Leptonic CP asymmetry and Light flavored scalar

TL;DR

This paper explores how right-handed neutrinos decaying into flavor-dependent light scalars, possibly Nambu-Goldstone bosons, can generate leptonic asymmetry in the universe, introducing a novel asymmetry source from a single decay process.

Contribution

It introduces a new mechanism for leptonic asymmetry generation involving right-handed neutrinos and light scalars, highlighting a unique decay process as a source of asymmetry.

Findings

Identification of a new asymmetry source from a single decay process

Potential for leptonic asymmetry generation via neutrino-light scalar interactions

Implications for baryogenesis and neutrino physics

Abstract

We consider a situation where right-handed neutrinos couple to a light scalar which is possibly a Nambu-Goldstone boson resulting from high-energy symmetry breaking. Its coupling is typically complex-valued and flavor-dependent. In this work, we investigate the possibility of the leptonic asymmetry generation in the Universe from the right-handed neutrino decay to flavorful light scalar. Furthermore a new source of asymmetry generation from a single decay process is pointed out, which is characteristic of the present setting.