Measurement of the Neutron Electric Form Factor G E , n in the Quasifree H 2</…
1999; American Physical Society; Volume: 83; Issue: 2 Linguagem: Inglês
10.1103/physrevlett.83.276
ISSN1092-0145
AutoresM. Ostrick, C. Herberg, H. G. Andresen, J. R. M. Annand, Kurt Aulenbacher, Jan Becker, P. Drescher, D. Eyl, A. Frey, P. Grabmayr, Péter Hartmann, T. Hehl, W. Heil, J. Hoffmann, D. G. Ireland, J. D. Kellie, F. Klein, K. Livingston, Ch. Nachtigall, A. Natter, Ernst W. Otten, R.O. Owens, E. Reichert, D. Rohe, H. Schmieden, R. Sprengard, Michael L. Steigerwald, K. Steffens, Th. Walcher, R. Watson,
Tópico(s)Atomic and Molecular Physics
ResumoThe electric form factor of the neutron ${G}_{E,n}$ has been measured in the quasifree ${}^{2}\mathrm{H}(\stackrel{\ensuremath{\rightarrow}}{e}{,e}^{\ensuremath{'}}\stackrel{\ensuremath{\rightarrow}}{n})p$ reaction using the 855 MeV polarized cw electron beam of the Mainz Microtron MAMI. The polarization of the scattered neutrons was analyzed in a polarimeter consisting of two walls of plastic scintillators. The precession of the neutron spin in a magnetic field was used for the first time to circumvent the measurement of the effective analyzing power of the polarimeter and the beam polarization. In this way ${G}_{E,n}$ could be determined with little model dependence and experimental uncertainties. The result ${G}_{E,n}(0.34\mathrm{GeV}{}^{2}/{c}^{2})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.0611\ifmmode\pm\else\textpm\fi{}{0.0069}_{\mathrm{stat}}({+0.0069}{\ensuremath{-}0.0055}{)}_{\mathrm{syst}}$ is larger than previously assumed.
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