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Title: Robust extraction of the proton charge radius from electron-proton scattering data

Abstract

Background: Extracting the proton charge radius from electron scattering data requires determining the slope of the charge form factor at Q 2 15 of zero. But as experimental data never reach that limit, numerous methods for making the extraction have been proposed, though often the functions are determined after seeing the data which can lead to confirmation bias. Purpose: To find functional forms that will allow for a robust extraction of the input radius for a wide variety of functional forms in order to have confidence in the extraction from upcoming low Q 2 experimental data such as the Jefferson Lab PRad experiment. Method: We create a general framework for inputting form-factor functions as well as various fitting functions. The input form factors are used to generate pseudo-data with fluctuations intended to mimic the binning and random uncertainty of a given set of real data. All combinations of input functions and fit functions can then be tested repeatedly against regenerated pseudo-data. Since the input radius is known, this allows us to find those functions that are robust for radius extractions in an objective fashion. Results: For the range and uncertainty of the PRad data, we find that a two-parameter rationalmore » function, a two-parameter continued fraction and the second order polynomial expansion of z can extract the input radius regardless of the input charge form factor function that is used. Conclusions: We have created an easily expandable framework to search for functional forms that allow for a robust extraction of the radius from a given binning and uncertainty of pseudo-data generated from a wide variety of trial functions. This method has enabled a successful search for the best functional forms to extract the radius from the upcoming PRad data, and can be used for other experiments.« less

Authors:
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [2];  [1];  [1]
  1. Duke Univ., Durham, NC (United States); triangle Univ. Nuclear Lab., Durham, NC (United States)
  2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  3. Mississippi State Univ., Mississippi State, MS (United States)
  4. Duke Univ., Durham, NC (United States); triangle Univ. Nuclear Lab., Durham, NC (United States); Duke Kunchan Univ., Jiangsu (China)
  5. North Carolina A & T State Univ., Greensboro, NC (United States)
  6. Idaho State Univ., Pocatello, ID (United States)
  7. Univ. of Virginia, Charlottesville, VA (United States)
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) (SC-26)
OSTI Identifier:
1466730
Alternate Identifier(s):
OSTI ID: 1465610
Report Number(s):
JLAB-PHY-18-2655; DOE/OR/23177-4361; arXiv:1803.01629
Journal ID: ISSN 2469-9985; PRVCAN
Grant/Contract Number:  
AC05-060R23177; FG02-03ER41231
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 98; Journal Issue: 2; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Yan, Xuefei, Higinbotham, Douglas W., Dutta, Dipangkar, Gao, Haiyan, Gasparian, Ashot, Khandaker, Mahbub A., Liyanage, Nilanga, Pasyuk, Eugene, Peng, Chao, and Xiong, Weizhi. Robust extraction of the proton charge radius from electron-proton scattering data. United States: N. p., 2018. Web. doi:10.1103/PhysRevC.98.025204.
Yan, Xuefei, Higinbotham, Douglas W., Dutta, Dipangkar, Gao, Haiyan, Gasparian, Ashot, Khandaker, Mahbub A., Liyanage, Nilanga, Pasyuk, Eugene, Peng, Chao, & Xiong, Weizhi. Robust extraction of the proton charge radius from electron-proton scattering data. United States. doi:10.1103/PhysRevC.98.025204.
Yan, Xuefei, Higinbotham, Douglas W., Dutta, Dipangkar, Gao, Haiyan, Gasparian, Ashot, Khandaker, Mahbub A., Liyanage, Nilanga, Pasyuk, Eugene, Peng, Chao, and Xiong, Weizhi. Tue . "Robust extraction of the proton charge radius from electron-proton scattering data". United States. doi:10.1103/PhysRevC.98.025204.
@article{osti_1466730,
title = {Robust extraction of the proton charge radius from electron-proton scattering data},
author = {Yan, Xuefei and Higinbotham, Douglas W. and Dutta, Dipangkar and Gao, Haiyan and Gasparian, Ashot and Khandaker, Mahbub A. and Liyanage, Nilanga and Pasyuk, Eugene and Peng, Chao and Xiong, Weizhi},
abstractNote = {Background: Extracting the proton charge radius from electron scattering data requires determining the slope of the charge form factor at Q2 15 of zero. But as experimental data never reach that limit, numerous methods for making the extraction have been proposed, though often the functions are determined after seeing the data which can lead to confirmation bias. Purpose: To find functional forms that will allow for a robust extraction of the input radius for a wide variety of functional forms in order to have confidence in the extraction from upcoming low Q2 experimental data such as the Jefferson Lab PRad experiment. Method: We create a general framework for inputting form-factor functions as well as various fitting functions. The input form factors are used to generate pseudo-data with fluctuations intended to mimic the binning and random uncertainty of a given set of real data. All combinations of input functions and fit functions can then be tested repeatedly against regenerated pseudo-data. Since the input radius is known, this allows us to find those functions that are robust for radius extractions in an objective fashion. Results: For the range and uncertainty of the PRad data, we find that a two-parameter rational function, a two-parameter continued fraction and the second order polynomial expansion of z can extract the input radius regardless of the input charge form factor function that is used. Conclusions: We have created an easily expandable framework to search for functional forms that allow for a robust extraction of the radius from a given binning and uncertainty of pseudo-data generated from a wide variety of trial functions. This method has enabled a successful search for the best functional forms to extract the radius from the upcoming PRad data, and can be used for other experiments.},
doi = {10.1103/PhysRevC.98.025204},
journal = {Physical Review C},
issn = {2469-9985},
number = 2,
volume = 98,
place = {United States},
year = {2018},
month = {8}
}

Journal Article:
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