Orateur
M.
Yifan CHen
(LPTHE)
Description
Motivated by the absence of signals of new physics in both searches for new particles at LHC and for a Weakly Interacting Massive Particle (WIMP) dark matter candidate, we consider a scenario where supersymmetry is broken at a scale above the reheating temperature. The low energy particle content consists then only in Standard Model states and a gravitino. We investigate the possibility that the latter provides the main component of dark matter through a freeze in mechanism from annihilation of thermalized Standard Model particles. We focus on the case where its production through scattering in the thermal plasma is well approximated by the non-linear supersymmetric effective Lagrangian of the associated goldstino and identify the parameter space allowed by the cosmological constraints, allowing the possibility of large reheating temperature compatible with leptogenesis scenarios, alleviating the so called ”gravitino problem”. We considered the framework of high scale supersymmetry, where the scale of super-partners MSUSY lies above the reheating temperature whereas the gravitino mass m3/2 stays below. In this case, there still exist processes which produce thermally gravitinos through scattering of the Standard Model particles at the earliest time of reheating. This scale pattern m3/2 ≪ TRH ≪ MSUSY is common in some string models with high-scale supersymmetry breaking and opens new possibilities in model building.
Author
M.
Yifan CHen
(LPTHE)
