July 31, 2018 to August 6, 2018
Maynooth University
Europe/Dublin timezone

Exotic states and their properties in large-Nc QCD

Aug 3, 2018, 5:00 PM
Hall A (Arts Bldg.)

Hall A

Arts Bldg.

Talk B: Light quarks Light quarks


Dmitri Melikhov (HEPHY)


Discussing four-point Green functions of bilinear quark currents in large-Nc QCD, we formulate rigorous criteria for selecting diagrams appropriate for the analysis of potential tetraquark poles. We find that both flavor-exotic and cryptoexotic (i.e., flavor-nonexotic) tetraquarks, if such poles exist, have a width of order O(1/Nc²), so they are parametrically narrower compared to the ordinary qq mesons, which have a width of order O(1/Nc). Moreover, for flavor-exotic states, the consistency of the large-Nc behavior of “direct” and “recombination” Green functions requires two narrow flavor-exotic states, each coupling dominantly to one specific meson-meson channel.

Primary authors

Wolfgang Lucha (Austrian Academy of Sciences) Dmitri Melikhov (HEPHY) Hagop Sazdjian (University Paris-Sud)

Presentation materials