In a model where CP is spontaneously broken, the aspon model, it is shown by extending previous arguments about B decay and the value of Re(ϵ′/ϵ) in the kaon system, that the neutron electric dipole moment Dn is bounded from below by Dn≥10−29e.-cm.
@article{arxiv.hep-ph/9805489,
title = {Neutron Electric Dipole Moment and Spontaneous CP Breaking},
author = {Paul H. Frampton and Masayasu Harada},
journal= {arXiv preprint arXiv:hep-ph/9805489},
year = {2009}
}