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Title Precision Rosenbluth Measurement of the Proton Elastic Electromagnetic Form Factors and Their Ratio at Q^2=2.64, 3.20, and 4.10 GeV^2
Authors Issam Qattan
JLAB number JLAB-PHY-05-465
LANL number nucl-ex/0610006
Other number DOE/ER/40150-3829
Document Type(s) (Thesis) 
Supported by U.S. Naval Research: No
Supported by Jefferson Lab LDRD Funding: No
A PHD thesis
Advisor(s) :
   Ralph Segel (Northwestern University)
Publication Abstract: Due to the inconsistency in the results of the mupGEp / GMp ratio of the proton, as extracted from the Rosenbluth and recoil polarization techniques, high precision measurements of the e-p elastic scattering cross sections were made at Q^2 = 2.64, 3.20, and 4.10 GeV^2 . Protons were detected, in contrast to previous measurements where the scattered electrons were detected, which dramatically decreased " dependent systematic uncertainties and corrections. A single spectrometer measured the scattered protons of interest while simultaneous measurements at Q^2 = 0.5 GeV^2 were carried out using another spectrometer which served as a luminosity monitor in order to remove any uncertainties due to beam charge and target density uctuations. The absolute uncertainty in the measured cross sections is ~3% for both spectrometers and with relative uncertainties, random and slope, below 1% for the higher Q^2 protons, and below 1% random and 6% slope for the monitor spectrometer. The extracted electric and magnetic form factors were determined to 4%-7% for GEp and 1.5% for GMp . The ratio mupGEp / GMp was determined to 4%-7% and showed mupGEp / GMp ~ 1.0. The results of this work are in agreement with the previous Rosenbluth data and inconsistent with high-Q^2 recoil polarization results, implying a systematic difference between the two techniques.
Experiment Numbers: E01-001
Group: Hall A
Document: pdf
Accepted Manuscript:
Supporting Documents:
Supporting Datasets: