Model three-body calculations have been performed with two-channel separable interactions to test the predictions for angular distributions and spectroscopic factors by Butler, Hewitt, McKellar, and May, and distorted-wave-approximation theories of deuteron stripping. There are indications that both theories are inadequate.

Quartet states in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ are preferentially populated in the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}({}_{}{}^{12}{}_{}{}^{}\mathrm{C},\alpha ){}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=5.7,6.0, \mathrm{and} 6.3$ MeV. This may be due to $\alpha$-particle doorway states having a large overlap with quartet states in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. The interpretation of the correlated resonances in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ system as intermediate structure resulting from $\alpha$-particle doorway states is supported by the results of the measurement reported.

The ambiguity in the sign of the hexadecapole moments of ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$, as determined from $\alpha$-particle Coulomb-excitation experiments, has been resolved by experiments using 145-MeV ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ to multiply Coulomb excite these nuclei up to their ${12}^{+}$ states. Excellent agreement with the experimental results was obtained with predictions from the Winther—de Boer program when positive $M\left(E4\mathrm{}\right)\mathrm{}$ values were used, while significant disagreement was found when the negative $M\left(E4\mathrm{}\right)\mathrm{}$ values were used.

Elastic and inelastic scattering of 50-MeV helium ions from ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ was studied with a high-resolution magnetic spectrometer. We measured angular distributions for members of the ground-state rotational band up to the $8^{+}$ level. Coupled-channels calculations yield 0.022, 0.060, and -0.012 for the respective deformation parameters ${\beta }_2$, ${\beta }_4$, and ${\beta }_6$ for an optical radius of $1.44A^{\frac{1}{3}}$ fm. These values are compared with other experimental results.

A bubble-chamber study of proton-proton interactions at 205 GeV yielded 66 $K^0$'s, 28 $\Lambda$'s, and 2 $\Lambda$'s produced in the backward c.m. hemisphere. The cross sections for $p+p\to \left(\frac{\Lambda }{{\Sigma }^0}\right)$ + anything and $p+p\to \left(\frac{K^0}{{\overline{K}}^0}\right)$ + anything are 3.2±0.6 and 12.9±1.7 mb, respectively. Comparison of the invariant cross section with lower-energy data shows that ($\frac{\Lambda }{{\Sigma }^0}$) production is consistent with approximate scaling behavior above 28 GeV, whereas the ($\frac{K^0}{{\overline{K}}^0}$) invariant cross section has increased considerably between 28 and 205 GeV.

Low-energy structure in the total He $2^{3}S-\mathrm{Ne} 4s^{\prime }\left[\frac{1}{2}\right]_1^{}{}_{}{}^0$, $4s^{\prime }\left[\frac{1}{2}\right]_0^{}{}_{}{}^0$ transfer cross section has been extracted from temperature-dependent pulsed-afterglow measurements. The results confirm the existence of a nonobligatory potential barrier in an exothermic atomatom transfer collision.

The yield and high-energy limit (from 1.1 to 1.5 keV) of a $K$ x-ray band emitted by the transient C-C collision system are reported for 19- to 240-keV carbon ions incident on graphite. This $K$ x-ray band is interpreted as characteristic of the C-C system when the nuclear separation approaches the united-atom limit. A small yield of a similar band produced by other light ions in graphite has been observed; this can be accounted for in part by integrating the C-C yield over the appropriate energy distribution of recoil carbon atoms.

Momentum distributions have been measured separately for $3p$ and $3s$ electrons in argon. The measured summed energy spectrum shows the presence of a peak which is analyzed in terms of electron-electron correlations.

We present in support of Andreev's model a fully microscopic calculation of the surface states of ${\mathrm{He}}^3$ in dilute ${\mathrm{He}}^3$-${\mathrm{He}}^4$ solutions. The surface structure of pure ${\mathrm{He}}^4$ is first determined. We find a surface tension of 0.36 dyn/cm, in good agreement with experiment. For ${\mathrm{He}}^3$ there is just one bound surface state, at an energy 1.6°K lower than the chemical potential of ${\mathrm{He}}^3$ in bulk solutions, centered on the Gibbs surface of the liquid.

Coherent scattering of neutrons by liquid parahydrogen shows the existence of well-defined collective excitations in this liquid. Qualitative similarity with the scattering from liquid helium is found. Furthermore, in the range of observed wave vectors, 0.7 ${\mathrm{\AA }}^{-1\mathrm{}}<~\kappa <~3.1{\mathrm{\AA }}^{-1\mathrm{}}$, extending from the first through the third Brillouin zones in the solid, $S(\kappa ,\omega )$ is remarkably similar to the scattering law expected from a polycrystal. For $\kappa <~2.3$ ${\mathrm{\AA }}^{-1\mathrm{}}$ the observed spectra satisfy the one-phonon sum rule with mean square displacement $〈u^2〉=1.0\mathrm{}$ ${\mathrm{\AA }}^2$.

We have determined the accommodation coefficient $\gamma$ of a helium film from 1.15 to 4°K by measuring the time constant of a rotating superconducting Nb sphere levitated in vapor and covered with a saturated helium film. The conventianal assumption of the phenomenological theory of superfluidity, that the order parameter $\psi$ vanishes at the free surface of helium II, implies that $\gamma$ is unity and independent of temperature. We find that $\gamma$ is nearly unity above the $\lambda$ point, suffers an abrupt drop close to $T_{\lambda }$, and gradually levels off to the value of $\simeq$ 0.8 at lower temperatures.

Recombination cross sections for electrons at ionized, group-V donors in silicon have been measured between 1.5 and 20 K. The results are in good agreement with the theoretically predicted temperature dependence above 4 K, although the magnitude of the experimental cross section is larger by more than 2 orders of magnitude.

Antiresonances (sharp attenuation minima) have been observed in copper for shear acoustic waves propagating along [111] and for magnetic fields along [$11\overline{2}$] satisfying the resonance condition for open orbits along [$1\overline{1}0$]. The antiresonances give way to conventional resonances when the polarization vector $\overrightarrow{\epsilon }$ deviates from [$11\overline{2}$] by more than about 30°. We believe that the antiresonances are due to the so-called field force on the conduction electrons, whereas the resonances are due to the deformation force.

Recoil-distance decay curves for ground-band transitions in ${}_{}{}^{158}{}_{}{}^{}\mathrm{Er}$ were measured using a $\gamma -\gamma$ coincidence technique and the reaction ${}_{}{}^{130}{}_{}{}^{}\mathrm{Te}({}_{}{}^{32}{}_{}{}^{}\mathrm{S},4n){}_{}{}^{158}{}_{}{}^{}\mathrm{Er}$. We find that the mean lifetimes for the ${14}^{+}$, ${16}^{+}$, and ${18}^{+}$ levels are, respectively, 3.0 ± 0.7, 2.5 ± 0.9, and < 2.2 psec. These results are consistent with the rotational model in spite of the severe "backbending" of the level spacings.

States of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Po}$ up to an excitation energy of 2 MeV have been investigated via the two-neutron pickup reaction ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}\mathrm{}(p,t)\mathrm{}{}_{}{}^{208}{}_{}{}^{}\mathrm{Po}$. We have extracted angular distributions for the five observed states of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Po}$ and have made $J^{\pi }$ assignments. These states are discussed in terms of the excitation of simple modes observed in ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ and ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$. Matrix elements have been extracted for the interaction between the two-neutron-hole $2^{+}$ excitations and the two-proton-particle $2^{+}$ excitations and compared with simple theoretical estimates.

A careful search has been made for possible $\mathrm{CP}$-nonconserving differences between $K^{+}\to {\pi }^{+}{\pi }^0\gamma$ and $K^{-}\to {\pi }^{-}{\pi }^0\gamma$ decays. In a sample of over 4000 completely reconstructed decays in the charged-pion kinetic-energy interval of 51 to 100 MeV, the asymmetry is 0.005 ± 0.020, with a systematic uncertainty of ± 0.022, indicating no evidence for a $\mathrm{CP}$-invariance violation. This result, combined with that obtained from the sum spectrum, suggests that the direct emission is largely magnetic dipole.

The reaction ${\pi }^{-}p\to \eta {\pi }^{-}p$ at 6.0 $\frac{\mathrm{GeV}}{c}$ has been studied at the Argonne zero-gradient synchrotron using optical spark chambers. About 1400 events have been obtained in the range $0.80<\mathrm{}{M}_{\eta \pi }<1.55\mathrm{} \frac{\mathrm{GeV}}{c^2}$, yielding approximately 1000 events of the type $A_2^{}{}_{}{}^{-}\to \eta {\pi }^{-}$, with $0.27<\mathrm{}\left|t\right|<0.42\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2$. No structure is discernible within the $A_2$ mass spectrum with an experimental resolution of 7.1 $\frac{\mathrm{MeV}}{c^2}$ [full width at half-maximum $\left(\mathrm{FWHM}\right)=16.7\mathrm{} \frac{\mathrm{MeV}}{c^2}$]. A single $D$-wave Breit-Wigner distribution fits the data with a high confidence level yielding the parameters $M_0=1.323\mathrm{}\pm 0.003 \frac{\mathrm{GeV}}{c^2}$ and ${\Gamma }_0=0.108\mathrm{}\pm 0.009 \frac{\mathrm{GeV}}{c^2}$ for the $A_2$.

We have measured the cross section for electron-positron elastic scattering at 4 GeV center-of-mass energy for scattering angles between 50° and 130°. We have calculated the theoretical (quantum-electrodynamics) cross section including a radiative correction calculated using the peaking approximation. The ratio of the experimental and theoretical cross sections is 0.88 ± 0.10. We therefore obtain new bounds on the quantum-electrodynamics breakdown parameters, ${\Lambda }_{+}>12\mathrm{}$ GeV and ${\Lambda }_{-}>6\mathrm{}$ GeV.

We observed broad bumps at 2193 and 2359 MeV in the elastic, inelastic, and annihilation $\overline{p}p$ cross sections. We find that the positions and widths of the structures are invariant to changes in the multiplicity and degree of nonperipheralism. Multiplicity distributions indicate that the structure at 2193 has no contribution from single $\pi$ production, while as much as 40% of the structure at 2359 could be due to this process.

We calculate the baryon mass differences in a model of strong and electromagnetic interactions based on a spontaneously broken U(3) $\otimes$ U(1) gauge invariance. Good agreement with experimental values is obtained.