X,YandZStates

Abstract

Abstract. Many new states in the charmonium mass region were recently discovered by BaBar, Belle, CLEO-c, CDF, DØ, BESIII, LHCb and CMS Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states.

Meson Spectroscopy from Lattice QCD

“…various charmonium and bottomonium-like structures ("X, Y, Z 's") and the charm-strange D s0 (2317) [49,53], and there are also longer-standing puzzles such as the makeup of the light scalar mesons [55,57]. There has been a lot of theoretical work and speculation about their nature [6,50]-possibilities include tetraquarks (containing two quarks and two antiquarks), molecular states of hadrons, hadro-quarkonia and hybrid mesons (where the gluonic field is excited). States with exotic quantum numbers, i.e.…”