Dispersion-theoretical analysis of the electromagnetic form factors of the nucleon: Past, present and future

We review the dispersion-theoretical analysis of the electromagnetic form factors of the nucleon. We emphasize in particular the role of unitarity and analyticity in the construction of the isoscalar and isovector spectral functions. We present new results on the extraction of the nucleon radii, the electric and magnetic form factors and the extraction of omega-meson couplings. All this is supplemented by a detailed calculation of the theoretical uncertainties, using bootstrap and Bayesianmethods to pin down the statistical errors, while systematic errors are determined from variations of the spectral functions. We also discuss the physics of the time-like form factors and point out further issues to be addressed in this framework.

Automated summary

This review focuses on the dispersion-theoretical analysis of the electromagnetic form factors of the nucleon, highlighting the importance of unitarity and analyticity in constructing isoscalar and isovector spectral functions. New results on nucleon radii, electric and magnetic form factors, and omega-meson couplings are presented, with detailed calculations of theoretical uncertainties using bootstrap and Bayesian methods. Physics of time-like form factors are discussed, with further issues to be addressed in this framework.