On the basis of a parton model studied earlier we consider the production process of large-mass lepton pairs from hadron-hadron inelastic collisions in the limiting region, $s\to \infty$, $\frac{Q^2}{s}$ finite, $Q^2$ and $s$ being the squared invariant masses of the lepton pair and the two initial hadrons, respectively. General scaling properties and connections with deep inelastic electron scattering are discussed. In particular, a rapidly decreasing cross section as $\frac{Q^2}{s}\to 1$ is predicted as a consequence of the observed rapid falloff of the inelastic scattering structure function $\nu W_2$ near threshold.

A general unitary phenomenological description of strongly interacting three-particle systems is developed in terms of two-particle phase shifts and binding energies, two-particle wave functions inside the range of forces, and the three-body wave function in the region where all three force ranges overlap. The two-particle external and internal parameters are unambiguously separated from each other and the same parameters can be determined from many different experiments, while the three-body parameters refer to a specific system at a specific energy.

The 79-μm electric dipole spectrum of OH (${}_{}{}^2{}_{}{}^{}\Pi _{\frac{3}{2}}^{}{}_{}{}^{},J=\frac{3}{2}\leftrightarrow {}_{}{}^2{}_{}{}^{}\Pi _{\frac{1}{2}}^{}{}_{}{}^{},J=\frac{1}{2}$) has been measured by a magnetic-resonance absorption method, with a water-vapor laser as the source oscillator. Corresponding magnetic dipole spectra are calculated from the data. A near overlap of the water line on one magnetic-dipole transition suggests a possible pumping mechanism for the 18-cm maser emission of stellar OH.

It is suggested that intense laser fields may be used to modulate the wave functions of electrons. A classical model is used to demonstrate the greatly altered radiation fields of these electrons after they emerge from the laser beam. The observation by Schwarz and Hora of visible radiation from a nonluminescent target appears to result from these fields.

The linked-cluster many-body perturbation theory is developed for molecules using the united atom as a starting point. Specific application is made to hydrogen fluoride with neon as the united atom. The calculated energy for the molecule is found to be -100.4186 a.u. in excellent agreement with the experimental value of -100.4485 a.u. The theoretical correlation energy is found to be 92% of experiment. Satisfactory agreement is also obtained for the electric field at the fluorine nucleus.

We have performed measurements of the shape of the absorption lines due to transitions from the $2s$ shell in solid Ne and the $3s$ shell in solid Ar. It was found that the asymmetric and the "window" line shapes seen in the absorption spectra of the gases are preserved in the solids.

The theory of Bohr and Lindhard for electron capture and loss by heavy ions penetrating through solids has been modified. It is concluded that the difference in the average equilibrium charge of fast ions traversing solids and dilute gases is mainly due to Auger processes which occur after the ions leave the solid. The charge states inside solids are — in disagreement with the deductions of Bohr and Lindhard — not much larger than those in gases.

We observe a nonlinear dependence of the number of vortex lines in a rotating container on the rotation frequency. The data are consistent with a model in which there are about two missing rows of vortices near the walls.

A "Loschmidt demon" is exhibited which effectively reverses the spin-spin relaxation of a system of interacting magnetic dipoles in a strong external field, thereby demonstrating that this system does not approach internal thermodynamic equilibrium in a time $T_2$ as was implicitly recognized by Philippot.

Recent experiments on the attenuation and velocity of sound in liquid ${\mathrm{He}}^4$ at low temperatures are discussed in terms of the excitation model of liquid ${\mathrm{He}}^4$. By assuming for the long-wavelength excitations the dispersion relation $\epsilon \mathrm{}\left(p\right)=cp[1-\gamma p^2-\delta p^4\cdots ]$ with $\gamma$ negative, we are able to reconcile previous disagreements between theory and experiment.

We present a calculation of the dielectric correlation function in glasses showing how the assumption of short correlation length for normal modes breaks the momentum selection rules and leads to expressions for the first-order Raman-scattering intensity in terms of the density-of-states functions and known frequency-dependent amplitudes.

We report a series of Azbel'-Kaner cyclotron resonance experiments in lead and mercury at wavelengths varying from 9 to 1 mm. We observe that in both metals the electron-phonon relaxation time is frequency dependent ($\tau \propto {\omega }^{-2\mathrm{}}$ in lead), and that the effective mass increases slightly for the highest frequency in mercury (3 ± 1% at $\lambda =1\mathrm{}$ mm).

A study of the Raman scattering near resonance with the exciton transition in pure polar crystals is presented. The following conclusions are obtained, independently of the crystal symmetry: (I) The resonant Raman spectra should show multiphonon structures at energy multiples of the first-order peak. The repetition of the peaks depends on the strength of the exciton-phonon coupling. (II) For the case of large-radius excitons, these spectra should show the same peaks for any polarization of the light.

Magnetically "dead" layers, previously observed in iron films at room temperature, are observed in nickel. From the temperature dependence of this effect it is deduced that two dead layers persist at $T=0\mathrm{}$, independent of the film thickness. Existing theories of magnetic thin films are unable to account for these observations. The existence of dead layers at $T=0\mathrm{}$ is attributed to a transfer of electrons from the $s$ band to the $d$ band in the neighborhood of a surface. This effect is incorporated in Stoner's theory of ferromagnetism and the results on the temperature dependence of the number of dead layers are in good agreement with experiment.

The coupling of the nonactivated spin-flop mode in Mn${\mathrm{F}}_2$ to two elastic modes via the linear magnetoelastic interaction is shown to lead to discontinuities at the spin-flop transition in the elastic constants $c_{11}$ and $c^{\prime }=\frac{1}{2}(c_{11}-c_{12})$. The directions of easy magnetization in the basal plane are determined to be the equivalent [110] axes.

The electrical resistivity of Ni-Cu alloys near the critical composition for ferromagnetism is found to remain anomalous up to temperatures of about 600°K. This behavior is attributed to the existence of giant magnetic polarization clouds and to their ultimate disappearance at these temperatures.

Logarithmic resonances away from the Fermi level are obtained when the magnetic ion of the $s-d$ model is subject to a crystal field. Indications exist that such resonances are observed in the resistivity-versus-temperature curve of Ce${\mathrm{Al}}_3$.

We have used nuclear orientation to measure the internal magnetic field at nuclei of Co in dilute Au(Co) alloys for various values of the applied magnetic field. We find $\frac{H_{\mathrm{internal}}}{H_{\mathrm{applied}}}=1.29\mathrm{}\pm 0.11$ at high fields, indicating a relatively large magnetic moment on the Co.

A theory of the ferromagnetic transmission resonance is presented for the case where the static magnetic field is perpendicular to the sample surface. The theory is compared with experiments performed on ferromagnetic gadolinium and nickel. The agreement between theory and experiment is satisfactory. Since the transmission resonance is a bulk effect it will allow the study of the bulk spin relaxation time and exchange integral as functions of temperature.

Differential scattering data have been obtained in bubble-chamber exposures and are compared with theoretical predictions using the Glauber multiple-scattering theory. The effect of the quadrupole deformation of the deuteron and the influence of the various orders of multiple scattering are put in evidence. Agreement between theoretical predictions and experiment is very good at the higher energy. At the lower energy, agreement is good only for momentum transfers below $0.2 {\left(\frac{\mathrm{GeV}}{c}\right)}^2$. Possible reasons for the disagreement above $0.2 {\left(\frac{\mathrm{GeV}}{c}\right)}^2$ are explored.