W.K.H. Panofsky Prize in Experimental Particle Physics: It wasn't only about \textit{CP}, or even $B$ mesons

Although the primary motivation and design theme for the $B$-factories and their experiments was the study of \textit{CP} violations in the $b$-quark sector and testing the Kobayashi-Maskawa suggestion that \textit{CP} violation could be incorporated into the Standard Model as an irreducible complex phase in the weak-interaction quark-flavor mixing matrix, both the BaBar and Belle research programs made a number of important measurements that had nothing to do with either \textit{CP} violation or the $b$-quark sector. These include the unexpected discovery of $D^{0}-D^{0}$\textit{bar} mixing and a number of charmoniumlike mesons with properties that do not match expectations for conventional charmed-quark anticharmed-quark (\textit{ccbar}) mesons. In principle, these state, which are now commonly known as the\textit{ XYZ} mesons, are described in the Standard Model by the long-distance regime of QCD, but, since first-principle long-distance QCD calculations are hopelessly difficult, a number of ``QCD-inspired'' models for nonstandard mesons have been proposed. Some of these attribute the \textit{XYZ} states to loosely bound meson-antimeson molecule-like structures, and others to tightly bound diquark-diantiquark tetraquarks, or quark-antiquark-gluon hybrids. None of the proposed models can give a comprehensive description of the spectrum of the observed states and their measured properties. In this talk I describe a few of the \textit{XYZ} mesons found by BaBar and Belle and why they are considered to be nonstandard. In addition I suggest some future measurements that could be done at BESIII, BelleII and Panda that might establish patterns that may help decipher some of the mysteries of long-distance QCD. Supported by project code IBS-R016-D