Neutrinos as Windows Into Physics Beyond the Standard Model

We investigate several possible routes for extending the Standard Model of Particle Physics, based on phenomenological considerations. We focus particularly on the role of neutrino data, proton decay bounds and known fermion masses and mixing angles in constraining a viable model. First, we discuss the symmetry structure necessary to explain a light sterile neutrino. We show that such a particle would imply the existence of an extended sterile sector. Second, we describe the minimal Trinified Model. We detail the structure of vacuum expectation values and couplings necessary to reproduce the standard model and analyze the predicted proton decay rate. Third, we consider Planck scale induced proton decay operators. We discuss to what extent the choice of unified gauge group can suppress these operators, and show that they can be sufficiently suppressed in E6, or trinified models. However, this implies an intermediate scale. Next, we consider a pair of successful models in SO(10). Here we demonstrate the potential role of a new higher-dimensional operator as an extension or alternative to these models. Last, we describe the constraints imposed on unified model building by the neutrino data in conjunction with naturalness principles. We show that such constraints imply highly non-generic forms for the neutrino Yukawa coupling matrices.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Sayre, Joshua Coe

Contributors dc:contributor

• Scott Willenbrock

• Physics, Theory

Language dc:language

eng

Identifier

(MiAaPQ)AAI3314884

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/80570