Fermion Masses and Mixings in String Theory with Dirac Neutrinos

TL;DR

This paper identifies two string theory models within a specific supersymmetric landscape that successfully reproduce all fermion masses and mixings, including Dirac neutrino masses consistent with experimental and theoretical constraints.

Contribution

It presents the first explicit string-derived models that accurately match all fermion masses and mixings, including Dirac neutrinos, within the Pati-Salam framework.

Findings

Two dual models with maximal adjoint scalars reproduce fermion masses.

Dirac neutrino masses are in normal ordering, consistent with experiments.

Models satisfy both experimental data and swampland constraints.

Abstract

Analyzing the supersymmetric Pati-Salam landscape on a $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold in IIA string theory, we have found only two models that accurately account for all standard model fermion masses and mixings. The models are dual to each other under the exchange of two SU(2) sectors and feature 12 adjoint scalars, the maximum number allowed in the landscape, whose linear combination yields the two light Higgs eigenstates. Dirac neutrino-masses in normal ordering $(50.6,~10.6,~6.2)\pm 0.1$~meV satisfying both the experimental as well as swampland constraints.