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arXiv · hep-ph/9604294

Dispersion-theoretical analysis of the nucleon electromagnetic form factors: Inclusion of time-like data

H. -W. Hammer·Ulf-G. Meißner·D. Drechsel
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Abstract

We update a recent dispersion--theoretical fit to the nucleon electromagnetic form factors by including the existing data in the time--like region. We show that while the time--like data for the proton can be described consistently with the existing world space--like data, this is not the case for the neutron. Another measurement of the process $e^+ e^- \to \bar n n$ is called for. We furthermore sharpen the previous estimate of the separation between the perturbative and the non--perturbative regime, which is characterized by a scale parameter $Λ^2 \simeq 10\,$GeV$^2$.

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H. -W. Hammer, Ulf-G. Meißner, D. Drechsel. 1996-04-23. Dispersion-theoretical analysis of the nucleon electromagnetic form factors: Inclusion of time-like data. https://doi.org/10.1016/0370-2693(96)00865-9

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