English

Fast-Rolling Relaxion

High Energy Physics - Phenomenology 2020-01-29 v2

Abstract

We discuss new mechanisms to stop the relaxion field during inflation. They can be realized in a generic model, including the original model but in a quite different parameter region. We consider a fast-rolling relaxion field, which can go over the bumps created by QCD-like dynamics. Then, in one of the mechanisms, we stop it with a parametric resonance of the Higgs field. The mechanisms are free from a super-Planckian field excursion or a gigantic number of e-folds of inflation. The relaxion has a mass around the weak scale and mixes with the Higgs boson, which enhances the testability of our mechanisms.

Keywords

Cite

@article{arxiv.1904.02545,
  title  = {Fast-Rolling Relaxion},
  author = {Masahiro Ibe and Yutaro Shoji and Motoo Suzuki},
  journal= {arXiv preprint arXiv:1904.02545},
  year   = {2020}
}

Comments

58 pages, 12 figures; added Appendix D; published version

R2 v1 2026-06-23T08:29:18.385Z