Speaker
Hagop Sazdjian
(University Paris-Sud)
Description
The question of the existence of compact tetraquarks is studied in the large-$N_c$ limit of QCD. Considering the fully exotic case, corresponding to four different quark flavors, it is shown that consistency conditions of correlation functions of color-singlet bilinear currents require the existence of two different tetraquarks, each decaying preferentially into a single two-meson channel. On the other hand, the diquark scheme, which provides the mechanism for producing compact tetraquarks, gives rise to one tetraquark bound state. This contradiction suggests that large-$N_c$ QCD does not support the existence of compact flavor-exotic tetraquarks.
Based on Phys. Rev. D 98 (2018) 094011.
Authors
Wolfgang Lucha
(Austrian Academy of Sciences)
Dmitri Melikhov
(HEPHY, Vienna, Austria and SINP, Moscow, Russia)
Hagop Sazdjian
(University Paris-Sud)
