Constraints from the 1/N_C expansion on properties of exotic tetraquark mesons

Autor(en)

Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian

Abstrakt

Scrutinizing the scattering of ordinary mesons in the limiting case of the number of colour degrees of freedom N_c 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-N_c 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 N_c, like 1/N_c ² and thus decrease faster than those of ordinary mesons.

Organisation(en)

Teilchenphysik

Externe Organisation(en)

Österreichische Akademie der Wissenschaften (ÖAW), Lomonosov Moscow State University (MSU), Universität Wien, Centre National De La Recherche Scientifique (CNRS)

Journal

Proceedings of Science (PoS)

Band

310

Anzahl der Seiten

4

DOI

https://doi.org/10.22323/1.310.0233

Publikationsdatum

2018

Peer-reviewed

Ja

ÖFOS 2012

103034 Teilchenphysik

ASJC Scopus Sachgebiete

General

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/ce914770-67e0-49c8-819d-e5cce413e47d