English

The Strong CP Problem, String Theory and the Nelson-Barr Mechanism

High Energy Physics - Phenomenology 2007-05-23 v1

Abstract

We review recent work on the strong CP problem in the context of realistic string-inspired models. We discuss the various solutions, review the conjecture that CP is generally a gauged discrete symmetry in string theory and then consider models of the Nelson-Barr type. We note that squark non-degeneracy spoils the Nelson-Barr structure at the one loop level. We stress that string theory expectations, as well as naturalness arguments, make it very difficult to avoid the constraints on non-degeneracy.

Keywords

Cite

@article{arxiv.hep-ph/9307214,
  title  = {The Strong CP Problem, String Theory and the Nelson-Barr Mechanism},
  author = {R. G. Leigh},
  journal= {arXiv preprint arXiv:hep-ph/9307214},
  year   = {2007}
}

Comments

preprint SCIPP 93/14; 10 pages, latex format, uses epsf.tex for 2 figures, submitted separately via `uufiles'

R2 v1 2026-07-22T14:17:51.626Z