The Vector and scalar form-factors of the pion to two loops

We calculate the vector and scalar form factors of the pion to two loops in Chiral Perturbation Theory. We estimate the unknown O(p^6) constants using resonance exchange. We make a careful comparison to the available data and determine two O(p^4) constants rather precisely, and two O(p^6) constants less precisely. We also use Chiral Perturbation Theory to two loops to extract in a model--independent manner the charge radius of the pion from the available data, and obtain \rpiV=0.437\pm 0.016 fm^2.

pi: form factor
form factor: vector
form factor: scalar
perturbation theory: chiral
higher-order: 2
symmetry: SU(3)
resonance: exchange
spontaneous symmetry breaking
numerical calculations: interpretation of experiments

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Figures(0)

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