Measurement of the neutral weak form factors of the proton

K. A. Aniol, D. S. Armstrong, M. Baylac, E. Burtin, J. Calarco, G. D. Cates, C. Cavata, J. P. Chen, E. Chudakov, D. Dale, C. W. De Jager, A. Deur, P. Djawotho, M. B. Epstein, S. Escoffier, L. Ewell, N. Falletto, J. M. Finn, K. Fissum, A. FleckB. Frois, J. Gao, F. Garibaldi, A. Gasparian, G. M. Gerstner, R. Gilman, A. Glamazdin, J. Gomez, V. Gorbenko, O. Hansen, F. Hersman, R. Holmes, M. Holtrop, B. Humensky, S. Incerti, J. Jardillier, M. K. Jones, J. Jorda, C. Jutier, W. Kahl, D. H. Kim, M. S. Kim, K. Kramer, K. S. Kumar, M. Kuss, J. LeRose, M. Leuschner, D. Lhuillier, N. Liyanage, R. Lourie, R. Madey, D. J. Margaziotis, F. Marie, J. Martino, P. Mastromarino, K. McCormick, J. McIntyre, Z. E. Meziani, R. Michaels, G. W. Miller, D. Neyret, C. Perdrisat, G. G. Petratos, R. Pomatsalyuk, J. S. Price, D. Prout, V. Punjabi, T. Pussieux, G. Quéméner, G. Rutledge, P. M. Rutt, A. Saha, Paul A Souder, M. Spradlin, R. Suleiman, J. Thompson, L. Todor, P. E. Ulmer, B. Vlahovic, K. Wijesooriya, R. Wilson, B. Wojtsekhowski

Research output: Contribution to journalArticle

132 Scopus citations


We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point [〈θlab〉 = 12.3° and (Q2) = 0.48 (GeV/c)2] is chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor Gs E. The result, A = -14.5 ± 2.2 ppm, is consistent with the electroweak standard model and no additional contributions from strange quarks. In particular, the measurement implies Gs E + 0.39 Gs M = 0.023 ± 0.034(stat) ± 0.022(syst) ± 0.026(δGn E), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.

Original languageEnglish (US)
Pages (from-to)1096-1100
Number of pages5
JournalPhysical Review Letters
Issue number6
StatePublished - Feb 8 1999


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Aniol, K. A., Armstrong, D. S., Baylac, M., Burtin, E., Calarco, J., Cates, G. D., Cavata, C., Chen, J. P., Chudakov, E., Dale, D., De Jager, C. W., Deur, A., Djawotho, P., Epstein, M. B., Escoffier, S., Ewell, L., Falletto, N., Finn, J. M., Fissum, K., ... Wojtsekhowski, B. (1999). Measurement of the neutral weak form factors of the proton. Physical Review Letters, 82(6), 1096-1100.