1108.5654 (B. Z. Kopeliovich et al.)

Nonperturbative features of the axial current    [PDF]

B. Z. Kopeliovich, Ivan Schmidt, M. Siddikov

We study the nonperturbative structure of the axial current and evaluate the two-point light-cone distribution amplitudes (DA) associated with the correlator \int d\xi exp(-iq\xi)<0|\bar{\psi}(x)\Gamma\psi(y)J_{\mu}^{5}(\xi)|0> within the instanton vacuum model in the leading order in O(1/N_c). 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 Q^2 < 1 GeV^2.

View original: http://arxiv.org/abs/1108.5654