2014/11/28 by Stephen Lars Olsen · 3 citations
Physics and Astronomy · #Baryon #Exotic hadron #Glueball #Hadron #Hadron spectroscopy #High-Energy Particle Collisions Research #Meson #Particle physics theoretical and experimental studies #Pentaquark #Quantum Chromodynamics and Particle Interactions #Quark model #hep-ex #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1007/s11467-014-0449-6
published as Front. Phys. 10, 101401 (2015) · 34 pages, 22 figures, a review article that will appear in Frontiers of Physics
arxiv created 2014/11/28 · openalex publication_date 2014/12/02 · arxiv updated 2014/12/10 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
QCD-motivated models for hadrons predict an assortment of “exotic” hadrons that have structures that are more complex than the quark-antiquark mesons and three-quark baryons of the original quark-parton model. These include pentaquark baryons, the six-quark H -dibaryon, and tetraquark, hybrid and glueball mesons. Despite extensive experimental searches, no unambiguous candidates for any of these exotic configurations have been identified. On the other hand, a number of meson states, one that seems to be a proton-antiproton bound state, and others that contain either charmed-anticharmed quark pairs or bottom-antibottom quark pairs, have been recently discovered that neither fit into the quark-antiquark meson picture nor match the expected properties of the QCD-inspired exotics. Here I briefly review results from a recent search for the H -dibaryon, and discuss some properties of the newly discovered states -the proton-antiproton state and the so-called XY Z mesons- and compare them with expectations for conventional quark-antiquark mesons and the predicted QCD-exotic states.