Scattering of 15.7-Mev Electrons by Nuclei

Lyman, E. M.; Hanson, A. O.; Scott, M. B.

doi:10.1103/physrev.84.626

Cited by 97 publications

(45 citation statements)

References 25 publications

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“…GEp are consistent with the dipole parameterization for Q 2 < 1 (GeV/c) 2 ; however, the data are less precise for Q 2 > 1 (GeV/c) 2 and a definitive statement regarding the high Q 2 behavior of GEp cannot be made simply via visual inspection of the data.…”

Section: Unpolarized Results For Gep and Gmpmentioning

confidence: 55%

“…2-7. Scaling is confirmed for Q 2 < 1 (GeV/c) 2 , but the data for Q 2 > 1 (GeV/c) 2 are not as precise. 1 Assumed scaling, GMp = I-pGEp, to extract the specified quantity.…”

Section: Unpolarized Results For Gep and Gmpmentioning

confidence: 88%

“…The origins of electron scattering can be traced to the early experiments conducted by Lyman, Hanson, and Scott [2] in 1951 with a 15.7 MeV electron beam extracted from a 20 MeV betatron at the University of Illinois. Cross sections were measured 41 for elastic scattering from aluminum, carbon, copper, gold, and silver nuclear targets, and on the basis of their measurements, Lyman, Hanson, and Scott concluded that the "... observed deviations from Coulomb scattering are consistent with the picture of a nuclear charge whose ... density distribution is uniform or possibly slightly greater at the center of the nucleus".…”

Section: Introductionmentioning

confidence: 99%

“…The proton electric and magnetic form factors have been been measured up to Q 2 values of -8 and 30 (GeV/c) 2 , respectively; however, as will be discussed in detail in the next chapter, measurements of the proton electric form factor are less precise than those of the magnetic form factor, and significant discrepancies exist between older and more recent measurements. The situation for the neutron is even less satisfying; due to the lack of a free neutron target (as the neutron beta-decays after approximately 15 minutes), the neutron form factors are known with significantly less precision than the proton form factors and existing measurements are restricted to considerably smaller ranges of Q 2 .…”

Section: Introductionmentioning

confidence: 99%

“…The focus of the remainder of this thesis is the proper description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2 H(e, e'il) scattering at three Q 2 values of 0.45, 1.13, and 1.45 (GeV/c) 2 . This experiment, conducted in Hall C of the Thomas…”

Section: Introductionmentioning

confidence: 99%

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The neutron electric form factor to Q² = 1.45 (GeV/c)²

Plaster¹

2004

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The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q 2 , the square of the fourmomentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon.Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity.Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2 H(e, e')lH scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q 2 values of 0.45, 1.13, and 1.45 (GeV/c) 2 , and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors. Next, I would like to thank those who I credit most for my development: Jim Kelly and Andrei Semenov. At times, I found Jim's extremely high standards and desire for rigor to be exasperating, especially during the development of our simulation code and discussions of formalism (e.g., the "dreaded" Wigner rotation!), but, in retrospect, I am glad that I was constantly challenged to do something in an even better way and never permitted to give up. Indeed, I didn't fully appreciate the rigor of our analysis until our results were final, but hindsight is always 20/20. Also, I thank Jim for numerous comments and suggestions on this thesis; it is much better and much more complete because of his many suggestions. Andrei was the true guru (read: czar) of our analysis efforts, and he instilled in me the importance of careful work.I especially appreciate Andrei's timely responses to the numerous questions I always had concerning the analysis and the various analysis tools that we used; if there was someone who was sure to know the answer, that person was Andrei. Without Andrei, our analysis efforts would never have gotten off the ground. I also offer thank...

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Section: Unpolarized Results For Gep and Gmpmentioning

confidence: 55%

“…2-7. Scaling is confirmed for Q 2 < 1 (GeV/c) 2 , but the data for Q 2 > 1 (GeV/c) 2 are not as precise. 1 Assumed scaling, GMp = I-pGEp, to extract the specified quantity.…”

Section: Unpolarized Results For Gep and Gmpmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations