2014/11/30 by Angelo Esposito, Andrea L. Guerrieri, Fulvio Piccinini +2 · 1 citation
Physics and Astronomy · #Field (mathematics) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Phenomenology (philosophy) #Quantum Chromodynamics and Particle Interactions #State (computer science) #Work (physics) #hep-ph
paper · pdf · doi:10.1142/s0217751x15300021
published as Int. J. Mod. Phys. A 30, 1530002 (2015) · 120 pages, 53 figures. Several typos corrected and some refs. added in v2
arxiv created 2014/12/29 · openalex publication_date 2015/01/16 · arxiv updated 2015/02/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The past decade witnessed a remarkable proliferation of exotic charmonium-like resonances discovered at accelerators. In particular, the recently observed charged states are clearly not interpretable as [Formula: see text] mesons. Notwithstanding the considerable advances on the experimental side, conflicting theoretical descriptions do not seem to provide a definitive picture about the nature of the so-called XYZ particles. We present here a comprehensive review about this intriguing topic, discussing both those experimental and theoretical aspects which we consider relevant to make further progress in the field. At this state of progress, XYZ phenomenology speaks in favor of the existence of compact four-quark particles (tetraquarks) and we believe that realizing this instructs us in the quest for a firm theoretical framework.