Nonperturbative features of the axial current

We study the nonperturbative structure of the axial current and evaluate the two-point light-cone distribution amplitudes (DA) associated with the correlator ∫dξe−iq⋅ξ〈0|ψ¯(x)Γψ(y)Jμ5(ξ)|0〉 within the instanton vacuum model in the leading order in O(Nc). Due to the built-in chiral symmetry, four of eight axial DAs are related to that for pions. Knowledge of these nonperturbative objects is important for phenomenological study of high-energy neutrino interactions and semileptonic decays of heavy quarks. We provide a code for evaluation of these DAs and an interpolation formula valid in the region Q2≲1 GeV2.