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), Anuchin Research Institute and Museum of Anthropology, Universität Wien, Centre National De La Recherche Scientifique (CNRS)
- 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