Revisit the tetraquark candidates in the $J/\psi J/\psi$ mass spectrum

Abstract

In this article, we introduce a relative P-wave to construct the doubly-charm axialvector diquark operator, then take the doubly-charm axialvector (anti)diquark operator as the basic constituent to construct the scalar and tensor tetraquark currents to study the scalar, axialvector and tensor fully-charm tetraquark states with the QCD sum rules. We observe that the ground state $\tilde{A}\tilde{A}$ type tetraquark states and the first radial excited states of the $AA$ type tetraquark states have almost degenerated masses, where the $\tilde{A}$ and $A$ stand for the diquark operators with and without the relative P-wave respectively, the broad structure above the $J/\psi J/\psi$ threshold maybe consist of several diquark-antidiquark type fully-charm tetraquark states.