TY  - JOUR
AU  - Boubekeur, L.
AU  - Choi, K. Y.
AU  - Ruiz de Austri, R.
AU  - Vives, O.
PY  - 2010
DA  - 2010//
TI  - The degenerate gravitino scenario
T2  - J. Cosmol. Astropart. Phys.
JO  - Journal of Cosmology and Astroparticle Physics
SP  - 005
EP  - 26pp
VL  - 04
IS  - 4
PB  - Iop Publishing Ltd
KW  - dark matter theory
KW  - leptogenesis
KW  - supersymmetry and cosmology
KW  - cosmology of theories beyond the SM
AB  - In this work, we explore the "degenerate gravitino" scenario where the mass difference between the gravitino and the lightest MSSM particle is much smaller than the gravitino mass itself. In this case, the energy released in the decay of the next to lightest sypersymmetric particle (NLSP) is reduced. Consequently the cosmological and astrophysical constraints on the gravitino abundance, and hence on the reheating temperature, become softer than in the usual case. On the other hand, such small mass splittings generically imply a much longer lifetime for the NLSP. We find that, in the constrained MSSM (CMSSM), for neutralino LSP or NLSP, reheating temperatures compatible with thermal leptogenesis are reached for small splittings of order 10(-2) GeV. While for stau NLSP, temperatures of T-RH similar or equal to 4 x 10(9) GeV can be obtained even for splittings of order of tens of GeVs. This "degenerate gravitino" scenario offers a possible way out to the gravitino problem for thermal leptogenesis in supersymmetric theories.
SN  - 1475-7516
UR  - http://lanl.arxiv.org/abs/1002.0340
UR  - https://doi.org/10.1088/1475-7516/2010/04/005
DO  - 10.1088/1475-7516/2010/04/005
LA  - English
N1  - ISI:000277684600028
ID  - Boubekeur_etal2010
ER  -