Exotic states and their properties from large-n<sub>c</sub> qcd

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

The analysis of two-ordinary-meson scattering amplitudes in the limit of a large number, Nc, of the colour degrees of freedom of quantum chromodynamics, with suitably decreasing strong coupling and all quarks transforming according to the gauge group’s fundamental representation, enables us to establish a set of rigorous consistency conditions for the emergence of a tetraquark (i.e., a bound state of two quarks and two antiquarks) as a pole in these amplitudes. For genuinely flavour-exotic tetraquarks, these constraints require the existence of two tetraquark states distinguishable by their preferred couplings to two ordinary mesons, whereas, for cryptoexotic tetraquarks, our constraints may be satisfied by a single tetraquark state, which then, however, may mix with ordinary mesons. For elucidation of the tetraquark features, the consideration of the subleading contributions proves to be mandatory: For both variants of tetraquarks, their decay widths fall off like 1/Nc 2 for large Nc

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
314
No. of pages
4
DOI
https://doi.org/10.22323/1.314.0390
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/exotic-states-and-their-properties-from-largenc-qcd(0d65f0c6-9224-4e9e-88c1-c01819dfbb94).html