AbstractVery recently, the LHCb Collaboration observed distinct structures with the $$cc{\bar{c}}{\bar{c}}$$
c
c
c
¯
c
¯
in the $$J/\Psi $$
J
/
Ψ
-pair mass spectrum. In this work, we construct four scalar ($$J^{PC} = 0^{++}$$
J
PC
=
0
+
+
) $$[8_c]_{Q\bar{Q^\prime }}\otimes [8_c]_{Q^\prime {\bar{Q}}}$$
[
8
c
]
Q
Q
′
¯
⊗
[
8
c
]
Q
′
Q
¯
type currents to investigate the fully-heavy tetraquark state $$Q Q^\prime {\bar{Q}} \bar{Q^\prime }$$
Q
Q
′
Q
¯
Q
′
¯
in the framework of QCD sum rules, where $$Q=c, b$$
Q
=
c
,
b
and $$Q^\prime = c, b$$
Q
′
=
c
,
b
. Our results suggest that the broad structure around 6.2-6.8 GeV can be interpreted as the $$0^{++}$$
0
+
+
octet–octet tetraquark states with masses $$6.44\pm 0.11$$
6.44
±
0.11
GeV and $$6.52\pm 0.10$$
6.52
±
0.10
GeV, and the narrow structure around 6.9 GeV can be interpreted as the $$0^{++}$$
0
+
+
octet–octet tetraquark states with masses $$6.87\pm 0.11$$
6.87
±
0.11
GeV and $$6.96\pm 0.11$$
6.96
±
0.11
GeV, respectively. Extending to the b-quark sector,the masses of their fully-bottom partners are found to be around 18.38-18.59 GeV. Additionally, we also analyze the spectra of the $$[8_c]_{c{\bar{c}}}\otimes [8_c]_{b {\bar{b}}}$$
[
8
c
]
c
c
¯
⊗
[
8
c
]
b
b
¯
and $$[8_c]_{c{\bar{b}}}\otimes [8_c]_{b {\bar{c}}}$$
[
8
c
]
c
b
¯
⊗
[
8
c
]
b
c
¯
tetraquark states, which lie in the range of 12.51–12.74 GeV and 12.49–12.81 GeV, respectively.
SCALING RELATIONS IN THE PHENOMENOLOGY OF QCD SUM RULES FOR THE HEAVY QUARKONIUM