by- 25 February 2013
Topics : Dark matter, cosmic rays and LHC
Proponents : Pierre Salati
Address : LAPTH - 9 chemin de Bellevue - BP 110 - 74941 Annecy-le-Vieux cedex
Phone : +33 4 50 09 16 90
Contact Email : email@example.com
The astronomical dark matter is an essential component of the universe. Discovered in 1933 by Zwicky inside the Coma cluster of galaxies, its presence from sub-galactic to cosmological scales has been since then established and confirmed by the most recent observations. The astronomical dark matter, whose nature is still unresolved, is not made of ordinary atoms and nuclei. One of the best motivated candidates is a weakly interacting and massive species – dubbed wimp – whose existence is predicted in many extensions of the standard model of particle physics.
The wimps concealed inside the halo of the Milky Way are expected to continuously annihilate and produce cosmic radiations on top of the already well-known astrophysical backgrounds. An indirect signature of the dark matter candidates is the presence of spectral distortions in gamma rays and in antimatter cosmic ray fluxes, which several experiments are already measuring with unprecedented accuracy – like Fermi/LAT, the HESS II telescope or the AMS02 spectrometer recently docked onto the international space station.
The student will get familiar with the astronomical dark matter problem and with the various wimp observational signatures. The beginning of the thesis – which consists in a training period – will be essentially devoted to the indirect signatures of wimps. The propagation of cosmic rays inside the Galaxy will be modeled. The energy spectrum of antiprotons and positrons will be estimated and compared to observations. These antimatter particles are excellent probes of exotic dark matter. Time permitting, the production of cosmic antideuterons will also be investigated. Observation of these antimatter nuclei should be within reach of AMS02 and the forthcoming GAPS detector. Antideuterons are also a sensitive probe of the presence of dark matter particles inside the Milky Way halo. During the thesis which is intended to follow the training course, the PhD student will investigate the direct and indirect signatures of wimps. She/he will analysis the contraints set by the ongoing observations – Fermi, HESS II, AMS 02, etc… – on supersymmetric or Kaluza-Klein dark matter candidates. Results from the LHC will be crucially taken into account.
The cosmic ray project could imply a collaboration with our colleagues from LAPTh who are involved in the MicroMEGAS public package. We also anticipate discussions and collaborations with our colleagues from AMS-02 at LAPP in Annecy and LPSC in Grenoble.
The antideuteron project will lead us to discuss with Charles Hailey from Columbia University and his colleagues of the GAPS collaboration.
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