Analysis of the $Z_{cs}(3985)$ as the axialvector tetraquark state

Abstract

In this paper, we choose the scalar and axialvector diquark operators in the color antitriplet as the fundamental building blocks to construct the four-quark currents and investigate the diquark-antidiquark type axialvector tetraquark states $c\bar{c}u\bar{s}$ in the framework of the QCD sum rules. The predicted tetraquark mass $M_Z=3.99\pm 0.09\mathrm{GeV}$ is in excellent agreement with the experimental value $3985.2_{-2.0}^{+2.1}\pm 1.7\mathrm{MeV}$ from the BESIII collaboration, which supports identifying the $Z_{cs}(3985)$ as the cousin of the $Z_c(3900)$ with the quantum numbers $J^{PC}=1^{+-}$. We take into account the light flavor $SU(3)$ mass-breaking effect to estimate the mass spectrum of the diquark-antidiquark type hidden-charm tetraquark states having the strangeness according to the previous works.

Comments: 13 pages, 4 figures