Seminarium "High Energy, Cosmology and Astro-particle Physics (HECA)"

Axion like particle (ALP) is one of the promising candidates of dark matter (DM). It can emerge from the dark sector with global U(1) symmetry. It is often assumed that the dark sector has CP symmetry. On the other hand, however, CP is already violated in the SM by the QCD theta term and quark mixing. The dark sector with CP violation is also an interesting possibility. In this talk, we propose a new renormalizable model for ALP with CP violation in the dark sector. We discuss the properties of the predicted ALP and how the ALP can be probed at ILC. In addition, we discuss quantum effect that affects a system with multi-Higgs states. It is shown that the mixing between two Higgs bosons is highly suppressed by the quantum effect in the regime where the decay rate for the extra Higgs boson is larger than the mass difference between two Higgs bosons.

https://uw-edu-pl.zoom.us/j/9529812548