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