Backward scattering of positrons and electrons on protons

Bouquet, B. ; Benaksas, D. ; Grossetête, B. ; et al.
Phys.Lett.B 26 (1968) 178-180, 1968.
Inspire Record 1389620 DOI 10.17182/hepdata.29320

The ratio R = σ (e + + p)/ σ (e − + p) of the elastic scattering cross-section detecting the recoil proton at 0 o in coincidence with the backward electron or positron was found to be R = 1.036 ± 0.018 at q 2 = 8 fm −2 , R = 1.079 ± 0.046 at q 2 = 32 fm −2 .

2 data tables

Axis error includes +- 0.0/0.0 contribution (?////Errors presented are the total combined statistical and systematic error s. Radiative corrections applied).

Axis error includes +- 0.0/0.0 contribution (?////Errors presented are the total combined statistical and systematic error s. Radiative corrections applied).


Scattering of positrons and electrons from protons

Bartel, W. ; Dudelzak, B. ; Krehbiel, H. ; et al.
Phys.Lett.B 25 (1967) 242-245, 1967.
Inspire Record 1389651 DOI 10.17182/hepdata.29449

The ration R = σ(e + = p)/σ(e − + p) of the elastic scattering cross section of positrons and electrons on protons was measured at momentum transfers of 11.66 fm −2 and 35.1 fm −2 . The results are consistent with R = 1.

1 data table

No description provided.


The Charge Form Factor of the Proton at a Momentum Transfer of 75 F$^-^2$

Bartel, W. ; Dudelzak, B. ; Krehbiel, H. ; et al.
Phys.Lett.B 25 (1967) 236-237, 1967.
Inspire Record 1333753 DOI 10.17182/hepdata.29448

The proton form factors GE(q2) and GM(q2) are determined at q2 = 75fm−2.

2 data tables

No description provided.

No description provided.


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

Polarized beam.


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

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


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

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.


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

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.


Measurements of the Deuteron and Proton Magnetic Form-factors at Large Momentum Transfers

Bosted, Peter E. ; Katramatou, A.T. ; Arnold, R.G. ; et al.
Phys.Rev.C 42 (1990) 38-64, 1990.
Inspire Record 283632 DOI 10.17182/hepdata.26165

Measurements of the deuteron elastic magnetic structure function B(Q2) are reported at squared four-momentum transfer values 1.20≤Q2≤2.77 (GeV/c)2. Also reported are values for the proton magnetic form factor GMp(Q2) at 11 Q2 values between 0.49 and 1.75 (GeV/c)2. The data were obtained using an electron beam of 0.5 to 1.3 GeV. Electrons backscattered near 180° were detected in coincidence with deuterons or protons recoiling near 0° in a large solid-angle double-arm spectrometer system. The data for B(Q2) are found to decrease rapidly from Q2=1.2 to 2 (GeV/c)2, and then rise to a secondary maximum around Q2=2.5 (GeV/c)2. Reasonable agreement is found with several different models, including those in the relativistic impulse approximation, nonrelativistic calculations that include meson-exchange currents, isobar configurations, and six-quark configurations, and one calculation based on the Skyrme model. All calculations are very sensitive to the choice of deuteron wave function and nucleon form factor parametrization. The data for GMp(Q2) are in good agreement with the empirical dipole fit.

2 data tables

The measured cross section have been devided by those obtained using the dipole form for the proton form factors: G_E=1/(1+Q2/0.71)**2, G_E(Q2)=G_M(Q2)/mu,where Q2 in GeV2, mu=2.79.

Axis error includes +- 0.0/0.0 contribution (?////Errors given are the statistical errors and systematic uncertainties add ed in quadreture).


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

No description provided.

No description provided.

No description provided.

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Electromagnetic form-factors of the proton at squared four momentum transfers between 10-fm**-2 and 50 fm**-2

Berger, C ; Burkert, V. ; Knop, G. ; et al.
Phys.Lett.B 35 (1971) 87-89, 1971.
Inspire Record 69362 DOI 10.17182/hepdata.28478

Electron-proton elastic scattering cross sections have been measured to determine the proton electromagnetic form factors at squared four-momentum transfers q 2 between 10 and 50 fm −2 . At these values of q 2 we measured angular distributions between 25° and 110° and in addition at 25° and 35° cross sections for q 2 from 2 to 20 fm −2 using the external electron beam of the Bonn 2.5 GeV electron synchrotron. Our results confirm deviations from the scaling law.

15 data tables

Axis error includes +- 2/2 contribution (NORMALIZATION ERROR).

Axis error includes +- 2/2 contribution (NORMALIZATION ERROR).

Axis error includes +- 2/2 contribution (NORMALIZATION ERROR).

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