# Fits to Non-Supersymmetric SO(10) Models with Type I and II Seesaw Mechanisms Using Renormalization Group Evolution

## TL;DR

This paper performs detailed numerical fits of non-supersymmetric SO(10) models with type I and II seesaw mechanisms, analyzing their compatibility with current neutrino data and making predictions for observables like neutrinoless double beta decay.

## Contribution

It introduces a comprehensive top-down fitting approach incorporating renormalization group evolution for non-supersymmetric SO(10) models with combined seesaw mechanisms, identifying viable parameter regions.

## Key findings

- Acceptable fits only for normal neutrino mass ordering.
- Type-I seesaw dominance preferred in the best fits.
- Predictions made for neutrinoless double beta decay and CP violation.

## Abstract

We consider numerical fits to non-supersymmetric $\mathrm{SO}(10)$-based models in which neutrino mass is generated by the type-I or type-II seesaw mechanism or a combination of both. The fits are performed with a sophisticated top-down procedure, taking into account the renormalization group equations of the gauge and Yukawa couplings, integrating out relevant degrees of freedom at their corresponding mass scales, and using recent data for the Standard Model observables. We find acceptable fits for normal neutrino mass ordering only and with neutrino mass generated by either type-I seesaw only or a combination of types I and II seesaw in which type-I seesaw is dominant. Furthermore, we find predictions from the best fit regarding the small neutrino masses, the effective neutrinoless double beta decay mass, and the leptonic CP-violating phase. Finally, we show that the fits are rather insensitive to the chosen value of the unification scale.