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Title: Determination of the pion charge form factor for Q{sup 2}= 0.60-1.60 GeV{sup 2}

Abstract

The data analysis for the reaction {sup 1}H(e,e{sup '}{pi}{sup +})n, which was used to determine values for the charged pion form factor F{sub {pi}} for values of Q{sup 2}= 0.6-1.6 GeV{sup 2}, has been repeated with careful inspection of all steps and special attention to systematic uncertainties. Also the method used to extract F{sub {pi}} from the measured longitudinal cross section was critically reconsidered. Final values for the separated longitudinal and transverse cross sections and the extracted values of F{sub {pi}} are presented.

Authors:
; ;  [1]; ;  [2];  [3]; ; ; ;  [4]; ; ; ; ; ; ; ; ; ;  [5] more »;  [5];  [6] « less
  1. Yerevan Physics Institute, 375036 Yerevan (Armenia)
  2. Faculteit Natuur-en Sterrenkunde, Vrije Universiteit, NL-1081 HV Amsterdam (Netherlands)
  3. (Netherlands)
  4. University of Regina, Regina, Saskatchewan S4S-0A2 (Canada)
  5. Physics Division, TJNAF, Newport News, Virginia 23606 (United States)
  6. (United States) (and others)
Publication Date:
OSTI Identifier:
20995322
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.75.055205; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CROSS SECTIONS; DATA ANALYSIS; FORM FACTORS; HYDROGEN 1; PIONS

Citation Formats

Tadevosyan, V., Mkrtchyan, H., Stepanyan, S., Blok, H. P., Volmer, J., NIKHEF, Postbus 41882, NL-1009 DB Amsterdam, Huber, G. M., Brash, E. J., Lolos, G. J., Meer, R. L. J. van der, Abbott, D., Dunne, J., Ent, R., Liang, M., Lung, A., Mack, D. J., Mitchell, J., Vulcan, W., Wood, S., Yan, C., Anklin, H., and Florida International University, Miami, Florida 33119. Determination of the pion charge form factor for Q{sup 2}= 0.60-1.60 GeV{sup 2}. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.055205.
Tadevosyan, V., Mkrtchyan, H., Stepanyan, S., Blok, H. P., Volmer, J., NIKHEF, Postbus 41882, NL-1009 DB Amsterdam, Huber, G. M., Brash, E. J., Lolos, G. J., Meer, R. L. J. van der, Abbott, D., Dunne, J., Ent, R., Liang, M., Lung, A., Mack, D. J., Mitchell, J., Vulcan, W., Wood, S., Yan, C., Anklin, H., & Florida International University, Miami, Florida 33119. Determination of the pion charge form factor for Q{sup 2}= 0.60-1.60 GeV{sup 2}. United States. doi:10.1103/PHYSREVC.75.055205.
Tadevosyan, V., Mkrtchyan, H., Stepanyan, S., Blok, H. P., Volmer, J., NIKHEF, Postbus 41882, NL-1009 DB Amsterdam, Huber, G. M., Brash, E. J., Lolos, G. J., Meer, R. L. J. van der, Abbott, D., Dunne, J., Ent, R., Liang, M., Lung, A., Mack, D. J., Mitchell, J., Vulcan, W., Wood, S., Yan, C., Anklin, H., and Florida International University, Miami, Florida 33119. Tue . "Determination of the pion charge form factor for Q{sup 2}= 0.60-1.60 GeV{sup 2}". United States. doi:10.1103/PHYSREVC.75.055205.
@article{osti_20995322,
title = {Determination of the pion charge form factor for Q{sup 2}= 0.60-1.60 GeV{sup 2}},
author = {Tadevosyan, V. and Mkrtchyan, H. and Stepanyan, S. and Blok, H. P. and Volmer, J. and NIKHEF, Postbus 41882, NL-1009 DB Amsterdam and Huber, G. M. and Brash, E. J. and Lolos, G. J. and Meer, R. L. J. van der and Abbott, D. and Dunne, J. and Ent, R. and Liang, M. and Lung, A. and Mack, D. J. and Mitchell, J. and Vulcan, W. and Wood, S. and Yan, C. and Anklin, H. and Florida International University, Miami, Florida 33119},
abstractNote = {The data analysis for the reaction {sup 1}H(e,e{sup '}{pi}{sup +})n, which was used to determine values for the charged pion form factor F{sub {pi}} for values of Q{sup 2}= 0.6-1.6 GeV{sup 2}, has been repeated with careful inspection of all steps and special attention to systematic uncertainties. Also the method used to extract F{sub {pi}} from the measured longitudinal cross section was critically reconsidered. Final values for the separated longitudinal and transverse cross sections and the extracted values of F{sub {pi}} are presented.},
doi = {10.1103/PHYSREVC.75.055205},
journal = {Physical Review. C, Nuclear Physics},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • The data analysis for the reaction {sup 1}H(e,e{prime}{pi}{sup +})n, which was used to determine values for the charged pion form factor F{sub {pi}} for values of Q{sup 2} = 0.6-1.6 GeV{sup 2}, has been repeated with careful inspection of all steps and special attention to systematic uncertainties. Also the method used to extract F{sub {pi}} from the measured longitudinal cross section was critically reconsidered. Final values for the separated longitudinal and transverse cross sections and the extracted values of F{sub {pi}} are presented.
  • The data analysis for the reaction H(e,e{prime} pi{sup +})n, which was used to determine values for the charged pion form factor Fpi for values of Q2 = 0.6-1.6 (gEv/C){sup 2}, has been repeated with careful inspection of all steps and special attention to systematic uncertainties. Also the method used to extract Fpi from the measured longitudinal cross section was critically reconsidered. Final values for the separated longitudinal and transverse cross sections and the extracted values of Fpi are presented.
  • The {sup 1}H(e,e{sup '}{pi}{sup +})n cross section was measured at four-momentum transfers of Q{sup 2}=1.60 and 2.45 GeV{sup 2} at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F{sub {pi}}) was extracted from the data by comparing the separated longitudinal pion electroproduction cross section to a Regge model prediction in which F{sub {pi}} is a free parameter. The results indicate that the pion form factor deviates from the charge-radius constrained monopole form at these values of Q{sup 2} by one sigma, but is still far from its perturbative quantum chromodynamics prediction.
  • The charged pion form factor, F{sub {Pi}}(Q{sup 2}), is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of F{sub {Pi}} from data requires a model of the {sup 1}H(e,e'{Pi}+)n reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for F{sub {Pi}} are presented for Q{sup 2} = 0.60-2.45 GeV2. Above Q{sup 2}=1.5GeV{sup 2}, the F{sub {Pi}} values aremore » systematically below the monopole parametrization that describes the low Q{sup 2} data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard contributions to hadronic structure in the intermediate Q{sup 2} regime.« less
  • The charged pion form factor, F{sub {pi}}(Q{sup 2}), is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of F{sub {pi}} from data requires a model of the {sup 1}H(e,e{sup '}{pi}{sup +})n reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for F{sub {pi}} are presented for Q{sup 2}=0.60-2.45 GeV{sup 2}. Above Q{sup 2}=1.5 GeV{sup 2}, the F{sub {pi}}more » values are systematically below the monopole parametrization that describes the low Q{sup 2} data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard contributions to hadronic structure in the intermediate Q{sup 2} regime.« less