Completing constrained flavor violation: lepton masses, neutrinos and leptogenesis

TL;DR

This paper evaluates the constrained flavor violation (CFV) framework's ability to predict lepton masses and neutrino properties, proposing extensions to include neutrinos and leptogenesis, with potential implications for low-scale exotic decays.

Contribution

It assesses the viability of CFV for lepton mass predictions, extends CFV to neutrinos, and explores implications for leptogenesis and exotic decays.

Findings

CFV faces challenges in accurately predicting lepton mass ratios.

Extension of CFV to neutrinos yields predictions for hierarchical heavy neutrinos.

N2 leptogenesis and low-scale leptoquark decays are possible within the extended framework.

Abstract

Constrained flavor violation is a recent proposal for predicting the down-quark Yukawa matrix in terms of those for up quarks and charged leptons. We study the viability of CFV with respect to its predictions for the lepton mass ratios, showing that this remains a challenge, and suggest some possible means for improving this shortcoming. We then extend CFV to include neutrinos, and show that it leads to interesting predictions for hierachical heavy neutrinos, and leptogenesis dominated by decays of the second heaviest one ("N2 leptogenesis"), as well as the possibility of low-scale leptoquark-mediated exotic decays.