Strange cousin of Z_(c) (4020/4025) as a tetraquark state

Motivated by the analogous properties of Z_(c)(3900/3885)and Z_(cs)(3985/4000).we tentatively assign Z_(c)(4020=4025)as the AA^(-)-type hidden-charm tetraquark state with J^(PC)=1^(+-),where A denotes the axialvector diquark states,and explore AA^(-)-type tetraquark states without strange,with strange,and with hidden-strange via QCD sum rules in a consistent manner.We then explore the hadronic coupling constants in the two-body strong decays of tetraquark states without and with strange via QCD sum rules based on rigorous quark-hadron duality and acquire partial and total decay widths.The present calculations support assigning Z_(c)(4020=4025)as theAA^(-)-type tetraquark state with J^(PC)=1^(+-),while the predictions for its strange cousin Z_(cs)state can be confronted with experimental data in the future.