HEPData Search

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Measurement of the neutral weak form factors of the proton.

The HAPPEX collaboration Aniol, K.A. ; Armstrong, D.S. ; Baylac, M. ; et al.

Phys.Rev.Lett. 82 (1999) 1096-1100, 1999.

Inspire Record 478059 DOI 10.17182/hepdata.31319

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point (theta_lab = 12.3 degrees and Q^2=0.48 (GeV/c)^2) is chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor G_E^s. 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 G_E^s + 0.39G_M^s = 0.023 +- 0.034 (stat) +- 0.022 (syst) +- 0.026 (delta G_E^n), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.

1 data table

Table 1

Longitudinally polarized beam. C=L and C=R means left- and right polarization. The second systematic uncertainty arises from the estimated uncertainty inthe neutron electromagnetic from factor.

Parity violation in elastic electron proton scattering and the proton's strange magnetic form-factor.

The SAMPLE collaboration Spayde, D.T. ; Averett, T. ; Barkhuff, D. ; et al.

Phys.Rev.Lett. 84 (2000) 1106-1109, 2000.

Inspire Record 507265 DOI 10.17182/hepdata.31230

We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak axial radiative corrections. The new measurement of A=-4.92 +- 0.61 +- 0.73 ppm provides a significant constraint on these quantities. The implications for the strange magnetic form factor are discussed in the context of theoretical estimates for the axial corrections.

1 data table

Table 1

Polarized beam. FORMFACTOR(NAME=GM_S) is the strange quark contribution. FORMFACTOR(NAME=GM_S) is in nucleon magnetic FF.

Measurement of the proton's neutral weak magnetic form factor.

The SAMPLE collaboration Mueller, B. ; Beck, D.H. ; Beise, E.J. ; et al.

Phys.Rev.Lett. 78 (1997) 3824-3827, 1997.

Inspire Record 440739 DOI 10.17182/hepdata.31349

We report the first measurement of the parity-violating asymmetry in elastic electron scattering from the proton. The asymmetry depends on the neutral weak magnetic form factor of the proton which contains new information on the contribution of strange quark-antiquark pairs to the magnetic moment of the proton. We obtain the value $G_M~Z= 0.34 \pm 0.09 \pm 0.04 \pm 0.05$ n.m. at $Q~2=0.1$ (GeV/c)${}~2$.

1 data table

Table 1

Polarized beam. FORMFACTOR(NAME=GZM) = (1/4)*(GM_P-GM_N) - SIN2TW*GM_P - (1/4)*GM_S, whereFORMFACTOR(NAME=GM_S) is the strange quark contribution. FORMFACTOR(NAME=GZM) and FORMFACTOR(NAME=GM_S) are in nucleon magnetic FF.

Measurement of the vector analyzing power in elastic electron proton scattering as a probe of double photon exchange amplitudes.

The SAMPLE collaboration Wells, S.P. ; Averett, T. ; Barkhuff, D. ; et al.

Phys.Rev.C 63 (2001) 064001, 2001.

Inspire Record 524209 DOI 10.17182/hepdata.31444

We report the first measurement of the vector analyzing power in inclusive transversely polarized elastic electron-proton scattering at Q^2 = 0.1 (GeV/c)^2 and large scattering angles. This quantity should vanish in the single virtual photon exchange, plane wave impulse approximation for this reaction, and can therefore provide information on double photon exchange amplitudes for electromagnetic interactions with hadronic systems. We find a non-zero value of A=-15.4+/-5.4 ppm. No calculations of this observable for nuclei other than spin 0 have been carried out in these kinematics, and the calculation using the spin orbit interaction from a charged point nucleus of spin 0 cannot describe these data.

1 data table

Table 1

Polarized beam.

Electron Scattering at 4-Degrees with Energies of 4.5-GeV - 20-GeV

Stein, S. ; Atwood, W.B. ; Bloom, Elliott D. ; et al.

Phys.Rev.D 12 (1975) 1884, 1975.

Inspire Record 100597 DOI 10.17182/hepdata.4669

This paper presents the results of the analysis of a single-arm inelastic-electron-scattering experiment at an angle of 4°. We present data on the turnon of scaling in the low-q2 region 0.1<q2<1.8, the neutron-proton comparison at large values of the scaling variable ω, resonance excitation, and the shadowing in scattering from heavy nuclei.

21 data tables

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Measurement of Elastic electron Scattering from the Proton at High Momentum Transfer

Arnold, R.G. ; Bosted, Peter E. ; Chang, C.C. ; et al.

Phys.Rev.Lett. 57 (1986) 174, 1986.

Inspire Record 228320 DOI 10.17182/hepdata.3133

We have performed absolute measurements of the differential cross section for elastic e−p scattering in the range of momentum transfer from Q2=2.9 to 31.3 (GeV/c)2. Combined statistical and systematic uncertainties in the cross-section measurements ranged from 3% at low Q2 to 19% at high Q2. These data have been used to extract the proton magnetic form factor GMp(Q2). The results show a smooth decrease of Q4GMp with momentum transfer above Q2=10 (GeV/c)2. These results are compared with recent predictions of perturbative QCD.

14 data tables

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Elastic electron - proton scattering at momentum transfers up t 245-F**-2

Albrecht, W ; Behrend, H.J. ; Brasse, F.W. ; et al.

Phys.Rev.Lett. 17 (1966) 1192, 1966.

Inspire Record 48841 DOI 10.17182/hepdata.3392

None

17 data tables

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Backward electron-deuteron scattering below 280 mev

Ganichot, D. ; Grossetete, B. ; Isabelle, D.B. ;

Nucl.Phys.A 178 (1972) 545-562, 1972.

Inspire Record 75366 DOI 10.17182/hepdata.8775

We measured the elastic and inelastic scattering of electrons on deuterium at 180° for four incident energies (70, 140, 210 and 280 MeV). The data were analysed with a technique allowing an accurate comparison between experiment and theory. We observed a good agreement for the inelastic data with the expected cross section, using the presently available models and nucleon form factors. The experimental elastic cross section is systematically larger than the predicted cross sections.

16 data tables

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Electrodisintegration of the Deuteron Around q2=3.5 F-2

Grossetete, B. ; Jullian, S. ; Lehmann, P. ;

Phys.Rev. 141 (1966) 1435-1440, 1966.

Inspire Record 944958 DOI 10.17182/hepdata.462

We have measured the absolute cross sections of the electron-deuteron scattering at q2=3.5 F−2 and obtained the complete inelastic spectrum. Three points for each spectrum are given with a 4% accuracy. The scattering angles, 60° and 130°, were chosen to allow the separation between electric and magnetic scattering. Calculations of radiative corrections were made in order to permit the comparison of the spectra with the inelastic-scattering theories.

20 data tables

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