Speaker: | Ayuki Kamada (University of Warsaw) |
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Title: | Composite asymmetric dark matter: multi-messenger study |
Date (JST): | Fri, Jul 05, 2024, 13:30 - 15:00 |
Place: | Seminar Room A |
Abstract: |
Asymmetric dark matter (ADM) explains the present DM abundance by asymmetry between DM particles and anti-particles, like visible matter or standard model (SM) baryons. It is particularly interesting when the visible and dark asymmetries have a common origin, since their abundances are different only by a factor f ~5. In such a case, DM mass should be 1-10 GeV. ADM is naturally realized by a dark sector strong dynamics like SM QCD, where a composite particle, dark baryon, is DM. In this talk, we first illustrate how a composite ADM scenario works, by stressing roles of high-energy and low-energy portals. The high-energy portal, which equilibrates asymmetries in the early Universe, may lead to a smoking-gun signature such as ~1 GeV monochromatic antineutrino flux from ADM decay. At the same time, the low-energy portal, which releases an entropy from dark sector to SM sector, may lead to ~1 GeV electrons, positrons and gamma rays from the same ADM decay. In the second part of the talk, we discuss multi-messenger constraints of ADM decay signals. |