2016/01/25 by Matthew Severson, Severson, Matthew
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.1601.06478
openalex publication_date 2016/01/25 · openalex created_date 2020/01/10 · openalex updated_date 2026/07/28
This work presents a complete analysis of fermion fitting and proton decay in a SUSY SO(10) model previously suggested by Dutta, Mimura, and Mohapatra. A key question in any grand unified theory is whether it satisfies the experimental lower limits on proton partial lifetimes. In generic models, substantial fine-tuning is required among GUT-scale parameters to satisfy the limits. In the proposed model, the \bf 10, \bf126, and \bf 120 Yukawa couplings contributing to fermion masses have restricted textures intended to give favorable results for proton lifetime, while still giving rise to a realistic fermion sector, without the need for fine-tuning, even for large tanβ, and for either type-I or type-II dominance in the neutrino mass matrix. In this thesis, I investigate the above hypothesis at a strict numerical level of scrutiny; I obtain a valid fit for the entire fermion sector for both types of seesaw dominance, including θ13 in good agreement with the most recent data. For the case with type-II seesaw, I find that, using the Yukawa couplings fixed by the successful fermion sector fit, proton partial lifetime limits are readily satisfied for all but one of the pertinent decay modes for nearly arbitrary values of the triplet-Higgs mixing parameters, with the K+ ν mode requiring a \cal O(10-1) cancellation in order to satisfy its limit. I also find a maximum partial lifetime for that mode of τ(K+ ν) ∼ 1036 years. For the type-I seesaw case, I find that K+ ν decay mode is satisfied for any values of the triplet mixing parameters giving no major enhancement, and all other modes are easily satisfied for arbitrary mixing values; I also find a maximum partial lifetime for K+ ν of nearly 1038 years, which is sub-dominant to gauge boson decay channels.