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Measurements were performed for the photodisintegration cross section of the deuteron for photon energies from 1.6 to 2.8 GeV and center-of-mass angles from 37° to 90°. The measured energy dependence of the cross section at θ_(c.m.)=90° is in agreement with the constituent counting rules.

Cross sections are presented for the reaction 2H(e,e′p)n for momentum transfers in the range 1.2≤Q^2≤6.8 (GeV/c)^2 and for missing momenta from 0 to 250 MeV/c. The longitudinal-transverse interference structure function has been separated at Q^2 = 1.2 (GeV/c)^2. The observables are compared to calculations performed in nonrelativistic and relativistic frameworks. The data are best described by a fully relativistic calculation.

Cross sections for deep-inelastic electron scattering from liquid deuterium, gaseous $^{4}\mathrm{He}$, and solid Be, C, Al, Ca, Fe, Ag, and Au targets were measured at the Stanford Linear Accelerator Center using electrons with energies ranging from 8 to 24.5 GeV. These data cover a range in the Bjorken variable $x$ from 0.089 to 0.8, and in momentum transfer ${Q}^{2}$ from 2 to 15 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. The ratios of cross sections per nucleon ${(\frac{{\ensuremath{\sigma}}^{A}}{{\ensuremath{\sigma}}^{d}})}_{\mathrm{is}}$ for isoscalar nuclei have been extracted from the data. These ratios are greater than unity in the range $0.1lxl0.3$, while for $0.3lxl0.8$ they are less than unity and decrease logarithmically with atomic weight $A$, or linearly with average nuclear density. No ${Q}^{2}$ dependence in the ratios was observed over the kinematic range of the data. These results are compared to various theoretical predictions.

Cross sections for threshold electron scattering from the proton have been measured in the missing mass squared region [ital M][sup 2][lt][ital W][sup 2][lt]2 (GeV)[sup 2] and the four-momentum transfer squared region 6[lt][ital Q][sup 2][lt]30 (GeV/[ital c])[sup 2]. Scaling of the extracted values of the structure function [ital F][sub 2]=[nu][ital W][sub 2] is examined in the variables [ital x], [xi], and [ital W][sup 2]. The best scaling is found for the quantity [ital Q][sup 6][ital F][sub 2], which is found to be linearly proportional to ([ital W][sup 2][minus][ital W][sub th][sup 2]), where [ital W][sub th]=[ital M]+[ital M][sub [pi]].

Measurements of the forward-angle differential cross section for elastic electron-proton scattering were made in the range of momentum transfer from [ital Q][sup 2]=2.9 to 31.3 (GeV/[ital c])[sup 2] using an electron beam at the Stanford Linear Accelerator Center. The data span six orders of magnitude in cross section. Combinded statistical and systematic uncertainties in the cross section measurements ranged from 3.6% at low [ital Q][sup 2] to 19% at high [ital Q][sup 2]. These data have been used to extract the proton magnetic form factor [ital G][sub [ital M]][sup [ital p]]([ital Q][sup 2]) and Dirac form factor [ital F][sub 1][sup [ital p]]([ital Q][sup 2]) by using form factor scaling. The logarithmic falloff of [ital Q][sup 4][ital F][sub 1][sup [ital p]] expected from leading twist predictions of perturbative quantum chromodynamics is consistent with the new data at high [ital Q][sup 2]. Some nonperturbative and hybrid calculations also agree with our results.

Deuteron electrodisintegration cross sections near 180\ifmmode^\circ\else\textdegree\fi{} have been measured near breakup threshold for the four-momentum transfer squared ${\mathit{Q}}^{2}$ range 1.21--2.76 (GeV/c${)}^{2}$. Evidence for a change of slope in the cross section near ${\mathit{Q}}^{2}$=1 (GeV/c${)}^{2}$ has been obtained. The data are compared to nonrelativistic calculations, which predict a strong influence of meson-exchange currents. The data are also compared to a hybrid quark-hadron model. None of these calculations agrees with the data over the entire measured range of ${\mathit{Q}}^{2}$. The ratio of inelastic structure functions ${\mathit{W}}_{1}$(${\mathit{Q}}^{2}$,${\mathit{E}}_{\mathit{n}\mathit{p}}$)/${\mathit{W}}_{2}$(${\mathit{Q}}^{2}$,${\mathit{E}}_{\mathit{n}\mathit{p}}$) is extracted from the present results and previous forward angle data. No prediction is in good agreement with the deduced ratios at small relative energy ${\mathit{E}}_{\mathit{n}\mathit{p}}$.

Measurements of the deuteron elastic magnetic structure function B(${\mathit{Q}}^{2}$) are reported at squared four-momentum transfer values 1.20\ensuremath{\le}${\mathit{Q}}^{2}$\ensuremath{\le}2.77 (GeV/c${)}^{2}$. Also reported are values for the proton magnetic form factor ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$) at 11 ${\mathit{Q}}^{2}$ 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\ifmmode^\circ\else\textdegree\fi{} were detected in coincidence with deuterons or protons recoiling near 0\ifmmode^\circ\else\textdegree\fi{} in a large solid-angle double-arm spectrometer system. The data for B(${\mathit{Q}}^{2}$) are found to decrease rapidly from ${\mathit{Q}}^{2}$=1.2 to 2 (GeV/c${)}^{2}$, and then rise to a secondary maximum around ${\mathit{Q}}^{2}$=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 ${\mathit{G}}_{\mathit{M}\mathit{p}}$(${\mathit{Q}}^{2}$) are in good agreement with the empirical dipole fit.

The deep-inelastic electron-scattering cross sections per nucleon ${\ensuremath{\sigma}}_{A}$ for D, He, Be, C, A1, Ca, Fe, Ag, and Au were measured in the kinematic range $0.09l~xl~0.9$ and $2l~{Q}^{2}l~15$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ with use of electrons with energies ranging from 8 to 24.5 GeV. The ratio $\frac{{\ensuremath{\sigma}}_{A}}{{\ensuremath{\sigma}}_{\mathrm{D}}}$ is consistent with unity in the range $0.1lxl0.3$. For $0.3lxl0.8$, the ratio decreases logarithmically with atomic weight $A$, or linearly with average nuclear density. No ${Q}^{2}$ dependence in the ratio was observed over the kinematic range of the data.

The design and operation of a double-arm 180° spectrometer system for elastic and inelastic electron scattering from deuterium is described. The system consisted of a chicane of dipole magnets to transport an incident electron beam to a target, an upstream QQQDD spectrometer with a bend angle of 65° to analyze backscattered electrons, a downstream QQQDDDD spectrometer with a bend angle of 66° to detect recoil particles produced at 0°, and a movable beam dump. The large acceptance of the system allowed measurements of the deuteron magnetic elastic B(Q2) and inelastic W1(v, Q2) structure functions at high momentum transfers. The performance is compared to the predictions of a Monte Carlo simulation program.

The deuteron magnetic form factor B(${Q}^{2}$) has been measured at momentum transfers ${Q}^{2}$=1.21, 1.49, 1.61, 1.74, 1.98, 2.23, 2.48, 2.53, and 2.77 (GeV/c${)}^{2}$ at the Stanford Linear Accelerator Center by detection of electrons backscattered at 180\ifmmode^\circ\else\textdegree\fi{} in coincidence with recoiling deuterons at 0\ifmmode^\circ\else\textdegree\fi{}. The data for B(${Q}^{2}$) are found to decrease rapidly from ${Q}^{2}$=1.2 to 2 (GeV/c${)}^{2}$, then rise to a secondary maximum around ${Q}^{2}$=2.5 (GeV/c${)}^{2}$, in qualitative agreement with impulse-approximation calculations.

Cross sections for 180\ifmmode^\circ\else\textdegree\fi{} inelastic electron scattering from deuterium were measured from breakup threshold to beyond the quasielastic peak for incident-beam energies of 0.843, 1.020, 1.189, and 1.281 GeV, corresponding to $0.75\ensuremath{\le}{Q}^{2}\ensuremath{\le}2.57$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. The data are in reasonable agreement with nonrelativistic models that include final-state interactions and meson-exchange currents. The scaling function $F(y)$ for these data is generally in agreement with $F(y)$ for forward-angle data at the same ${Q}^{2}$. Values of ${G}_{M}^{n}$ determined from the data are in good agreement with results from previous experiments.

The deep inelastic electron scattering cross sections per nucleon sigma/sub A/ for d, He, Be, C, Al, Ca, Fe, Ag, and Au were measured in the kinematic range 0.09 less than or equal to x less than or equal to 0.9 and 2 less than or equal to Q/sup 2/ less than or equal to 15 (GEV/c)/sup 2/ using electrons with energies ranging from 8 to 24.5 GeV. The ratio sigma/sub A//sigma/sub d/ is consistent with unity in the range 0.1 < x < 0.3. For 0.3 < x < 0.8, the ratio decreases logarithmically with atomic weight A, or linearly with average nuclear density. No Q/sup 2/ dependence in the ratio was observed over the kinematic range of the data. 12 references.

Cross sections for 180° inelastic electron scattering from the deuteron were measured from the break‐up threshold to beyond the quasielastic peak for incident beam energies between 0.7 and 1.3 GeV, corresponding to 0.75≤Q2≤2.75 (GeV/c)2. The data are in reasonable agreement with nonrelativistic models that include final‐state interactions are meson exchange currents.

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, Comment: 5 pages, 3 figures To be published in Phys. Rev. Lett