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Cosmological Constraints on Gravitino LSP Scenario with Sneutrino NLSP

Toru Kanzaki·Masahiro Kawasaki·Kazunori Kohri·Takeo Moroi
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Abstract

We study the scenario where a sneutrino is the next lightest supersymmetric particle (NLSP) and decays into a gravitino and standard model particles. The daughter particles such as neutrinos and quarks cause electro- and hadronic showers and affect big-bang nucleosynthesis. It is found that despite a small branching ratio, four-body processes including quarks in the final state give the most stringent constraint on the sneutrino abundance for gravitino mass of 1 $-$ 100 GeV. Pion production by high energy neutrinos is important when the sneutrinos decay at $\sim$ 1 sec. We also discuss the thermal leptogenesis in the sneutrino NLSP scenario.

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Toru Kanzaki, Masahiro Kawasaki, Kazunori Kohri, Takeo Moroi. 2006-09-25. Cosmological Constraints on Gravitino LSP Scenario with Sneutrino NLSP. https://doi.org/10.1103/physrevd.75.025011

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