Mass spectra for $qc\bar q\bar c$, $sc\bar s\bar c$, $qb\bar q\bar b$, $sb\bar s\bar b$ tetraquark states with $J^{PC}=0^{++}$ and $2^{++}$

摘要

We have studied the mass spectra of the hidden-charm/bottom $qc\bar q\bar c$,$sc\bar s\bar c$ and $qb\bar q\bar b$, $sb\bar s\bar b$ tetraquark states with$J^{PC}=0^{++}$ and $2^{++}$ in the framework of QCD sum rules. We constructten scalar and four tensor interpolating currents in a systematic way andcalculate the mass spectra for these tetraquark states. The $X^\ast(3860)$ maybe either an isoscalar tetraquark state or $\chi_{c0}(2P)$. If the$X^\ast(3860)$ is a tetraquark candidate, our results prefer the $0^{++}$option over the $2^{++}$ one. The $X(4160)$ may be classified as either thescalar or tensor $qc\bar q\bar c$ tetraquark state while the $X(3915)$ favors a$0^{++}$ $qc\bar q\bar c$ or $sc\bar s\bar c$ tetraquark assignment over thetensor one. The $X(4350)$ can not be interpreted as a $sc\bar s\bar c$tetraquark with either $J^{PC}=0^{++}$ or $2^{++}$.