by- 12 July 2012
The search for Dark Matter which is the effective manifestation of the invisible mass of the Universe is an important transversal research axis that we want to consolidate vigorously by combining strategies like those pursued in neutrino physics. We will address the dark matter issue both by direct and indirect approaches, both through experiments and through theoretical investigations. The LAPP, LAPTh and LPSC are involved in several projects aiming at observing dark matter either directly, MIMAC (a microTPC at low CF4 pressure), located at the LSM or indirectly using the gamma-rays and antiparticles (AMS, HESS, CREAM, CTA) possibly produced by the annihilation of dark matter particles. MIMAC through the possibility of directional detection will allow an easier interpretation of a signal of Dark Matter. The combination of deep observations of gamma–rays from potential candidates of dark matter over-densities (galactic halo, clumps, dwarf galaxy) together with measurements of exotic components in the anti-matter cosmic-ray spectra (anti-p, anti-d and positrons) covers a substantial part of indirect searches of dark matter. After having contributed to the construction of the detectors, we are strongly involved in the data analysis for the on-going experiments AMS, HESS and CREAM. As we are strongly involved on the experimental side – data analysis for the on-going experiments, design for future projects – the systematic effects and possible instrumental bias will be very well controlled. For example, the LAPP has designed and built the autofocus system of HESS2 and was deeply involved in the AMS-calorimeter, whereas the LPSC was responsible for the front-end electronics of the AMS-RICH and of the whole Cherenkov counter of CREAM. In addition, the different groups of the consortium are involved in the computation of the expected fluxes, the evaluation of constraints and rates from New Physics models. They are the developers of the popular code micrOMEGAs. Very importantly, there is first class expertise in the accurate evaluation of different backgrounds that are being implemented in a powerful code (USINE) for the propagation of cosmic ray anti-protons, positrons. The Labex would substantially enhance collaborations allowing a possibly unique capability of going ahead on this most important topic by exchanging know-how and combining experimental results. This collaboration between LAPP, LAPTh and LPSC is already very active and ready to confront any discovery in the next decade.
An interaction with LHC members of ENIGMASS is crucial as constraints on New Physics models set at the colliders have an impact on the analysis for direct and indirect detection, and even the design of their detectors. Model independent searches at LHC based on topologies including missing energy and their interpretation might furnish important information on the properties of the Dark Matter candidate behind the excess in missing energy events as well as other topologies. Through the reconstruction of the relic density and confrontation with measurements at PLANCK, one can indirectly probe different issues about the history and the thermodynamics of the Universe. A signal of Dark Matter from direct or indirect detection could furnish the mass, or at least give a good idea of the mass of the Dark Matter candidate, that could help greatly in the reconstruction made at the colliders. Moreover a signal from such detectors could offer clues about the distribution of Dark Matter, if the effective annihilation cross section has been reconstructed.