{
  "id": "nucl-ex/0307001",
  "version": "v1",
  "published": "2003-06-30T20:56:02.000Z",
  "updated": "2003-06-30T20:56:02.000Z",
  "title": "Measurements of the electromagnetic form factor of the Proton at JLab",
  "authors": [
    "Vina Punjabi",
    "Charles Perdrisat",
    "Jefferson Lab Hall A Collaboration",
    "GEp-III Collaboration"
  ],
  "comment": "10 pages, 6 figures, presented at Xth International Seminar on Electromagnetic Interactions of Nuclei at Low and Medium Energies, INP, RAS, Moscow, 16-18 April, 2003, will appear in the proceedings",
  "categories": [
    "nucl-ex"
  ],
  "abstract": "The ratio of the proton's elastic electromagnetic form factors $G_{Ep}/G_{Mp}$ was obtained by measuring $P_{t}$ and $P_{\\ell}$, the transverse and longitudinal recoil proton polarization, respectively. For the elastic reaction $\\vec e p \\to e\\vec p$, $G_{Ep}/G_{Mp}$ is proportional to $P_t/P_{\\ell}$. The simultaneous measurement of $P_{t}$ and $P_{\\ell}$ in a polarimeter reduces systematic uncertainties. The results for the ratio $G_{Ep}/G_{Mp}$ measured in Hall A so far show a systematic decrease with increasing $Q^2$, indicating for the first time a definite difference in the distribution of charge and magnetization in the proton. Together these experiments cover the Q$^{2}$- range of 0.5 to 5.6 GeV$^{2}$. A new experiment is currently being prepared, to extend the Q$^2$-range to 9 GeV$^2$ in Hall C.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2003-06-30T20:56:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "measurement",
      "protons elastic electromagnetic form factors",
      "polarimeter reduces systematic uncertainties",
      "longitudinal recoil proton polarization",
      "elastic reaction"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 622460,
      "adsabs": "2003nucl.ex...7001P"
    }
  }
}