The single-particle energies in a nucleus of $A\pm 1$ particles as taken from experiment are seen to be shifted when used for the calculation of the $A$-particle-system excited states. This shift can be described as a change in the particle-hole gap arising from an isospin-isospin interaction of the excited nucleon with the remaining core of $A-1\mathrm{}$ particles. It lowers the $T=0\mathrm{}$ states of ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ by about 1.5 MeV and of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ by 3.75 MeV, and it raises the $T=1\mathrm{}$ states one third this amount. This shift gives an account of discrepancies which are observed in all existing Tamm-Dancoff or random-phase approximation calculations of doubly closed shell nuclei.

In general, an $S$-matrix or phase-shift analysis yields several ambiguous solutions that give identical fits to the data. Computer studies of a simple system involving only a few resonances suggest that the unphysical solutions show characteristic correlations (pseudoresonances) in different partial waves near a true resonance in one partial wave. Therefore, the physical solution requires the fewest resonant states. We apply this criterion to an analysis of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}(d,{\alpha }_1){}_{}{}^{14}{}_{}{}^{}\mathrm{N}$.

A simple approximate procedure for perturbing the self-consistent Hartree-Fock equations in an enlarged single-particle space is given. Using phenomenological interactions and observed single-particle splittings, the second half of the $s-d$ shell is shown to require pear-shaped intrinsic states, involving excitations from the $s-d$ to the $p-f$ shell.

We examine the physical significance of a class of "table-top" experiments proposed by Franken and Ampulski as tests for a finite photon mass $\mu$. Our results stem from a theorem that in the massive-photon case the fields and currents of a system are changed only by order ${\left(\mu D\right)}^2$ from those of the massless-photon case ($D$ is the dimension of the system). This implies that the table-top method is only weakly sensitive to small "Yukawa" deviations from Coulomb's law, and so the theorem constitutes a rebuttal to the suggestion that the method can improve present limits on the photon mass. Instead it appears that Franken and Ampulski have devised a sensitive test of Faraday's Law.

It has recently been proposed by Franken and Ampulski that it may be possible to establish a new upper limit on the photon mass by means of measurements on an oscillating circuit with a frequency about 1 rad/sec. We show that the argument in this paper is in error, and that in reducing the size of their apparatus from the photon's conjectured Compton wavelength to table-top size the authors have lowered the sensitivity of their experiment by the same ratio.

It is shown that both small-dimensional, extremely low-frequency resonant circuits and long coaxial cables are unsuited to the setting of significant limits on the photon rest mass.

It is proposed to search for low-frequency components of gravitational waves by attempting to detect intensity fluctuations of light that has traveled over transmission paths crossed by gravitational waves.

We assume that the imaginary part of any inelastic hadronic amplitude is dominated by the peripheral ($l\sim \mathrm{qr}$) resonances, and that the same imaginary part can also be described by a combination of $t$-channel poles and cuts. The strength of the required cut term is determined by whether or not the pole term itself is already peripheral. The real part has no reason to be peripheral and can be determined easily from the peripheral imaginary part only when the cuts happen to be relatively weak. These assumptions lead to a successful qualitative description of all $\mathrm{}\left|t\right|\mathrm{}\sim 0.6$-Be${\mathrm{V}}^2$ dip effects in vector- and tensor-exchange inelastic and elastic reactions.

The reaction $\pi d\to N\Delta$ is studied as a probe of the $\Delta \Delta$ content of the deuteron. Assuming a $\Delta$-exchange mechanism, the cross section is expected to be 10-100 μb at 1 GeV for an estimated probability of about 1% for the $\Delta \Delta$ configuration.

To establish a relationship between new results in the classical hydrodynamic theory of ideal charged or uncharged fluids and the theory of quantum fluids, we propose that the classical vorticity field $\overrightarrow{\omega }$ have the interpretation that the flux of $\frac{\overrightarrow{\omega }}{\kappa }(\kappa =\frac{h}{m})$ through a circuit $C$ is the probability that a quantized vortex threads the circuit. The new classical results, which apply to both charged and uncharged fluids, follow from an introduction of the conserved vorticity current tensor. It allows us to describe the dynamical behavior of the vorticity field and leads to an explicit hydrodynamic model for how fluctuations can create the distribution of vortex rings proposed by Iordanskii.

First measurements of double-photon elastic scattering performed on liquids with centrosymmetric molecules yield good agreement with statistical molecular theory of nonlinear light scattering. Studies of this new scattering are shown to allow determination of the third-order molecular polarizability as well as its anisotropy, and to promise information on the structure of short-range molecular ordering and electric properties of molecules.

Field errors have been observed to cause anomalous loss to an internal hoop and produce convection patterns which have potentials $\sim \frac{k{T}_e}{e}$. A simple model of plasma flowing along field lines accounts semiquantitatively for the observed anomalous loss and the production of convection patterns. The addition of a small (5%) toroidal field reduces the anomalous loss by a factor of 60 to the level given by classical ion-neutral diffusion across the field.

The thermodynamics of the Heisenberg-Ising ring is reduced to the solution of a system of recurrent nonlinear integral equations.

It is shown that, for a Tokamak plasma with fixed boundary, the toroidal contributions to the shear are sufficiently important to modify the $j_{\parallel }$-kink instability. Assuming that $\beta$ is small and using the energy principle, $\delta W$ is calculated to order ${\left(\frac{r}{R}\right)}^6$ and the toroidal corrections are shown to change the sign of the destabilizing term. One consequence is that the range of rotational transform angles for which the $m=1\mathrm{}$, $\nu =1\mathrm{}$ instability will occur, when the shear is weak, is below the Kruskal-Shafranov limit and not above it. Also, the new terms have an important stabilizing effect for the screw pinch.

We have observed a Curie-Weiss temperature dependence for electron critical scattering in In-EuS junctions which applies to within a few degrees of the ordering temperature $T_c$. The law holds both above and below $T_c$ from 4.2 to 300°K. Above $T_c$ the magnetoconductance is $G(H,T)=G_0(T-T_c)+G_{1}T{H}^2{(T-T_c)}^{-2\mathrm{}}$, where $G_0$ and $G_1$ are constants. These results are explained by a model based on critical scattering in the mean-field limit.

The photoelectric yield of a thin lead film has been measured between 2.5 and 12°K. There is a difference in temperature dependence between the normal and superconducting states which is in reasonable agreement with the BCS-based theory of Slezov. A value for the energy gap is obtained which is consistent with infrared and tunneling measurements of other observers. The size of the change in yield, however, is more than an order of magnitude larger than that predicted and is presently not understood.

Experimental measurements of the optical mass of copper are interpreted to yield a Fermi-surface average of the Landau parameter which relates the current carried by a quasiparticle excitation to its velocity.

Synchrotron radiation has been used to measure the reflectance spectra of KCl, KBr, RbCl, CsCl, CsBr, Ca${\mathrm{F}}_2$, Sr${\mathrm{F}}_2$, and Ba${\mathrm{F}}_2$ for photon energies $6<\mathrm{}\hslash \omega <36\mathrm{}$ eV at temperatures $90<T<\mathrm{}400\mathrm{}$ K. Excitations of both valence and core electrons show sharp structure and strong $T$ dependence. Analysis of the data in terms of excitonic and interband transitions from core states is made with regard to $T$ dependence, crystal structure, and chemical composition.

The effects of single Fe impurities on the Cu-host NMR in $\mathrm{Cu}\mathrm{Fe}$ have been measured over a wide range of Fe concentrations up to 45 kOe at 1.65°K. The additional impurity $d$-spin conduction-electron spin-correlation effects on the host NMR linewidth originally noted by Golibersuch and Heeger have been shown to be the result of single Fe impurities in the Kondo state; these effects are destroyed at lower applied fields with increasing Fe concentration as a result of Fe-Fe interactions.