The real and imaginary parts of the $E2-M1\mathrm{}$ mixing ratio of the 73-keV transition in ${\mathrm{Ir}}^{193}$ have been determined in an arrangement that requires no correction for Faraday rotation. The values $\mathrm{Re}\delta =+0.556\mathrm{}\pm 0.010$ and $\mathrm{Im}\delta =(+0.6\mathrm{}\pm 2.1)\times {10}^{-3\mathrm{}}$ result in a phase angle between $E2\mathrm{}$ and $M1\mathrm{}$ of $\eta =(+1.1\mathrm{}\pm 3.8)\times {10}^{-3\mathrm{}}$, thus showing no evidence for $T$ non-conservation.

We show that in the covariant approach there exist no systems of single-particle functions satisfying a completeness property which generate any acceptable single-particle representations of current algebras and superconvergence relations. The nonexistence of any acceptable local infinite-component field theory or wave equation is also demonstrated.

We present evidence showing that neutral excitations which are not photons are produced in superfluid liquid helium in the presence of a ${\mathrm{Po}}^{210}$ alpha-particle source. At low temperatures these excitations travel through the liquid with negligible scattering. They have sufficient energy to generate positive ions and electrons at the surface of the liquid or at a suitable metal plate immersed in the liquid.

We deduce that the "apparent" spin-diffusion coefficient $D_{\mathrm{eff}}$ measured by the spin-echo technique should show a maximum as a function of temperature. The effect is estimated to lie in the experimentally attainable range for both pure ${\mathrm{He}}^3$ and dilute mixtures, and should give a direct value of the Fermi-liquid parameter $Z_1$.

We consider a new model Hamiltonian ${\mathcal{H}}^{\left(\nu \right)}$ for interacting $\nu$-dimensional classical "spins"; ${\mathcal{H}}^{\left(\nu \right)}$ reduces to the Ising, planar, and Heisenberg models, respectively, for $\nu =1, 2, \mathrm{and} 3$. Certain critical properties of ${\mathcal{H}}^{\left(\nu \right)}$ are found to be monotonic functions of $\nu$.

Results of a high-resolution study of the charged-particle energy spectrum resulting after ${\mu }^{-}$ capture in ${\mathrm{Si}}^{28}$ are presented. The spectrum, attributed mainly to proton emission, exhibits a low-energy cutoff at 1.4 MeV and a maximum at about 2.5 MeV from which it decreases approximately exponentially with a decay constant of 4.6 MeV. A branching ratio of 0.15±0.02 charged particle per capture was determined.

The ($p, p$) polarization asymmetry has been measured at 20.2-MeV laboratory energy with an accuracy as good as ±0.001. The results are consistent with the phase-shift analyses at this energy.

Using the three-triplet model and the unique assignments in this model for the resonances $N\left(1466\right)\mathrm{}$, $Z_0\mathrm{}\left(1863\right)\mathrm{}$, and $Z_1\mathrm{}\left(1910\right)\mathrm{}$, the entire three-particle antisymmetric representation 816 of SU(18) is predicted, including the known resonances $Z_1\mathrm{}\left(2190\right)\mathrm{}$, $Z_1\mathrm{}\left(2280\right)\mathrm{}$, $N\left(1751\right)\mathrm{}{\frac{1}{2}}^{+}$, $N\left(1863\right)\mathrm{}{\frac{3}{2}}^{+}$, and $\Delta \mathrm{}\left(1934\right)\mathrm{}{\frac{1}{2}}^{+}$. The four $Z$ resonances are predicted to have $J^P={\frac{1}{2}}^{+}, {\frac{1}{2}}^{+}, {\frac{1}{2}}^{+}, \mathrm{and} {\frac{3}{2}}^{+}$, respectively.

Based on the notions of chiral dynamics and the field-current identity as applied to the broken SU(3), theoretical expressions for the form factors $f_{\pm }\mathrm{}\left(t\right)\mathrm{}$ are obtained. A small $\xi$ ($\left|\xi \right|\ll 1$) and a large $\left|{\lambda }_{-}\right|$ (an order of magnitude larger than ${\lambda }_{+}$) are predicted. [However, the product $\xi {\lambda }_{-}$ is expected to be small.]

Various predictions of the $\rho \pi \pi$ coupling constant $\frac{{f_{\rho }}^2}{4\pi }$ are discussed. A $\rho +{\rho }^{\prime }$ meson dominance model is considered with $M_{{\rho }^{\prime }}\simeq 1600$ MeV and ${\Gamma }_{{\rho }^{\prime }}\simeq 200$ MeV. This model predicts a value of the $S$-wave $\pi -N$ scattering length formula $a_1-a_3$ in better agreement with experiment than the $\rho$-dominance model when ${\Gamma }_{\rho }=128\mathrm{}$ MeV, and the modified Kawarabayashi-Suzuki-Riazuddin-Fayyazuddin relation is well satisfied.