Hadron Spectroscopy (theory): Diquarks, Tetraquarks, Pentaquarks and no quarks

Abstract

States beyond those expected in the simple constituent quark model are now emerging. I focus on the scalar glueball and its mixing with states in the $q\bar{q}$ nonet, and also on correlations in Strong QCD that may form diquarks and seed $qq\bar{q}\bar{q}$ states. Some models of the pentaquark candidate $\Theta (1540)$ are critically discussed.

Comments: Plenary talk at ICHEP04