Exotic Hadrons in the Constituent Quark Model

Exotic hadrons are important because their existence or absence can provideimportant clues to understanding how QCD makes hadrons from quarks and gluons.The first experimentally confirmed exotic will be the first hadron containingboth $qq$ and $\bar q q$ pairs and the first hadron containing color sextet andcolor octet pairs. Theoretical models are not very useful because there is noaccepted model for multiquark systems with color-space correlations. Theconstituent quark model is the only phenomenological model with predictivepower that has given experimentally tested universal predictions for bothmesons and baryons. This paper reviews its explanation for why there are nobound exotics and its guidance to the search for heavy-flavored exotictetraquarks and pentaquarks. A possible supersymmetry between mesons andbaryons leading to meson-baryon mass relations not easily obtained otherwise isdiscussed.Comment: 8 page