Understanding the systematic differences in extractions of the proton electric form factors at low Q2

Journal Article (Journal Article)

Systematic differences exist between values of the proton's electric form factors in the low-Q2 region extracted by different experimental and theoretical groups, though they are all making use of basically the same electron-proton scattering data. To try to understand the source of these differences, we make use of the analytically well-behaved rational (N=1, M=1) function, a predictive function that can be reasonably used for extrapolations at Q2→0. First, we test how well this deceptively simple two-parameter function describes the extremely complex and state-of-the-art dispersively improved chiral effective field theory calculations. Second, we carry out a complete re-analysis of the 34 sets of electron-proton elastic scattering cross-section data of the Mainz A1 Collaboration with its unconstrained 31 normalization parameters up to Q2=0.5(GeV/c)2. We find that subtle shifts in the normalization parameters can result in relatively large changes in the extracted physical qualities. In conclusion, we show that by simply using a well-behaved analytic function, the apparent discrepancy between recent form-factor extractions can be resolved.

Full Text

Duke Authors

Cited Authors

  • Zhou, J; Khachatryan, V; Gao, H; Gorbaty, S; Higinbotham, DW

Published Date

  • December 1, 2022

Published In

Volume / Issue

  • 106 / 6

Electronic International Standard Serial Number (EISSN)

  • 2469-9993

International Standard Serial Number (ISSN)

  • 2469-9985

Digital Object Identifier (DOI)

  • 10.1103/PhysRevC.106.065505

Citation Source

  • Scopus