Interpretation of Axial Resonances in J/psi-phi at LHCb

Abstract

We suggest that the J/psi phi structures observed by LHCb can be fitted in two tetraquak multiplets, the S-wave ground state and the first radial excitation, with composition [cs][cbar sbar]. When compared to the previously identified [cq][cbar qbar] multiplet, the observed masses agree with what expected for a multiplet with q -->s. We propose the X(4274), fitted by LHCb with a single 1^++ resonance, to correspond rather to two, almost degenerate, unresolved lines with J^PC = 0^++, 2^++. Masses of missing particles in the 1S and 2S multiplets are predicted.

3 pages, 1 figure, to appear in PRD