Interpretation of axial resonances in J/ψ - φ at the LHCb

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][(c) over bar(s) over bar]. When compared to the previously identified [cq][[(c) over bar(q) over bar] multiplet, the observed masses agree with that 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.