Flavour structure of supersymmetric SO(10) GUTs with extended matter sector

TL;DR

This paper explores the flavor structure of supersymmetric SO(10) GUTs with extended matter sectors, demonstrating that adding multiple vector multiplets allows for successful fits to quark and lepton data and making specific predictions for neutrino mixing parameters.

Contribution

It provides a detailed analysis showing that multiple vector matter multiplets are necessary for realistic flavor fits in SO(10) GUTs and predicts observable neutrino mixing features.

Findings

Adding a second vector multiplet enables successful flavor fits.

Predicted non-zero leptonic 1-3 mixing angle near current experimental limit.

Small leptonic Dirac CP phase is favored by the model.

Abstract

We discuss in detail the flavour structure of the supersymmetric SO(10) grand unified models with the three traditional 16-dimensional matter spinors mixed with a set of extra 10-dimensional vector multiplets which can provide the desired sensitivity of the SM matter spectrum to the GUT symmetry breakdown at the renormalizable level. We put the qualitative argument that a successful fit of the quark and lepton data requires an active participation of more than a single vector matter multiplet on a firm, quantitative ground. We find that the strict no-go obtained for the fits of the charged sector observables in case of a single active matter 10 is relaxed if a second vector multiplet is added to the matter sector and excellent, though non-trivial, fits can be devised. Exploiting the unique calculable part of the neutrino mass matrix governed by the SU(2)_L triplet in the 54-dimensional Higgs multiplet, a pair of genuine predictions of the current setting is identified: a non-zero value of the leptonic 1-3 mixing close to the current 90% C.L. limit and a small leptonic Dirac CP phase are strongly preferred by all solutions with the global-fit chi^2-values below 50.