Abstract
We complete the set of QCD light-cone sum rules for transition form factors, deriving a new sum rule for the timelike-helicity form factor in terms of dipion distribution amplitudes. This sum rule, in the leading twist-two approximation, is directly related to the pion vector form factor. Employing a relation between and other form factors, we obtain also the longitudinal-helicity form factor . In this way, all four (axial-)vector form factors are predicted from light-cone sum rules with dipion distribution amplitudes. These results are valid for small dipion masses with large momentum.
- Received 25 August 2017
DOI:https://doi.org/10.1103/PhysRevD.96.051901
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