The degenerate gravitino scenario
- Departament de Física Teòrica, Universitat de València, E-46100, Burjassot (Spain)
- Department of Physics, Pusan National University, Busan 609-735 (Korea, Republic of)
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{sup −2} GeV. While for stau NLSP, temperatures of T{sub RH} ≅ 4 × 10{sup 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.
- OSTI ID:
- 22285021
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 04; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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