R. Beminiwattha

Publications (6)22.11 Total impact

• Article: Measurement of the Parity-Violating Asymmetry in Electron-Deuteron Scattering in the Nucleon Resonance Region

  D. Wang, K. Pan, R. Subedi, X. Deng, Z. Ahmed, K. Allada, K. A. Aniol, D. S. Armstrong, J. Arrington, V. Bellini, [......], P. A. Souder, R. Suleiman, V. Sulkosky, C. M. Sutera, W. A. Tobias, B. Waidyawansa, B. Wojtsekhowski, L. Ye, B. Zhao, X. Zheng
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  ABSTRACT: We report on parity-violating asymmetries in the nucleon resonance region measured using $5 - 6$ GeV longitudinally polarized electrons scattering off an unpolarized deuterium target. These results are the first parity-violating asymmetry data in the resonance region beyond the $\Delta(1232)$, and provide a verification of quark-hadron duality in the nucleon electroweak $\gamma Z$ interference structure functions at the 10-15% level. The results are of particular interest to models relevant for calculating the $\gamma Z$ box-diagram corrections to elastic parity-violating electron scattering measurements.
  04/2013;
• Source

  Available from: John Robert Arrington

  Article: New Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei

  S. Abrahamyan, A. Acha, A. Afanasev, Z. Ahmed, H. Albataineh, K. Aniol, D. S. Armstrong, W. Armstrong, J. Arrington, T. Averett, [......], Y. Ye, Z. Ye, V. Yim, L. Zana, X. Zhan, J. Zhang, Y. Zhang, X. Zheng, V. Ziskin, P.Zhu
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  ABSTRACT: We have measured the beam-normal single-spin asymmetry An in the elastic scattering of 1–3 GeV transversely polarized electrons from 1H and for the first time from 4He, 12C, and 208Pb. For 1H, 4He, and 12C, the measurements are in agreement with calculations that relate An to the imaginary part of the two-photon exchange amplitude including inelastic intermediate states. Surprisingly, the 208Pb result is significantly smaller than the corresponding prediction using the same formalism. These results suggest that a systematic set of new An measurements might emerge as a new and sensitive probe of the structure of heavy nuclei.
  Physical Review Letters 11/2012; 109:192501. · 7.37 Impact Factor
• Article: Measurement of the neutron radius of 208Pb through parity violation in electron scattering.

  S Abrahamyan, Z Ahmed, H Albataineh, K Aniol, D S Armstrong, W Armstrong, T Averett, B Babineau, A Barbieri, V Bellini, [......], H Yao, Y Ye, Z Ye, V Yim, L Zana, X Zhan, J Zhang, Y Zhang, X Zheng, P Zhu
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  ABSTRACT: We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.
  Physical Review Letters 03/2012; 108(11):112502. · 7.37 Impact Factor
• Source

  Available from: Antonio Giusa

  Article: New precision limit on the strange vector form factors of the proton.

  Z Ahmed, K Allada, K A Aniol, D S Armstrong, J Arrington, P Baturin, V Bellini, J Benesch, R Beminiwattha, F Benmokhtar, [......], D Wang, J Wexler, R Wilson, B Wojtsekhowski, X Zhan, X Yan, H Yao, L Ye, B Zhao, X Zheng
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  ABSTRACT: The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.
  Physical Review Letters 03/2012; 108(10):102001. · 7.37 Impact Factor
• Source

  Available from: Piotr Decowski

  Article: Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

  S. Abrahamyan, Z. Ahmed, H. Albataineh, K. Aniol, D. S. Armstrong, W. Armstrong, T. Averett, B. Babineau, A. Barbieri, V. Bellini, [......], H. Yao, Y. Ye, Z. Ye, V. Yim, L. Zana, X. Zhan, J. Zhang, Y. Zhang, X. Zheng, P. Zhu
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  ABSTRACT: We report the first measurement of the parity-violating asymmetry A_PV in the elastic scattering of polarized electrons from 208Pb. A_PV is sensitive to the radius of the neutron distribution (Rn). The result A_PV = 0.656 \pm 0.060 (stat) \pm 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.
  01/2012;
• Source

  Available from: Piotr Decowski

  Article: New Precision Limit on the Strange Vector Form Factors of the Proton

  HAPPEX collaboration, Z. Ahmed, K. Allada, K. A. Aniol, D. S. Armstrong, J. Arrington, P. Baturin, V. Bellini, J. Benesch, R. Beminiwattha, [......], D Wang, J. Wexler, R Wilson, B Wojtsekhowski, X Zhan, X Yan, H Yao, L. Ye, B Zhao, X Zheng
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  ABSTRACT: The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV and beam energy E =3.48 GeV to be A_PV = -23.80 +/- 0.78 (stat) +/- 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G_E^s + 0.517 G_M^s = 0.003 +/- 0.010 (stat) +/- 0.004 (syst) +/- 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.
  07/2011;