Running of fermion observables in non-supersymmetric SO(10) models

Tommy Ohlsson,Marcus Pernow

doi:10.1007/jhep11(2018)028

Abstract

We investigate the complete renormalization group running of fermion observables in two different realistic non-supersymmetric models based on the gauge group SO(10) with intermediate symmetry breaking for both normal and inverted neutrino mass orderings. Contrary to results of previous works, we find that the model with the more minimal Yukawa sector of the Lagrangian fails to reproduce the measured values of observables at the electroweak scale, whereas the model with the more extended Yukawa sector can do so if the neutrino masses have normal ordering. The difficulty in finding acceptable fits to measured data is a result of the added complexity from the effect of an intermediate symmetry breaking as well as tension in the value of the leptonic mixing angle {theta}_{{}^{23}}^{ell } .

Highlights

JHEP11(2018)028 possible which have different renormalization group (RG) running of the gauge couplings, resulting in different values for the energy scales MI and MGUT [20, 21]
We investigate the complete renormalization group running of fermion observables in two different realistic non-supersymmetric models based on the gauge group SO(10) with intermediate symmetry breaking for both normal and inverted neutrino mass orderings
Contrary to results of previous works, we find that the model with the more minimal Yukawa sector of the Lagrangian fails to reproduce the measured values of observables at the electroweak scale, whereas the model with the more extended Yukawa sector can do so if the neutrino masses have normal ordering

Summary

Description of the minimal and extended models

We briefly outline the two models to which fits will be performed. More details on these models can be found in refs. [14, 17]. The two models are both nonsupersymmetric and based on the SO(10) gauge group In what follows, they are referred to as the minimal model and the extended model due to their difference in scalar representations (whether or not the 120H is included). Where the subscripts indicate which representation they originate from Since these are the only scalars involved in the breaking chains, we appeal to the extended survival hypothesis to assume that they are the only ones that are present at this scale [12, 19, 29]. The Yukawa coupling matrices YF(10), YF(126), YR(126), YF(,1120), and YF(,1220) are related to the ones appearing in the SO(10) Lagrangians by a set of matching conditions [20, 27, 30], for which we refer the reader to refs. In ref. [17], the correct RGEs can be found, which determine the evolution of the gauge and Yukawa couplings between MGUT and MI

SM-like Lagrangian

Parameter-fitting procedure

Results and discussion

Summary and conclusions