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arXiv · hep-ph/0510382

Novel evaluation of the two-pion contribution to the nucleon isovector form factors

M. A. Belushkin·H. -W. Hammer·Ulf-G. Meißner
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Abstract

We calculate the two-pion continuum contribution to the nucleon isovector spectral functions drawing upon the new high statistics measurements of the pion form factor by the CMD-2, KLOE, and SND collaborations. The general structure of the spectral functions remains unchanged, but the magnitude increases by about 10%. Using the updated spectral functions, we calculate the contribution of the two-pion continuum to the nucleon isovector form factors and radii. We compare the isovector radii with simple rho-pole models and illustrate their strong underestimation in such approaches. Moreover, we give a convenient parametrization of the result for use in future form factor analyses.

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M. A. Belushkin, H. -W. Hammer, Ulf-G. Meißner. 2005-12-15. Novel evaluation of the two-pion contribution to the nucleon isovector form factors. https://doi.org/10.1016/j.physletb.2005.12.053

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