Zcs(3985)- as the U-spin partner of Zc(3900)- and implication of other states in the SU(3)F symmetry and heavy quark symmetry

Recently, for the first time, the BESIII Collaboration reported the strange hidden charm tetraquark states Z(cs) (3985)(-) in the K+ recoil-mass spectrum near the Ds-D*(0)/D-s*D--(0) mass thresholds in the processes of e(+)e(-)-> K+(Ds-D*(0) + D-s*D--(0)) at root s = 4.681 GeV (M. Ablikim et al., arXiv:2011.07855). The significance was estimated to be 5.3a. We show that the newly observed Z(cs)(3985)(-) state is the U-spin partner of Z(c)(3900)(-) as a resonance within coupled-channel calculation in the SU(3)(F) symmetry and heavy quark spin symmetry (HQSS). In the SU(3)(F) symmetry, we introduce the G(U/V) parity to construct the flavor wave functions of the Z(cs) states. In a unified framework, we consider the J/psi pi(K), (D) over bar ((s))*/(D) over bar*D-(s) coupled-channel effect with the contact interaction. With the masses and widths of Z(c)(3900) and Z(c)(4020), we determine all the unknown coupling constants. We obtain mass and width of Z(c)(3985) in good agreement with the experimental results, which strongly support the Z(cs) states as the U/V-spin partner states of the charged Z(c)(3900). We also calculate the ratio of the partial decay widths of Z(c)(3985), which implies that the (D) over bar ((s))*/(D) over bar*D-(s) decay modes are dominant. We also predict the Z(')cs states with a mass around 4130 MeV and width around 30 MeV, which are the U/V-spin partner states of the charged Z(c)(4020) and HQSS partner states of the Z(c)(3985). In the hidden bottom sector, we predict the strange tetraquark states Z(bs) and Z'(bs) with a mass around 10700 and 10750 MeV, which are the U/V-spin partner states of Z(b)(10610)(+/-) and Z(b)(10650)(+/-), respectively.