| DATE: |
2006-11-14 11:00 - 12:00 |
| PLACE: |
Kenkyuhonkan2F rm.220 |
| TITLE: |
Cosmological Constraints on Gravitino LSP scenario with Sneutrino NLSP |
| CONTACT: |
tsuda |
| SPEAKER: |
Toru Kanzaki (ICRR) |
| LANGUAGE: |
Japanese |
| 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 ~ 1 sec. We also discuss the thermal leptogenesis in the sneutrino NLSP scenario. |
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