Current bounds on baryogenesis from complex Yukawa couplings of light fermions

TL;DR

This paper assesses how complex Yukawa couplings of light fermions could contribute to the Universe's baryon asymmetry, finding that charm quarks could account for about 1% of it under current experimental bounds.

Contribution

It provides the first quantitative bounds on baryogenesis contributions from light fermions' complex Yukawa couplings using effective field theory and electric dipole moment constraints.

Findings

Charm quark can generate up to 1% of the BAU.

Lighter quarks and electrons contribute negligibly.

Current experimental bounds limit the baryogenesis contribution from these sources.

Abstract

We calculate the contribution to the baryon asymmetry of the Universe (BAU) from a $\mathcal{CP}$-violating source of the light quarks (charm, strange, down, up) and the electron, resulting from a dimension-six effective field theory term. We derive relevant bounds from the electric dipole moments of the electron and neutron to estimate the maximal contribution from each single flavor modification. Current bounds show that the charm quark can generate at most $\mathcal{O}(1\%)$ of the BAU, while the lighter quarks and the electron contribute at much lower levels.