Topics in Hadron Spectroscopy in 2009

Abstract

There have been numerous developments in hadron spectroscopy over the past year. In this brief review I focus on two general areas. In the first I give an update on hadrons with b-quarks. Their properties are in textbook agreement with QCD motivated constituent quark models. The second topic is the Charmonium-like $XYZ$ states above open charm threshold that continue to be discovered. Many of these do not seem to be described as conventional c\bar{c} states and may be hadronic molecules, Tetraquarks, or Charmonium Hybrids. The first topic is an example of how well we seem to understand hadrons while the second case reminds us of how much we still have to learn.