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

Speaker: Kohei Kamada (Hangzhou Institute for Advanced Study, U of Chinese Academy of Sciences)
Title: B-L magnetic helicity and lepton asymmetry from axion inflation
Date (JST): Tue, Sep 30, 2025, 13:30 - 14:30
Place: Seminar Room B
Abstract: In the context of axion inflation, inflaton can couple to gauge fields through the Chern-Simons coupling.This coupling gives rise to an instability of helical U(1) gauge fields. If the B-L symmetry in the Standard Model is gauged, at the end of inflation through the chiral anomaly we have helical B-L magnetic fields and B-L asymmetry in the visible and sterile sector, while the total B-L asymmetry vanishes. It can be possible that all the asymmetry finally cancels out in the thermal history of the Universe after inflation. But we succeeded in constructing a scenario where the present baryon asymmetry can be explained through the B-L genesis in this model. In this talk, I explain the essence for this scenario to be successful.