A Grand-Unified Nelson-Barr Model
Abstract
We argue that the Nelson-Barr solution to the Strong CP Problem can be naturally realized in an E Grand-Unified Theory. The chiral SM fermions reside in three generations of E fundamentals together with heavy vectorlike down quarks, leptons doublets and right-handed neutrinos. CP is imposed on the Lagrangian and broken only spontaneously at high scales, leading to a mixing between chiral and vectorlike fields that allows to solve the Strong CP Problem through the Nelson-Barr mechanism. The main benefit of the E GUT structure is the predictivity in the SM fermion sector, and a perfect fit to all SM observables can be obtained despite being over-constrained. Definite predictions are made for the neutrino sector, with a Dirac CP phase that is correlated to the CKM phase, allowing to test this model in the near future.
Keywords
Cite
@article{arxiv.1802.08109,
title = {A Grand-Unified Nelson-Barr Model},
author = {Jakob Schwichtenberg and Paul Tremper and Robert Ziegler},
journal= {arXiv preprint arXiv:1802.08109},
year = {2018}
}
Comments
17 pages, 3 figures