A model is proposed for nonleptonic hyperon decays which (1) gives good experimental agreement for both $S$ and $P$ waves, and hence the decay parameters $\alpha$, and (2) requires the $\Delta I=\frac{1}{2}$ rule. The model demands the suppression of certain pole terms. The remaining terms behave like transitions caused by $U$-spin raising or lowering operators acting on $Y=0\mathrm{}$ states.

The ${K_1}^0-{K_2}^0$ mass difference is calculated to lowest order in the intermediate-boson model, using Weinberg's first sum rule. A finite result is obtained without requiring equal coupling of strange and nonstrange mesons to the corresponding currents.

The asymptotic limit of the $\mathrm{pp}$ scattering cross section is considered using a diffraction-scattering model. The calculated differential cross section displays diffraction zeros, which at present energies should be filled in by the real part of the $\mathrm{pp}$ scattering; the $\mathrm{pp}$ polarization should also show considerable structure. It is shown that the high-energy, large-momentum-transfer hadron-hadron scattering amplitude is proportional in this model to a product of hadron form factors.

We suggest that fermion Regge trajectories will be strongly asymmetric functions of $w$ (mass) for $w\lesssim 1$ GeV, in contrast to a recent suggestion of Barger and Cline. This suggestion fits the observed spectrum of $\pi N$ resonances and would also be predicted by conventional low-energy $\pi N$ dynamics.

We propose here a test, using linearly polarized photons, of the hypothesis that the forward peak in charged-pion photoproduction is due to a conspiracy between the pion and an opposite-parity conspirator. The energy dependence of the differential cross section for photons linearly polarized in the plane of scattering can distinguish between a nucleon pole leading to the forward peak or a pion conspirator.

We derive a new relationship between the shape of the critical isotherm and the range of the two-particle correlation function.

The possibility of coupling of low-frequency surface plasmons in tunnel junctions to the ac Josephson current is examined. By comparing theory with experiment, some evidence is obtained for the existence of these surface plasmons in tunnel junctions. Further experiments are suggested to establish the kind of coupling responsible for any particular portion of the $I-V$ characteristic.

A simple model is proposed for the static electronic dielectric constants of zinc-blende and wurtzite crystals in terms of the dielectric constants of diamond-type crystals. The model suggests a natural definition of electronegativity in ($s{p}^3$)-hybridized valence states.

The effect of nuclear orientation on the total neutron cross section of the highly deformed ${}_{}{}^{165}{}_{}{}^{}\mathrm{Ho}$ nucleus has been measured from 2 to 135 MeV. The data are successfully fitted by adiabatic coupled-channel calculations. The origin of this effect can also be understood by a semiempirical model which makes use of both the black-nucleus model and the nuclear Ramsauer effect.

We unitarize the results of soft-pion current-algebra calculations of low-energy parameters for $s$-wave pion-nucleon scattering in the $I=\frac{1}{2}$ channel, using the $\frac{N}{D}$ formalism. We isolate clearly corrections arising from unitarity, off-shell kinematics, and off-shell dynamics.

Maxima and minima recently reported in forward elastic scattering at moderately high energy and large momentum transfer are correlated with exceptional points $\alpha =0, -1, -2, \cdots$ on the $P^{\prime }$ and $\omega$ Regge trajectories. An Ansatz for the Regge residue functions is given that reproduces the qualitative features of the new data. This interpretation leads to further predictions that can be experimentally checked.