English

Explicit parametrization of more than one vector-like quark of Nelson-Barr type

High Energy Physics - Phenomenology 2023-09-01 v1

Abstract

Nelson-Barr models solve the strong CP problem based on spontaneous CP violation and generically requires vector-like quarks (VLQs) mixing with standard quarks to transmit the CP violation. We devise an explicit parametrization for the case of two VLQs of either down-type or up-type and quantitatively study several aspects including the hierarchy of the VLQ Yukawas and their irreducible contribution to θˉ\bar{\theta}. In particular, with the use of the parametrization, we show that a big portion of the parameter space for two up-type VLQs at the TeV scale is still allowed by the constraint on θˉ\bar{\theta}, although this case had been previously shown to be very restricted based on estimates.

Keywords

Cite

@article{arxiv.2304.06078,
  title  = {Explicit parametrization of more than one vector-like quark of Nelson-Barr type},
  author = {G. H. S. Alves and A. L. Cherchiglia and C. C. Nishi},
  journal= {arXiv preprint arXiv:2304.06078},
  year   = {2023}
}