Analysis of the X(3960) and related tetraquark molecular states via the QCD sum rules

Abstract

In this work, we study the Dbar{D}, DD, Dbar{D}_s, DD_s, D_sbar{D}_s and D_sD_s tetraquark molecular states with the J^{PC}=0^{++} via the QCD sum rules. The prediction M_{D_sbar{D}_s} = 3.98pm 0.10, text {GeV} is in very good agreement with the experimental value M_{X(3960)} = 3956 pm 5pm 10 ,text {MeV} from the LHCb collaboration and supports assigning the X(3960) as the D_s^+D_s^- molecular state with the J^{PC}=0^{++}. We take account of our previous works on the four-quark states consisting of two color-neutral clusters and acquire the mass spectrum of the ground state hidden-charm and doubly-charm tetraquark molecular states.