We have observed surface electric-field-induced and resonance-enhanced Raman scattering by $q\approx 0$ LO phonons in the spectra obtained from InSb surfaces. The data indicate that excitons are responsible for the resonance enhancement. The effects of temperature and externally applied electric fields are discussed. The results suggest the possibility of studying the surface electronic properties by Raman spectroscopy.

The conduction-electron $g$ factor of the $\Gamma$ centered surface of Pt is determined from de Haas-van Alphen spin splitting zeros. A theoretical interpretation of the electron $g$ factor in metals is presented.

Pulsed-field measurements of the antiferromagnetic-to-ferromagnetic transition in ${\mathrm{Fe}}_{2-x}{\mathrm{Mn}}_x\mathrm{As}$ show the existence of a threshold field-temperature point above the zero-field transition temperature. The antiferromagnetic-to-ferromagnetic transition cannot be induced below the threshold point by 22 × ${10}^{-6\mathrm{}}$- to 440 × ${10}^{-6\mathrm{}}$-sec rise-time pulses although the transition is produced by static fields. Similar behavior is shown by ${\mathrm{Mn}}_{1.8}$-${\mathrm{Cu}}_{0.2}$Sb and RbFe${\mathrm{F}}_3$. Possible explanations of the effect are discussed.

A new carrier-generation mechanism is observed in anthracene and is attributed to singlet-triplet annihilation. The rate constant for ionization following this annihilation is estimated to be ${\alpha }_{\mathrm{ST}}\simeq {10}^{-12\mathrm{}}$ ${\mathrm{cm}}^3$ ${\sec }^{-1\mathrm{}}$. The experiments give also a new value for the singlet-singlet annihilation rate constant, ${\alpha }_{\mathrm{SS}}\simeq {2.10}^{-11\mathrm{}}$ ${\mathrm{cm}}^3$ ${\sec }^{-1\mathrm{}}$. The possibility of other interpretations of the data is discussed.

We consider a cosmic-ray muon model in which a "directly produced" muon component with the same slope as the primary spectrum is added to the conventional pion-derived muons. It is found to be consistent with recent burst measurements, horizontal-air-shower data, atmospheric gamma-ray fluxes, and muon spectrograph measurements. It may also explain the anomalous mu-less air showers. The model requires that the photonuclear cross section increase at very high energies.

A small radial electrical potential gradient has been observed to exist across a Duraluminum rotor spinning at high speed in air at pressures from ${10}^{-5\mathrm{}}$ to ${10}^{-6\mathrm{}}$ Torr.

We have tested experimentally the model that the three regions seen in $p-p$ elastic scattering are the diffraction scattering due to $\pi$, $K$, and $\overline{p}$ production. The inelastic $p-p$ cross section was measured on circles of constant $P_{\mathrm{c}.\mathrm{m}.\mathrm{}}$. One contained a pure sample of inelastic $\pi$ events; the other, both $\pi$ and $K$ events. The cross section has a break on both circles showing that the break is not due to $K$ mesons and that the model is wrong.

The cross section for the process $\gamma p\to p\eta$ was studied from 0.8- to 1.45-GeV incident photon energy at center-of-mass angles from 50 to 90°. The data cover a range of energies well beyond previous measurements. The results will aid in the study of $I=\frac{1}{2}$ nucleon isobars.

We have measured the branching ratio $\frac{(K_L\to \gamma \gamma )}{(K_L\to 3{\pi }^0)}$ to be (2.24 ± 0.28) × ${10}^{-3\mathrm{}}$. Combined with a recently reported branching ratio $\frac{(K_L\to 3{\pi }^0)}{(K_L\to \mathrm{all}\mathrm{modes})}=0.209\mathrm{}\pm 0.011$, we find $\frac{(K_L\to \gamma \gamma )}{(K_L\to \mathrm{all}\mathrm{modes})}$ to be (4.68 ± 0.64) × ${10}^{-4\mathrm{}}$.

We have measured the branching ratio $\frac{(K_L\to 2{\pi }^0)}{(K_L\to 3{\pi }^0)}$ to be (4.6±1.1) × ${10}^{-3\mathrm{}}$. Combined with a recently reported branching ratio $\frac{(K_L\to 3{\pi }^0)}{(K_L\to \mathrm{all}\mathrm{modes})}=0.209\mathrm{}\pm 0.011$, we find $\frac{(K_L\to 2{\pi }^0)}{(K_L\to \mathrm{all}\mathrm{modes})}=(0.96\mathrm{}\pm 0.23)\times {10}^{-3\mathrm{}}$ and $\left|{\eta }_{00}\right|=(2.3\mathrm{}\pm 0.3)\times {10}^{-3\mathrm{}}$.

Total cross sections for the processes $K^{-}p\to \Lambda {\pi }^{+}{\pi }^{-}$ and $K^{-}n\to \Lambda {\pi }^{-}{\pi }^0$ (pure $T=1\mathrm{}$) have been measured as a function of center-of-mass energy. From these the $\Lambda \pi \pi$ $T=0\mathrm{}$ cross section was determined. The data indicate the existence of a $\Lambda \pi \pi$ decay of the $Y_0^{}{}_{}{}^{*}\mathrm{}\left(1690\right)\mathrm{}$.

We have performed a search for $I=2\mathrm{}$ multipion resonances (${\chi }^{--}$) in reactions of the type ${\pi }^{-}n\to p{\chi }^{--}$, where ${\chi }^{--}$ decays into ${\pi }^{-}{\pi }^{+}{\pi }^{-}{\pi }^{-}$ with or without extra ${\pi }^0$ mesons. Our results at a ${\pi }^{-}$ beam momentum of 7 GeV/c indicate that if these resonant states exist and if they have widths of ≤160 MeV, then they are produced only with cross sections which are one to two orders of magnitude lower than the production cross sections measured for the well-established resonances.

We have measured the antiproton-proton elastic differential cross section in the center-of-mass angular range $cos\theta =-0.985\mathrm{} \mathrm{to} +0.40\mathrm{}$ at six momenta between 1.6 and 2.2 GeV/c in a bubble-chamber experiment. We use the data to look for evidence of direct-channel boson resonances.

Evidence is presented for the existence of a baryon with a strangeness $S=-2\mathrm{}$, mass $M=1930\mathrm{}\pm 20$ MeV, and width $\Gamma =80\mathrm{}\pm 40$ MeV. It is speculated that this resonance completes a $J^P={\frac{5}{2}}^{-}$ octet. An SU(3) analysis of the conjectured ${\frac{5}{2}}^{-}$ octet gives a reasonable overall description of the partial widths of the member states.

Large samples of $Y_1^{}{}_{}{}^{*}{\mathrm{}\left(1660\right)\mathrm{}}^{\pm }\to {\Sigma }^0{\pi }^{\pm }$ have been analyzed. Little $\Lambda \pi$ decay is observed, but $\Sigma \pi$ and $Y_0^{}{}_{}{}^{*}\mathrm{}\left(1405\right)\mathrm{}\pi$ modes are comparable. The spin and parity conclusion from ${\Sigma }^0\pi$ study is ${\frac{3}{2}}^{-}$.

We show that $T$ is not conserved in the $\mathrm{CP}$-nonconserving $K^0\to 2\pi$ decays by direct data analysis (rather than inferentially via $\mathrm{CPT}$) over a considerable range of values for the Wu-Yang parameters within the span of existent data. In particular, if $\frac{\left|{\eta }_{00}\right|}{\left|{\eta }_{+-}\right|}<~1.0$, then $T$ is broken. This result is independent of the final state $\pi \pi$ interaction.

The observed anomalous decrease in the ${\mathrm{P}}^{31}$ spin-lattice relaxation time on approaching the Curie point in a very pure K${\mathrm{H}}_2$P${\mathrm{O}}_4$ crystal is explained as being due to magnetic dipolar coupling to the temperature-dependent ferroelectric mode.

Observations of the temperature-dependent resistivity of aluminum, indium, sodium, and potassium have shown a $T^2$ term to exist in the resistivity of indium and aluminum, but not in sodium or potassium.

It is proposed that the dominant mechanism for electrical conduction in NiO and similar materials is by means of holes in the oxygen $2p$ band. A band-structure diagram which takes into account the primarily localized $3d$ states is suggested.