Decaying Dark Matter in the light of future MeV-GeV gamma-ray telescopes for Axino-Gravitino scenarios

ANDRES DANIEL PEREZ

Trieste

Otro; Summer School on Cosmology - Presentación de Poster; 2018

Abdus Salam International Centre for Theoretical Physics (ICTP)

Axino and gravitino particles are among the most promising candidates from supersymmetry (SUSY) frameworks to solve the dark matter identity problem. Both of them can easily evade the stringent direct detection limits and provoke fundamental changes in the cosmology of the Universe. Whether either, axino or gravitino, is the lightest supersymmetric particle (LSP) and the other is the next-to-LSP (NLSP) an exciting interplay arise. Moreover, distinct cosmological scenarios befall depending on the era in which the NLSP decays to the LSP in a so-called decaying dark matter model (DDM). There are stringent constraints if the decay takes place between recombination and present era, but some studies claim that DDM models can relax recent cosmological tensions.Furthermore, the breaking of R-parity in SUSY models implies that both, gravitino and axino particles can decay into a neutrino-photon pair, yielding a potentially detectable signal. In this work, we perform a complete analysis of the parameter space for SUSY models considering constraints from cosmological observations, $\gamma$-ray analises, and neutrino physics. In particular, we pay careful attention to the $\mu$ from $\nu$ supersymmetric model ($\mu\nu$SSM), which solves the $\mu$ problem of SUSY frameworks and reproduces neutrino observed data, only using couplings with right-handed neutrinos $\nu$'s. We find that either, the gravitino or the axino might produce a signal detectable by future MeV-GeV $\gamma$-ray telescopes, and in a particular parameter region where we get a well-tempered mixture of both candidates, a double line `smoking gun' signal arise.