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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.

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Inclusive electron scattering from nuclei at x approximately = 1

Arrington, J. ; Anthony, P. ; Arnold, R.G. ; et al.

Phys.Rev.C 53 (1996) 2248-2251, 1996.

Inspire Record 394586 DOI 10.17182/hepdata.25857

The inclusive A(e,e') cross section for $x \simeq 1$ was measured on $~2$H, C, Fe, and Au for momentum transfers $Q~2$ from 1-7 (GeV/c)$~2$. The scaling behavior of the data was examined in the region of transition from y-scaling to x-scaling. Throughout this transitional region, the data exhibit $\xi$-scaling, reminiscent of the Bloom-Gilman duality seen in free nucleon scattering.

3 data tables match query

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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.

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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.

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

Measurement of the Proton Elastic Form-factors for $Q^2=1$-{GeV}/$c^2$ - 3-{GeV}/$c^2$

Walker, R.C. ; Filippone, B.W. ; Jourdan, J. ; et al.

Phys.Lett.B 224 (1989) 353-353, 1989.

Inspire Record 284687 DOI 10.17182/hepdata.29803

We report measurements of the proton elastic form factors, G E p and G M p , extracted from electron scattering in the range 1⩽ Q 2 ⩽3(GeV/ c ) 2 . The uncertainties are <15% in G E p and <3% in G M p . The values of G E p are larger than indicated by most theoretical parameterizations, The ratio of Pauli and Dirac form factors, Q 2 F 2 p / F 1 p , is lower and demonstrates less Q 2 dependence than most of these parameterizations. Comparisons are made to theoretical models, including those based on perturbative QCD and vector-meson dominance.

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Two-body disintegration of the deuteron with 0.8-GeV to 1.8-GeV photons

Freedman, S.J. ; Geesaman, D.F. ; Gilman, Ronald A. ; et al.

Phys.Rev.C 48 (1993) 1864-1878, 1993.

Inspire Record 365233 DOI 10.17182/hepdata.26023

The differential cross section for the reaction H2(γ,p)n has been measured at several center-of-mass angles ranging from 50° to 143° for photon energies between 0.8 and 1.8 GeV. The experiment was performed at the SLAC-NPAS facility with the use of the 1.6 GeV/c spectrometer to detect the high energy protons produced by a bremsstrahlung beam directed at a liquid deuterium target. Contributions from concurrent disintegration by the residual electron beam were determined by measuring the proton yield without the Cu photon radiator. At angles not very far from 90°, the energy dependence of the cross sections is consistent with predictions of scaling using counting rules for constituent quarks. At least one theoretical calculation based on a meson-baryon picture of the reaction is able to reproduce the magnitude and energy dependence of the 90° cross section. The angular distribution exhibits a large enhancement at backward angles at the higher energies.

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Table 1

THE QUOTED ERRORS ARE STATISTICAL ONLY.

Electroproduction of the Delta Resonance at High Momentum Transfer

Frolov, V.V. ; Adams, G.S. ; Ahmidouch, A. ; et al.

Phys.Rev.Lett. 82 (1999) 45-48, 1999.

Inspire Record 475116 DOI 10.17182/hepdata.41616

We studied the electroproduction of the Delta(1232) resonance via the reaction p(e,e'p)\pi0 at four-momentum transfers Qsq = 2.8 and 4.0 GeV^2. This is the highest Qsq for which exclusive resonance electroproduction has ever been observed. Decay angular distributions for Delta to p-pi0$ were measured over a wide range of barycentric energies covering the resonance. The $N-\Delta$ transition form factor G*_M and ratios of resonant multipoles E{1+}/M{1+} and S{1+}/M{1+} were extracted from the decay angular distributions. These ratios remain small, indicating that perturbative QCD is not applicable for this reaction at these momentum transfers.

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CONST(NAME=E1+/M1+) and CONST(NAME=S1+/M1+) are the ratios of the electric quadrupole moment to magnetic dipole moment and Coulomb quadrupole moment to magnetic dipole moment, respectively (see paper). Resonance only.

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CONST(NAME=E1+/M1+) and CONST(NAME=S1+/M1+) are the ratios of the electric quadrupole moment to magnetic dipole moment and Coulomb quadrupole moment to ma gnetic dipole moment, respectively (see paper). Resonance + background.

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Precision determination of the neutron spin structure function g1(n).

The E154 collaboration Abe, K. ; Akagi, T. ; Anderson, B.D. ; et al.

Phys.Rev.Lett. 79 (1997) 26-30, 1997.

Inspire Record 443170 DOI 10.17182/hepdata.19559

We report on a precision measurement of the neutron spin structure function $g^n_1$ using deep inelastic scattering of polarized electrons by polarized ^3He. For the kinematic range 0.014<x<0.7 and 1 (GeV/c)^2< Q^2< 17 (GeV/c)^2, we obtain $\int^{0.7}_{0.014} g^n_1(x)dx = -0.036 \pm 0.004 (stat) \pm 0.005 (syst)$ at an average $Q^2=5 (GeV/c)^2$. We find relatively large negative values for $g^n_1$ at low $x$. The results call into question the usual Regge theory method for extrapolating to x=0 to find the full neutron integral $\int^1_0 g^n_1(x)dx$, needed for testing quark-parton model and QCD sum rules.

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Determination of the neutron spin structure function..

The E142 collaboration Anthony, P.L. ; Arnold, R.G. ; Band, H.R. ; et al.

Phys.Rev.Lett. 71 (1993) 959-962, 1993.

Inspire Record 359353 DOI 10.17182/hepdata.19693

The spin structure function of the neutron g1n has been determined over the range 0.03

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Extrapolarity to full x range.

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Precision measurement of R = sigma-L / sigma-T on hydrogen, deuterium and beryllium targets in deep inelastic electron scattering

A COMBINED ANALYSIS OF SLAC EXPERIMENTS ON DEEP INELASTIC e p AND e d SCATTERING

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

Inclusive electron scattering from nuclei at x approximately = 1

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

Measurement of the Proton Elastic Form-factors for $Q^2=1$-{GeV}/$c^2$ - 3-{GeV}/$c^2$

Two-body disintegration of the deuteron with 0.8-GeV to 1.8-GeV photons

Electroproduction of the Delta Resonance at High Momentum Transfer

Precision determination of the neutron spin structure function g1(n).

Determination of the neutron spin structure function..