Matter Unification and Lepton Flavour Violation

TL;DR

This paper investigates low-energy quark-lepton unification models with inverse seesaw neutrino masses, analyzing experimental constraints and highlighting the potential of upcoming muon conversion experiments to test these theories at the multi-TeV scale.

Contribution

It provides a minimal framework for matter unification at the TeV scale, incorporating inverse seesaw neutrino masses and assessing experimental bounds including meson decays and muon conversion.

Findings

Current meson decay limits constrain the unification scale.

Upcoming muon to electron conversion experiments can significantly probe the model.

The analysis accounts for unknown quark-lepton mixing angles.

Abstract

We explore the idea of quark-lepton unification at low energies. In particular, we discuss the minimal framework for matter unification at the multi-TeV scale, in which neutrino masses are necessarily generated via the inverse seesaw mechanism. To assess the testability of this theory for physics beyond the Standard Model, we analyze current experimental constraints and derive the corresponding lower bound on the symmetry breaking scale. We reexamine the impact of existing limits from lepton number violating meson decays, taking into account the freedom associated with unknown quark-lepton mixing angles. Furthermore, we study the correlation between bounds from meson decays and $\mu \to e$ conversion. We demonstrate that the upcoming $\mu \to e$ conversion experiment at Fermilab can play a crucial role in probing quark-lepton unification at the multi-TeV scale.