Proton Decay and the Origin of Quark and Lepton Mixing

TL;DR

This paper explores a grand unified theory linking quark and lepton flavor mixing to extra fermions, predicting neutrino properties and proton decay patterns, which can test the model's validity.

Contribution

It demonstrates that mixing angles within GUT fermion multiplets are predicted and proposes proton decay branching ratios as independent tests of the model.

Findings

Predicted neutrino masses and CP phases

Proton decay branching ratios as tests

Parameters determined from spectra and decay

Abstract

It was recently proposed that all flavor mixing has a single source, namely the mixing of the three quark and lepton families with "extra" vectorlike fermions in 5 + 5-bar multiplets of SU(5). This was shown to lead to several testable predictions including neutrino masses and CP-violating phases. Here it is shown that the mixing angles within grand unified fermion multiplets are also predicted. Proton decay branching ratios would thus give several independent tests of the model. Certain model parameters could be determined independently from the quark and lepton spectrum and from proton decay.