X(3860) production in association with $$J/\psi $$ via $$e^{+}e^{-}$$ annihilation at Belle

Abstract

AbstractIn this paper, we study the X(3860) production associated with $$J/\psi $$ J / ψ via $$e^{+}e^{-}$$ e + e - annihilation at the next-to-leading-order (NLO) accuracy in $$\alpha _s$$ α s , within the nonrelativistic QCD (NRQCD) framework. With the hypothesis of $$J^{PC}_{X(3860)}=0^{++}$$ J X ( 3860 ) PC = 0 + + , the predictions of $$\sigma _{e^{+}e^{-} \rightarrow J/\psi +X(3860)}$$ σ e + e - → J / ψ + X ( 3860 ) agree well with the Belle measurements, whereas the results following the $$2^{++}$$ 2 + + assignment significantly undershoot the data. This is consistent with the Belle’s conclusion that the $$0^{++}$$ 0 + + hypothesis is favored over the $$2^{++}$$ 2 + + hypothesis for X(3860). Despite fitting the data of the total cross section, the NRQCD predictions seem to be incompatible with the measured $$J/\psi $$ J / ψ angular distributions. We simultaneously calculate the cross section of $$e^{+}e^{-} \rightarrow J/\psi +X(3940)$$ e + e - → J / ψ + X ( 3940 ) under the assumption of $$J^{PC}_{X(3940)}=0^{-+}$$ J X ( 3940 ) PC = 0 - + , discovering the consistency of the NRQCD predictions with the light-cone results as well as the experiment.