https://doi.org/10.1140/epja/s10050-021-00442-7
Regular Article –Theoretical Physics
Prediction of possible 
bound states
1
CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 100190, Beijing, China
2
School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
3
School of Physics, Central South University, 410083, Changsha, China
Received:
4
December
2020
Accepted:
28
March
2021
Published online:
20
April
2021
Stimulated by recent experimental observation of 
just below the 
threshold, we extend our previous study of 
S-wave bound state by vector meson exchange to system as well as similar 
, 
and systems to look for possible bound states. We find that the potential of 
is attractive and strong enough to form bound states with mass around 3110 MeV for 
and 3240 MeV for 
. 
is also attractive but weaker, hardly enough to form bound states. While becomes further less attractive, the potential between 
is the weakest, definitely too weak to form any bound state, which excludes the recently observed to be a bound state. We also give the decay properties of the predicted bound states.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
