Predictive Dirac neutrino spectrum with strong CP solution in SU(5)L × SU(5)R unification

Journal Article · Mon Apr 01 00:00:00 EDT 2024 · Journal of High Energy Physics (Online)

DOI:https://doi.org/10.1007/jhep04(2024)049· OSTI ID:2576010

Babu, K.; Mohapatra, Rabindra; Thapa, Anil

Abstract

We develop a grand unified theory of matter and forces based on the gauge symmetry SU(5)_L× SU(5)_Rwith parity interchanging the two factor groups. Our main motivation for such a construction is to realize a minimal GUT embedding of left-right symmetric models that provide a parity solution to the strong CP problem without the axion. We show how the gauge couplings unify with an intermediate gauge symmetry SU(3)_cL× SU(2)_2L× U(1)_L× SU(5)_R, and establish its consistency with proton decay constraints. The model correctly reproduces the observed fermion masses and mixings and leads tonaturally light Dirac neutrinoswith their Yukawa couplings suppressed by a factorM_I/M_G, the ratio of the intermediate scale to the GUT scale. We call this mechanism type II-Dirac seesaw. Furthermore, the model predictsδ_CP= ±(130.4±1.2)° and$$$${m}_{{\nu }_{1}}$$$$= (4.8 – 8.4) meV for the Dirac CP phase and the lightest neutrino mass. We demonstrate how the model solves the strong CP problem via parity symmetry.

• Research Organization: Oklahoma State Univ., Stillwater, OK (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: SC0016013
• OSTI ID: 2576010
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 4 Vol. 2024; ISSN 1029-8479
• Publisher: Springer Nature
• Country of Publication: United States
• Language: EN

Related Subjects

Physics