Axial Anomaly and Light Cone Distributions

TL;DR

This paper discusses how axial anomaly imposes exact sum rules on transition form factors, offering constraints on distribution amplitudes, and examines potential small corrections in light of experimental data.

Contribution

It provides a rigorous non-perturbative QCD approach to axial anomaly effects on distribution amplitudes, valid beyond standard QCD factorization assumptions.

Findings

Exact sum rules derived from axial anomaly constrain distribution amplitudes.

Analysis of small non-OPE corrections relative to BABAR and BELLE data.

Discussion on the validity of the approach even when QCD factorization breaks down.

Abstract

Axial anomaly leads to exact sum rules for transition form factors providing the important constraints to respective distribution amplitudes. This rigorous NPQCD approach is valid even if QCD factorization is broken. The status of possible small non-OPE corrections to continuum in comparison to BABAR and BELLE data is discussed.