Nucl.Phys. B581 (2000) 34-60; Erratum-ibid. 2004 (2004) 400-401