Proton generalized parton distributions from electromagnetic form factors: A theoretically constrained phenomenological reconstruction
Abstract
We present a theoretically constrained phenomenological reconstruction of the unpolarized, chiral-even, leading-twist proton generalized parton distributions Hq and Eq. At zero skewness, valence-quark distributions are combined with flavor-dependent exponential profiles calibrated simultaneously against phenomenological representations of the proton and neutron electromagnetic form factors. The construction imposes exact valence and anomalous-magnetic-moment normalizations, the low-scale condition Bu+d(0)=0, the required endpoint behavior, and the complete Gaussian impact-parameter positivity bound. The resulting parametrization provides a reasonable description of the electromagnetic form factors and their slopes while revealing the tension between strict GPD consistency and a precision reproduction of all low-Q2 observables within the adopted ansatz. We extend the distributions to nonzero skewness using normalized double distributions and introduce an independent D-term to complete the relevant Mellin polynomials. We examine electromagnetic and energy--momentum-tensor form factors, impact-parameter distributions, positivity, polynomiality, and illustrative mechanical properties. The analysis distinguishes information constrained by electromagnetic data from additional assumptions governing skewness and the mechanical sector, thereby providing a transparent elastic baseline for future studies of nucleon-to-resonance transition GPDs.
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BibTeX
@misc{capeloastudillo2026proton,
title = {{Proton generalized parton distributions from electromagnetic form factors: A theoretically constrained phenomenological reconstruction}},
author = {A. Capelo-Astudillo and T. Aguilar and M. Conde-Correa and A. Duenas-Vidal and P. G. Ortega and J. Segovia},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.05635},
eprint = {2611.05635},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.05635},
}
RIS
TY - UNPB
TI - Proton generalized parton distributions from electromagnetic form factors: A theoretically constrained phenomenological reconstruction
AU - A. Capelo-Astudillo
AU - T. Aguilar
AU - M. Conde-Correa
AU - A. Duenas-Vidal
AU - P. G. Ortega
AU - J. Segovia
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.05635
UR - https://arxiv.org/abs/2611.05635
AB - We present a theoretically constrained phenomenological reconstruction of the unpolarized, chiral-even, leading-twist proton generalized parton distributions H^q and E^q. At zero skewness, valence-quark distributions are combined with flavor-dependent exponential profiles calibrated simultaneously against phenomenological representations of the proton and neutron electromagnetic form factors. The construction imposes exact valence and anomalous-magnetic-moment normalizations, the low-scale condition B^u+d(0)=0, the required endpoint behavior, and the complete Gaussian impact-parameter positivity bound. The resulting parametrization provides a reasonable description of the electromagnetic form factors and their slopes while revealing the tension between strict GPD consistency and a precision reproduction of all low-Q^2 observables within the adopted ansatz. We extend the distributions to nonzero skewness using normalized double distributions and introduce an independent D-term to complete the relevant Mellin polynomials. We examine electromagnetic and energy--momentum-tensor form factors, impact-parameter distributions, positivity, polynomiality, and illustrative mechanical properties. The analysis distinguishes information constrained by electromagnetic data from additional assumptions governing skewness and the mechanical sector, thereby providing a transparent elastic baseline for future studies of nucleon-to-resonance transition GPDs.
ER -