# A $\pmb{\nu}$ Solution to the Strong CP Problem

## TL;DR

This paper proposes a novel solution to the strong CP problem by introducing a tiny imaginary component to the up quark mass via a Dirac seesaw mechanism, linking it to neutrino masses and predicting measurable neutron EDM.

## Contribution

It introduces a new Dirac seesaw mechanism that generates a small imaginary up quark mass and connects it to neutrino masses, with a supersymmetric extension for stability.

## Key findings

- Neutron electric dipole moment is predicted to be within experimental reach.
- The model links the strong CP problem solution to neutrino mass generation.
- Supersymmetric extension stabilizes scalar mass hierarchy.

## Abstract

We present a new solution to the strong CP problem in which the imaginary component of the up quark mass, $\mathcal{I}[m_u]$, acquires a tiny, but non-vanishing value. This is achieved via a Dirac seesaw mechanism, which is also responsible for the generation of the small neutrino masses. Consistency with the observed value of the up quark mass is achieved via instanton contributions arising from QCD-like interactions. In this framework, the value of the neutron electric dipole moment is directly related to $\mathcal{I}[m_u]$, which, due to its common origin with the neutrino masses, implies that the neutron electric dipole moment is likely to be measured in the next round of experiments. We also present a supersymmetric extension of this Dirac seesaw model to stabilize the hierarchy among the scalar mass scales involved in this new mechanism.