Ref Arxiv: 2012.13947
DOI: 10.1103/PhysRevD.103.115006
Ref. & Cit.: NASA ADS

Ref HAL: hal-00608687_v1
Ref Arxiv: 1105.1925
DOI: 10.1103/PhysRevD.84.095005
Ref. & Cit.: NASA ADS
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111 citations
Commentaires: 55 pages, 9 figures, no major changes, references added, a comment added to sec 3.1, typos corrected

Ref HAL: hal-00344952_v1
Ref Arxiv: 0812.0788
DOI: 10.1103/PhysRevD.80.063509
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
50 citations
Résumé:

Supersymmetric extensions of the standard model of particle physics assumingthe gravitino to be the lightest supersymmetric particle (LSP), and with thenext-to-LSP decaying to the gravitino during Big Bang nucleosynthesis, areanalyzed. Particular emphasis is laid on their potential to solve the "Li7problem", an apparent factor 2-4 overproduction of Li7 in standard Big Bangnucleosynthesis (BBN), their production of cosmologically important amounts ofLi6, as well as the resulting minimum gravitino dark matter densities in thesemodels. The study includes several improvements compared to prior studies.Heavy gravitinos in the constrained minimal supersymmetric standard model(CMMSM) are reanalyzed, whereas light gravitinos in gauge-mediatedsupersymmetry breaking scenarios (GMSB) are studied for the first time. It isconfirmed that decays of NLSP staus to heavy gravitinos, while producing allthe dark matter, may at the same time resolve the Li7 problem. For NLSP decaytimes ~ 1000 sec, such scenarios also lead to cosmologically important Li6 (andpossibly Be9) abundances. However, as such scenarios require heavy > 1 TeVstaus they are likely not testable at the LHC. It is found that decays of NLSPstaus to light gravitinos may lead to significant Li6 (and Be9) abundances,whereas NLSP neutralinos decaying into light gravitinos may solve the Li7problem. Though both scenarios are testable at the LHC they may not lead to theproduction of the bulk of the dark matter. A section of the paper outlinesparticle properties required to significantly reduce the Li7 abundance, and/orenhance the Li6 (and possibly Be9) abundances, by the decay of an arbitraryrelic particle.

Commentaires: 13 pages (revtex), 9 figures. publié, 10.1103/PhysRevD.80.063509

Ref HAL: in2p3-00252151_v1
Ref Arxiv: 0712.3151
DOI: 10.1103/PhysRevD.77.055014
Ref. & Cit.: NASA ADS
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6 citations
Résumé:

We study the complementarity between the indirect detection of dark matter with gamma-rays in H.E.S.S. and the supersymmetry searches with ATLAS at the Large Hadron Collider in the Focus Point region within the mSUGRA framework. The sensitivity of the central telescope of the H.E.S.S. II experiment with an energy threshold of ~ 20 GeV is investigated. We show that the detection of gamma-ray fluxes of O(10^-12) cm-2s-1 with H.E.S.S. II covers a substantial part of the Focus Point region which may be more difficult for LHC experiments. Despite the presence of multi-TeV scalars, we show that LHC will be sensitive to a complementary part of this region through three body NLSP leptonic decays. This interesting complementarity between H.E.S.S. II and LHC searches is further highlighted in terms of the gluino mass and the two lightest neutralino mass difference.

Commentaires: 11 pages, 6 figures, accepted for publication in Phys. Rev. D on February 7, 2008 (slight modifications: references updated and text improved)

Ref HAL: in2p3-00024566_v1
Ref Arxiv: astro-ph/0508349
DOI: 10.1103/PhysRevD.74.023518
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
9 citations
Résumé:

The detection of non-baryonic dark matter through its gamma-ray annihilation in the centre of our galaxy has been studied. The gamma fluxes according to different models have been simulated and compared to those expected to be observed with the Alpha Magnetic Spectrometer (AMS), during a long-term mission on board of the International Space Station. Under the assumption that the dark matter halo is composed of the lightest, stable supersymmetric particle, the neutralino, the results of the simulations in the framework of mSUGRA models, show that with a cuspy dark matter halo or a clumpy halo, the annihilation gamma-ray signal would be detected by AMS. More optimistic perspectives are obtained with the Anomaly Mediated Supersymmetry Breaking (AMSB) model. The latter leads also to a cosmologically important 6Li abundance. Finally, the discovery potential for the massive Kaluza-Klein dark matter candidates has been evaluated and their detection looks feasible.

Commentaires: 15 pages, 7 figures - AMS

Ref HAL: in2p3-00025722_v1
Ref Arxiv: astro-ph/0508141
DOI: 10.1088/1475-7516/2006/07/010
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
43 citations
Résumé:

Stable particle dark matter may well originate during the decay of long-lived relic particles, as recently extensively examined in the cases of the axino, gravitino, and higher-dimensional Kaluza-Klein (KK) graviton. It is shown that in much of the viable parameter space such dark matter emerges naturally warm/hot or mixed. %due to the kinetic energy imparted %on the dark matter particles during decay. In particular, decay produced gravitinos (KK-gravitons) may only be considered cold for the mass of the decaying particle in the several TeV range, unless the decaying particle and the dark matter particle are almost degenerate. Such dark matter candidates are thus subject to a host of cosmological constraints on warm and mixed dark matter, such as limits from a proper reionisation of the Universe, the Lyman-alpha forest, and the abundance of clusters of galaxies.. It is shown that constraints from an early reionsation epoch, such as indicated by recent observations, may potentially limit such warm/hot components to contribute only a very small fraction to the dark matter.

Commentaires: 6 pages, 3 figures

Ref HAL: hal-00266464_v1
Exporter : BibTex | endNote
Résumé:

A review of the activity of the European Network ``Physics at Colliders'' in the area of SUSY particle physics is presented.

Commentaires: Meeting of the European Network "Physics at Colliders", Montpellier (France) Sept-26-27 , 2004.