The XYZ mesons: what they aren't

Abstract

I discuss the properties of some representative $XYZ$ mesons in the context of the most commonly proposed models for their underlying nature.

Comments: 8 pages, 6 figures, write-up of talks given at Charm2018 in Novosibirsk, May 2018 and New Physics in the Flavor Sector Workshop in Nagoya, November 2018. To appear in the Charm2018 proceedings