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arXiv · 1012.4671

Light Cone Sum Rules for the pi0-gamma*-gamma Form Factor Revisited

S. S. Agaev·V. M. Braun·N. Offen·F. A. Porkert
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Abstract

We provide a theoretical update of the calculations of the pi0-gamma*-gamma form factor in the LCSR framework, including up to six polynomials in the conformal expansion of the pion distribution amplitude and taking into account twist-six corrections related to the photon emission at large distances. The results are compared with the calculations of the B-> pi l nu decay and pion electromagnetic form factors in the same framework. Our conclusion is that the recent BaBar measurements of the pi0-gamma*-gamma form factor at large momentum transfers are consistent with QCD, although they do suggest that the pion DA may have more structure than usually assumed.

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S. S. Agaev, V. M. Braun, N. Offen, F. A. Porkert. 2010-12-21. Light Cone Sum Rules for the pi0-gamma*-gamma Form Factor Revisited. https://doi.org/10.1103/physrevd.83.054020

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