New predictions on the mass of the $1^{-+}$ light hybrid meson from QCD sum rules

We calculate the coefficients of the dimension-8 quark and gluon condensates in the current-current correlator of $1^{-+}$ light hybrid current $gbar{q}(x)gamma_{ u}iG_{mu u}(x)q{(x)}$. With inclusion of these higher-power corrections and updating the input parameters, we re-analyze the mass of the $1^{-+}$ light hybrid meson from Monte-Carlo based QCD sum rules. Considering the possible violation of factorization of higher dimensional condensates and variation of $langle g^3G^3rangle$, we obtain a conservative mass range 1.72--2.60,GeV, which favors $pi_{1}(2015)$ as a better hybrid candidate compared with $pi_{1}(1600)$ and $pi_{1}(1400)$.