Tetraquark and two-meson states at large N-c

Autor(en)
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Abstrakt

Considering four-point correlation functions of color-singlet quark bilinears, we investigate, in the large-N-c limit of QCD, the subleading diagrams that involve, in the s-channel of meson-meson scattering amplitudes, two-quark-two-antiquark intermediate states. The latter contribute, together with gluon exchanges, to the formation, at the hadronic level, of two-meson and tetraquark intermediate states. It is shown that the two-meson contributions, which are predictable, in general, from leading-order N-c-behaviors, consistently satisfy the constraints resulting from the 1/ Nc expansion procedure and thus provide a firm basis for the extraction of tetraquark properties from N-c-subleading diagrams. We find that, in general, tetraquarks, if they exist in compact form, should have narrow decay widths, of the order of N-c(-2). For the particular case of exotic tetraquarks, involving four different quark flavors, two different types of tetraquark are needed, each having a preferred decay channel, to satisfy the consistency constraints.

Organisation(en)
Teilchenphysik
Externe Organisation(en)
Österreichische Akademie der Wissenschaften (ÖAW), Lomonosov Moscow State University (MSU), Université Paris-Saclay, Universität Wien
Journal
European Physical Journal C
Band
77
Anzahl der Seiten
11
ISSN
1434-6044
DOI
https://doi.org/10.1140/epjc/s10052-017-5437-x
Publikationsdatum
12-2017
Peer-reviewed
Ja
ÖFOS 2012
103012 Hochenergiephysik
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/tetraquark-and-twomeson-states-at-large-nc(aee28cc0-efcf-4a43-ba09-8eeace765253).html