Constraints from the 1/N<sub>C</sub> expansion on properties of exotic tetraquark mesons

Author(s)
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Abstract

Scrutinizing the scattering of ordinary mesons in the limiting case of the number of colour degrees of freedom Nc of quantum chromodynamics approaching infinity, we formulate Feynman-diagram selection criteria and from these deduce rigorous self-consistency conditions for the manifestation of a tetraquark, a two-quark–two-antiquark bound state, as a pole in the corresponding amplitudes. Our constraints bear rather far-reaching consequences: In particular, all flavour-exotic tetraquarks, composed of four (anti)quarks of disparate flavour, must come in, at least, two variants differing in (and thus readily identifiable by) the large-Nc behaviour of their couplings to two ordinary mesons. Quite generally, irrespective of their flavour composition, all tetraquarks prove to be narrow. Their decay rates behave, for large Nc, like 1/Nc 2 and thus decrease faster than those of ordinary mesons.

Organisation(s)
Particle Physics
External organisation(s)
Österreichische Akademie der Wissenschaften (ÖAW), Lomonosov Moscow State University (MSU), Universität Wien, Univ Paris Diderot, Centre National de la Recherche Scientifique (CNRS), CNRS - National Institute for Biology (INSB), UDICE-French Research Universities, Universite de Paris, CNRS, Lab Epigenet & Destin Cellulaire, UMR7216
Journal
Proceedings of Science (PoS)
Volume
310
No. of pages
4
DOI
https://doi.org/10.22323/1.310.0233
Publication date
2018
Peer reviewed
Yes
Austrian Fields of Science 2012
103034 Particle physics
ASJC Scopus subject areas
General
Portal url
https://ucris.univie.ac.at/portal/en/publications/constraints-from-the-1nc-expansion-on-properties-of-exotic-tetraquark-mesons(ce914770-67e0-49c8-819d-e5cce413e47d).html