Z_cs , Z_c and Z_b states under the complex scaling method

We investigate the Z_b , Z_c and Z_cs states within the chiral effective field theory framework and the S -wave single channel molecule picture. With the complex scaling method, we accurately solve the Schrödinger equation in momentum space. Our analysis reveals that the Z_b(10610) , Z_b(10650) , Z_c(3900) and Z_c(4020) states are the resonances composed of the S -wave (BB̅^*+B^*B̅)/√(2) , B^*B̅^* , (DD̅^*+D^*D̅)/√(2) and D^*D̅^* , respectively. Furthermore, although the Z_cs(3985) and Z_cs(4000) states exhibit a significant difference in width, these two resonances may originate from the same channel, the S -wave (D_sD̅^*+D_s^*D̅)/√(2) . Additionally, we find two resonances in the S -wave D_s^*D̅^* channel, corresponding to the Z_cs(4123) and Z_cs(4220) states that await experimental confirmation.