https://doi.org/10.1140/epjp/s13360-020-00741-w
Regular Article
Systematics of 
in a chiral constituent quark model
Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems, Nanjing Normal University, 210023, Nanjing, People’s Republic of China
Received:
7
April
2020
Accepted:
2
September
2020
Published online:
11
September
2020
Inspired by 
reported by LHCb Collaboration and X(5568) reported by D0 Collaboration, the (
) tetraquark states, are studied in the present work. With the help of Gaussian expansion method, two structures, diquark–antidiquark and meson–meson, with all possible color configurations are investigated systematically in a chiral quark model to search for the possible stable states. The results show that there is no bound state in the iso-vector system, while there are rather deep bound states in the iso-scalar 
, 
and 
systems. There are also several shallow bound states in 
system. Mixing two structures of diquark–antidiquark and meson–meson can introduce more attractions and convert some unbound iso-scalar states into shallow bound states. The large mass of the heavy quark is beneficial to the formation of the bound state. The separations between quarks are calculated to unravel the spacial structure of the system. We also compare our result with that of other approaches.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2020
