We find that the double differential cross section for $\mathrm{pp}$ inelastic collisions at high energy can be well reproduced over a range of two decades by a simple version of the multi-Regge model, in which baryon exchange is responsible for large momentum transfers to the final proton. The model is an asymptotic one, and we show predictions at 70 and 200 GeV/c.

A phenomenological discussion is given, together with an estimate of the magnitude, of the possibly quite large $\mathrm{CP}$-noninvariant effects which may be present in $K^{\pm }\to {\pi }^{\pm }{\pi }^{+}{\pi }^{-}\gamma$ decays.

A new type of continuous-moment sum rule is proposed. It retains the flexibility of the the usual continuous-moment sum rule but avoids Re$F$ in the low-energy integration. Also, it exploits the low- and intermediate-energy data more efficiently than was possible previously. We apply it to the forward pion-nucleon charge-exchange scattering to obtain ${\alpha }_{\rho }=0.659\mathrm{}\pm 0.02$ and ${\gamma }_{\rho }=0.0173\mathrm{}\pm 0.001$.

A theory of interaction among the longitudinal modes in a laser made of highly dispersive material is outlined and used to interpret a spontaneous pulsing of the laser intensity at a frequency two orders of magnitude lower than the mode separation, shown to occur in GaAs lasers. Power coupling among the modes in the presence of spontaneous or forced microwave modulation of the population inversion is also explained.

Measurements of the optical properties of pure liquid benzene in the vacuum ultraviolet are interpreted in terms of a molecular excitation of the $\pi$ electrons and also collective, volume-plasma oscillations of these same electrons.

It is shown that the bootstraplike equation of Migdal's recent theory of phase transitions has a spurious solution if truncated improperly and must be handled with caution if physically sensible solutions are to be obtained.

We report experimental observation of resonance cones in the angular distribution of the radio-frequency electric field of a short antenna in a plasma in a static magnetic field. The cone angle is observed to vary with incident frequency, cyclotron frequency, and plasma frequency in agreement with simple plasma dielectric theory. We discuss the relationship of these cones to the limiting phase- and group-velocity cones which appear in the theory of plane wave propagation.

A magnetohydrodynamically stable, toroidal, dynamic equilibrium for a high-$\beta$ plasma can be obtained by superimposing an oscillating bumpy magnetic field upon a purely toroidal static main field.

The role of primary spherical aberration caused by simple lenses used in studies of laser-induced breakdown of gases has been investigated theoretically. The results obtained lead to an explanation of the observed multiplicity of distinct collinear regions of intense ionization along the optic axis near the lens focus. The values of separation between distinct plasmas and their apparent propagation velocity towards the lens calculated from the analysis are in good agreement with measured values.

A new method for calculating the resistance of superfluids is proposed. The method is applied to derive the temperature-dependent thickness of ${\mathrm{He}}^4$ films at which superflow ceases. The agreement with the experimental results is good.

We have made spin-spin ($T_2$) and spin-lattice ($T_1$) relaxation measurements of ${}_{}{}^{35}{}_{}{}^{}\mathrm{Cl}$ in Pr${\mathrm{Cl}}_3$ from 4.2 to 0.08 K. $T_1$ and $T_2$ show unusual temperature dependences in both the paramagnetic and antiferromagnetic states.

We show qualitatively how the Fermi surface of a disordered alloy will be reflected in the local-order diffuse scattering of x rays, etc., through anomalies similar to those predicted by Kohn for phonon scattering. These ideas are then applied to the existing data on the splitting of the diffuse spots from Cu-Au alloys above $T_c$ and, more tentatively, to the <111> scattering profile from $\beta -\mathrm{CuZn}$. The results indicate that disordered ${\mathrm{Cu}}_3$Au has a Fermi surface much like copper's while disordered Cu${\mathrm{Au}}_3$ resembles gold.

A theory is presented which, in conjunction with previous theories, explains for the first time all notable experimental results on exchange and magnetostatic modes in thin films, including surface and bulk modes. Roughly speaking, a surface inhomogeneity thinner than $\sim {\left(\frac{1}{2}\Lambda \right)}^{\frac{1}{2}}$ gives little pinning, while one thicker than $\sim {\left(\frac{1}{2}\Lambda \right)}^{\frac{1}{2}}$ pins the low-order modes. The results, obtained by considering the change of $M_z$ in the surface region, reconcile the different boundary conditions used for thin-film exchange modes and for magnetostatic modes.

A core-particle coupling-model calculation of the negative-parity levels in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ using random-phase-approximation states succeeds in explaining the strong fragmentation of the octupole strength in this nucleus relative to ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$. The calculation also succeeds in producing the high density of odd-parity levels and their spectral positions but fails badly to account for the spectroscopic factors in the reaction ${}_{}{}^{42}{}_{}{}^{}\mathrm{K}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$.

Characteristics of the level structure of $N=82\mathrm{}$ nuclei are studied with a shell model.

Finite nuclear potentials are compared with the conventional harmonic-oscillator potential in studying the diffraction minima in elastic electron scattering from ${\mathrm{O}}^{16}$ and ${\mathrm{C}}^{12}$. The effects of admixtures of two-particle, two-hole configurations in the ground states on the form factors are considered.

The (${}_{}{}^3{}_{}{}^{}\mathrm{He},p$) reactions on ${}_{}{}^{46}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$, and ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$ leading to the $0^{+}$ analog states were studied and compared with the ($t,p$) reactions on the same target nuclei and with the predictions of the pairing vibration model.

We have measured total reaction cross sections for 60-MeV protons on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$, ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$, ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. We find that, contrary to previous measurements, our results agree with predictions of the optical model. For a fixed-geometry potential the volume absorption term is reasonably constant with $A$, while the surface absorption term increases monotonically from 0.12 MeV for Al to 4.2 MeV for Pb.

Cross sections for the reactions $\gamma p\to K^{+}\Lambda$ and $\gamma p\to K^{+}{\Sigma }^0$ have been measured at squared four-momentum transfer ($-t$) from 0.005 to 2 ${\mathrm{GeV}}^2$, at photon energies 5, 8, 11, and 16 GeV. For $-t>\mathrm{}0.2\mathrm{}$ ${\mathrm{GeV}}^2$ each of the $K^{+}$ cross sections is about ⅓ of the ${\pi }^{+}n$ photoproduction cross section, having nearly the same energy and momentum-transfer dependence. The $K^{+}$ cross sections fall off at small $\mathrm{}\left|t\right|\mathrm{}$, however, in contrast to the sharp forward spike seen in ${\pi }^{+}n$; this leads to a disagreement with an SU(3) prediction for $-t<\mathrm{}0.1\mathrm{}$ ${\mathrm{GeV}}^2$. The ratio of $K^{+}{\Sigma }^0$ to $K^{+}\Lambda$ cross sections is typically between 0.5 and 1.0.

The photoproduction of wide-angle muon pairs from carbon has been measured in order to test the validity of quantum electrodynamics at small distances. The data extend to a muon-pair invariant mass of about 1150 MeV and is consistent with quantum electrodynamics.