arXiv subjects

Genevieve Belanger

Publications and source records attributed to Genevieve Belanger.

23 records · Page 2Linked to original sources

arXiv2011

Revisiting light neutralino scenarios in the MSSM

We revisit the case of a light neutralino LSP in the framework of the MSSM. We consider a model with eleven free parameters. We show that all scenarios where the annihilation of light neutralinos rely mainly on the exchange of a light pseudoscalar are excluded by direct detection searches and by Fermi measurements of the gamma-flux from dwarf spheroidal galaxies. On the other hand, we find scenarios with light sleptons that satisfy all collider and astroparticle physics constraints. In this case, the lower limit on the LSP mass is 12.6 GeV. We discuss how the parameter space of the model will be further probed by new physics searches at the LHC.

hep-ph↗

arXiv2011

Astrophysical limits on light NMSSM neutralinos

It was recently shown that light LSP neutralinos could be found in the framework of the NMSSM. These candidates would escape known Particle Physics constraints even though they are relatively light. We now investigate the astrophysical limits which can be set on these particles. We show, in particular, that the Fermi observation of dwarf spheroidal galaxies enable to constrain the parameter space associated with these candidates. Combined with the XENON100 experimental limits, our results illustrate the complementarity between direct and indirect searches for dark matter. Yet, our findings also suggest that probing light neutralinos in the NMSSM scenario will be very difficult because the sensitivity of both dark matter direct and indirect detection experiments would have to be improved by at least six order of magnitude compared to present values in order to explore the entire parameter space. Finally, we show that the parameter space compatible with the CoGeNT signal (albeit disfavored by the XENON100 limit) is not excluded by gamma nor radio observations.

hep-ph↗

arXiv2010

Can neutralinos in the MSSM and NMSSM scenarios still be light?

Since the recent results of direct detection experiments at low mass, many authors have revisited the case of light (1 -10) GeV WIMPs. In particular, there have been a few attempts to explain the results from the DAMA/LIBRA, CDMS and/or CoGeNT experiments by invoking neutralinos lighter than 15 GeV. Here we show that in the MSSM, such light particles are completely ruled out by the TEVATRON limits on the mass of the pseudoscalar Higgs. On the contrary, in the NMSSM, we find that light neutralinos could still be viable candidates. In fact, in some cases, they may even have an elastic scattering cross section on nucleons in the range that is needed to explain either the DAMA/LIBRA, CoGeNT or CDMS recent results. Finally, we revisit the lowest limit on the neutralino mass in the MSSM and find that neutralinos should be heavier than ~28 GeV to evade present experimental bounds.

hep-ph↗

arXiv2010

Tools for Dark Matter in Particle and Astroparticle Physics

Despite several indirect confirmations of the existence of dark matter, the properties of a new dark matter particle are still largely unknown. Several experiments are currently searching for this particle underground in direct detection, in space and on earth in indirect detection and at the LHC. A confirmed signal could select a model for dark matter among the many extensions of the standard model. In this paper we present a short review of the public codes for computation of dark matter observables.

hep-ph↗

arXiv2007

Dirac Neutrino Dark Matter

We investigate the possibility that dark matter is made of heavy Dirac neutrinos with mass in the range [O(1) GeV- a few TeV] and with suppressed but non-zero coupling to the Standard Model Z as well as a coupling to an additional Z' gauge boson. The first part of this paper provides a model-independent analysis for the relic density and direct detection in terms of four main parameters: the mass, the couplings to the Z, to the Z' and to the Higgs. These WIMP candidates arise naturally as Kaluza-Klein states in extra-dimensional models with extended electroweak gauge group SU(2)_L* SU(2)_R * U(1). They can be stable because of Kaluza-Klein parity or of other discrete symmetries related to baryon number for instance, or even, in the low mass and low coupling limits, just because of a phase-space-suppressed decay width. An interesting aspect of warped models is that the extra Z' typically couples only to the third generation, thus avoiding the usual experimental constraints. In the second part of the paper, we illustrate the situation in details in a warped GUT model.

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