MeV-GeV gamma-ray telescopes probing axino LSP/gravitino NLSP as dark matter in the $\mu \nu$SSM

GERMAN A. GOMEZ-VARGAS, DANIEL E. LOPEZ -FOGLIANI, CARLOS MUNOZ, ANDRES D. PEREZ

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2020 vol. 2020 p. 1 - 28

1475-7516

Axino and gravitino are promising candidates to solve the dark matter(DM) problem in the framework of supersymmetry. In this work, weassume that the axino is the lightest supersymmetric particle (LSP),and therefore contributes to DM. In the case of R-parity violatingmodels, the axino can decay into a neutrino-photon pair with alifetime much longer than the age of the Universe, yielding apotentially detectable signal. Interestingly, a gravitino next-to-LSP(NLSP) can live enough as to contribute to the relic density. Westudy both scenarios, only axino LSP as DM, and axino LSP withgravitino NLSP as DM. We carry out the analysis in the context of theμνSSM, which solves the μproblem and reproduces neutrino data, only adding couplings involvingright-handed neutrinos. In particular, we perform a complete analysisof the relevant parameter space of the model considering constraintsfrom neutrino physics, cosmological observations, and γ-raydetection. We find that the axino or the gravitino can produce asignal detectable by future MeV-GeV γ-raytelescopes. In addition, in a parameter region where we get awell-tempered mixture of both particles, a double-line signal arisesas a smoking gun. p { margin-bottom: 0.1in; line-height: 120% }a:link { so-language: zxx }