https://doi.org/10.1140/epjc/s10052-017-5437-x
Regular Article - Theoretical Physics
Tetraquark and two-meson states at large
1
Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, 1050, Vienna, Austria
2
D. V. Skobeltsyn Institute of Nuclear Physics, M. V. Lomonosov Moscow State University, 119991, Moscow, Russia
3
Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090, Vienna, Austria
4
IPNO, Université Paris-Sud, CNRS-IN2P3, Université Paris-Saclay, 91405, Orsay, France
* e-mail: sazdjian@ipno.in2p3.fr
Received:
26
October
2017
Accepted:
29
November
2017
Published online:
13
December
2017
Considering four-point correlation functions of color-singlet quark bilinears, we investigate, in the large- 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
-behaviors, consistently satisfy the constraints resulting from the
expansion procedure and thus provide a firm basis for the extraction of tetraquark properties from
-subleading diagrams. We find that, in general, tetraquarks, if they exist in compact form, should have narrow decay widths, of the order of
. 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.
© The Author(s), 2017