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Title: Precise determination of the proton magnetic radius from electron scattering data

Abstract

We extract the proton magnetic radius from high-precision electron-proton elastic scattering cross section data. Our theoretical framework combines dispersion analysis and chiral effective field theory and implements the dynamics governing the shape of the low- Q 2 form factors. It allows us to use data up to Q 2 0.5 GeV 2 for constraining the radii and overcomes the difficulties of empirical fits and Q 2 0 extrapolation. We obtain a magnetic radius r M p = 0.850 ± 0.001 ( 1 σ fit uncertainty) - 0.004 + 0.009 (full-range theory uncertainty) fm, significantly different from earlier results obtained from the same data using empirical fits, and close to our extracted electric radius r E p = 0.842 ± 0.002 ( 1 σ fit uncertainty) - 0.002 + 0.005 (full-range theory uncertainty) fm.

Authors:
ORCiD logo; ORCiD logo;
Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP); Spanish MECD
OSTI Identifier:
1664508
Alternate Identifier(s):
OSTI ID: 1666368
Report Number(s):
JLAB-THY-20-3149; DOE/OR/23177-4926; arXiv:2002.05167
Journal ID: ISSN 2469-9985; PRVCAN; 035203
Grant/Contract Number:  
AC05-06OR23177; FPA2016-77313-P
Resource Type:
Published Article
Journal Name:
Physical Review C
Additional Journal Information:
Journal Name: Physical Review C Journal Volume: 102 Journal Issue: 3; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Charge distributions; effective field theory; electroweak interactions in nuclear physics; Lepton induced nuclear reactions; photonuclear reactions; quantum electrodynamics; neutrons; protons; chiral symmetry; form factors; magnetic moment; nonperturbative methods

Citation Formats

Alarcón, J. M., Higinbotham, D. W., and Weiss, C. Precise determination of the proton magnetic radius from electron scattering data. United States: N. p., 2020. Web. https://doi.org/10.1103/PhysRevC.102.035203.
Alarcón, J. M., Higinbotham, D. W., & Weiss, C. Precise determination of the proton magnetic radius from electron scattering data. United States. https://doi.org/10.1103/PhysRevC.102.035203
Alarcón, J. M., Higinbotham, D. W., and Weiss, C. Mon . "Precise determination of the proton magnetic radius from electron scattering data". United States. https://doi.org/10.1103/PhysRevC.102.035203.
@article{osti_1664508,
title = {Precise determination of the proton magnetic radius from electron scattering data},
author = {Alarcón, J. M. and Higinbotham, D. W. and Weiss, C.},
abstractNote = {We extract the proton magnetic radius from high-precision electron-proton elastic scattering cross section data. Our theoretical framework combines dispersion analysis and chiral effective field theory and implements the dynamics governing the shape of the low-Q2 form factors. It allows us to use data up to Q2≈0.5GeV2 for constraining the radii and overcomes the difficulties of empirical fits and Q2→0 extrapolation. We obtain a magnetic radius rMp=0.850±0.001 (1σ fit uncertainty) -0.004+0.009 (full-range theory uncertainty) fm, significantly different from earlier results obtained from the same data using empirical fits, and close to our extracted electric radius rEp=0.842±0.002 (1σ fit uncertainty) -0.002+0.005 (full-range theory uncertainty) fm.},
doi = {10.1103/PhysRevC.102.035203},
journal = {Physical Review C},
number = 3,
volume = 102,
place = {United States},
year = {2020},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1103/PhysRevC.102.035203

Figures / Tables:

FIG. 1 FIG. 1: Data: Mainz A1 electron-proton elastic scattering cross section data, with the normalization of the sets determined by our fit (in the higher energy bins, the plots show the data up to Q2 = 0.5 GeV2). Bands: Theoretical model (DIχEFT) with parameters ($r^{p}_{E}$ , $r^{p}_{M}$ ) obtained from ourmore » best fit. The bands show the range of the model predictions obtained by varying the parameters in the 1σ confidence interval of the fit; it does not include the theoretical uncertainty of the model. Both data and model are divided by the cross section evaluated with the standard dipole FFs.« less

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Works referenced in this record:

Reinterpretation of Classic Proton Charge Form Factor Measurements
journal, February 2020

  • Mihovilovič, Miha; Higinbotham, Douglas W.; Bevc, Melisa
  • Frontiers in Physics, Vol. 8
  • DOI: 10.3389/fphy.2020.00036

Consistency of electron scattering data with a small proton radius
journal, June 2016


Theoretical constraints and systematic effects in the determination of the proton form factors
journal, January 2015


Evaluation of the strength of electron-proton scattering data for determining the proton charge radius
journal, January 2016


Extraction of the proton radius from electron-proton scattering data
journal, July 2015


Muonic Hydrogen and the Proton Radius Puzzle
journal, October 2013


The Rydberg constant and proton size from atomic hydrogen
journal, October 2017


Nucleon form factors in dispersively improved chiral effective field theory: Scalar form factor
journal, November 2017


Electric and magnetic form factors of the proton
journal, July 2014


Model independent extraction of the proton magnetic radius from electron scattering
journal, October 2014


Review of Particle Physics
journal, August 2020

  • Zyla, P. A.; Barnett, R. M.; Beringer, J.
  • Progress of Theoretical and Experimental Physics, Vol. 2020, Issue 8
  • DOI: 10.1093/ptep/ptaa104

Accurate nucleon electromagnetic form factors from dispersively improved chiral effective field theory
journal, September 2018


Proton and neutron electromagnetic form factors and uncertainties
journal, February 2018


Reexamining the proton-radius problem using constrained Gaussian processes
journal, May 2019


Nucleon form factors in dispersively improved chiral effective field theory. II. Electromagnetic form factors
journal, May 2018


High-Precision Determination of the Electric and Magnetic Form Factors of the Proton
journal, December 2010


Proton charge radius extraction from electron scattering data using dispersively improved chiral effective field theory
journal, April 2019


Proton radius from electron scattering data
journal, May 2016


How analytic choices can affect the extraction of electromagnetic form factors from elastic electron scattering cross section data
journal, July 2020

  • Barcus, Scott K.; Higinbotham, Douglas W.; McClellan, Randall E.
  • Physical Review C, Vol. 102, Issue 1
  • DOI: 10.1103/PhysRevC.102.015205

The structure of the nucleon: Elastic electromagnetic form factors
journal, July 2015


The size of the proton
journal, July 2010

  • Pohl, Randolf; Antognini, Aldo; Nez, François
  • Nature, Vol. 466, Issue 7303
  • DOI: 10.1038/nature09250

The proton radius puzzle
journal, May 2015


Dispersion analysis of the nucleon form factors including meson continua
journal, March 2007


Generalized parton distributions
journal, December 2003


Proton radius from electron-proton scattering and chiral perturbation theory
journal, March 2017


Reexamination of proton rms radii from low- q power expansions
journal, January 2017


The size of the proton: Closing in on the radius puzzle
journal, November 2012

  • Lorenz, I. T.; Hammer, H. -W.; Meißner, Ulf-G.
  • The European Physical Journal A, Vol. 48, Issue 11
  • DOI: 10.1140/epja/i2012-12151-1

Defining the proton radius: A unified treatment
journal, March 2019


A small proton charge radius from an electron–proton scattering experiment
journal, November 2019


Proton electromagnetic form factors: Basic notions, present achievements and future perspectives
journal, January 2015


Evaluation of low-Q2 fits to ep and ed elastic scattering data
journal, July 2020


Theory of light hydrogenlike atoms
journal, February 2001


Unraveling hadron structure with generalized parton distributions
journal, October 2005


New Measurement of the 1 S 3 S Transition Frequency of Hydrogen: Contribution to the Proton Charge Radius Puzzle
journal, May 2018


A measurement of the atomic hydrogen Lamb shift and the proton charge radius
journal, September 2019


Evaluation of the Proton Charge Radius from Electron–Proton Scattering
journal, September 2015

  • Arrington, John; Sick, Ingo
  • Journal of Physical and Chemical Reference Data, Vol. 44, Issue 3
  • DOI: 10.1063/1.4921430

    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.