NEW HADRON STATES

Abstract

In the past four years we have witnessed the renaissance of the hadron spectroscopy. Many interesting new hadron states were discovered experimentally, some of which do not fit into the quark model easily. I will give a concise overview of these states and their possible interpretations. Topics covered in this review are: (1) candidates of new light hadrons including [Formula: see text] threshold enhancement, X(1835), X(1576), f0(1810), recent candidates of the 1-+ exotic mesons, Y(2175), [Formula: see text] threshold enhancement etc. (2) charmed mesons including p-wave non-strange charmed mesons, Dsj(2317) and Dsj(2460), recent candidates of higher excited charmed mesons, Dsj(2632) etc. (3) charmonium and charmonium-like states such as X(3872), Y(4260), X(3940), Y(3940), Z(3930) etc. The effect from the nearby S-wave open channels on the quark model spectrum above or near strong decay threshold is emphasized. Dynamical lattice simulations of DK and [Formula: see text] scattering and the extraction of their phase shifts may help resolve the underlying structure of Dsj(2317), Dsj(2460) and X(3872).