Diffractive ηc and ηb productions by neutrinos via neutral currents

We report on a first theoretical study for neutrino-induced diffractive production of heavy pseudoscalar mesons ηc and ηb off a nucleon. Based on the factorization formalism for exclusive processes, we evaluate the forward diffractive production cross section in perturbative QCD in terms of the light-cone QQ(bar sign) wave functions (WFs) of ηc,b mesons and the gluon distribution of the nucleon. The light-cone WFs of the ηc (ηb) meson are constructed to satisfy the spin symmetry relations with those of the J/ψ (Υ) meson. The diffractive ηc production is governed by the axial-vector coupling of the longitudinally polarized Z boson to a QQ(bar sign) pair, and the resulting ηc production rate is larger than that for the J/ψ by one order of magnitude. We also discuss the production of bottomonium ηb, which shows up for a higher beam energy