APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Ayuki Kamada (University of Warsaw)
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.