A critical asymmetry in local fluctuations of the rotational parameter $\varphi$ in SrTi${\mathrm{O}}_3$ for $T<\mathrm{}{T}_c$ and $〈\varphi 〉\ne 0$ is observed directly by the asymmetry $a_s$ of the paramagnetic resonance lines of ${\mathrm{Fe}}^{3+}-V_{\mathrm{O}}$ pair centers. The parameter $a_s$ increases in a critical manner for $T\to {T_c}^{-}$. It is postulated that such an asymmetry is a general property of second-order phase transitions.

We report the low-temperature specific heat of one-dimensional ${\mathrm{K}}_2\mathrm{Pt}{\left(\mathrm{CN}\right)}_4{\mathrm{Cl}}_{0.3}·n\left({\mathrm{H}}_2\mathrm{O}\right)$. Within experimental accuracy the linear temperature contribution to the specific heat is zero. This result is consistent with both the variable-range and interrupted-strand hopping models.

We report initial observations of a new radiation-induced phenomenon in LiF; a large permanent electrical polarization can be induced in LiF by ionizing radiation. Specific radiation-induced polarizations, after thermal depolarization, can be regenerated optically but not by thermal repolarization. Rate parameters characterizing thermal depolarization differ from those of other thermally activated processes. This effect has a signal-to-noise ratio comparable to simultaneous thermoluminescence measurements, which suggests many practical possibilities.

The vibrational properties of Si III and Ge III have been studied experimentally using Raman spectroscopy, and theoretically using a simple force-constant model. Si III and Ge III are metastable crystalline phases with large unit cells and distorted tetrahedral bonding.

An approximate theory is developed for the magnetic dipole response of a small semiconducting sphere placed in a cavity at a point of maximum microwave magnetic field. Experiments corroborate the prediction that electric fields induced in the particle lead to resonant absorption at an applied dc magnetic field free of depolarization (magnetoplasma) shifts. The effect may enable microwave determination of effective mass in materials having carrier concentrations well above the limit for conventional cyclotron resonance.

The effect of annealing on electronic properties of vacuum-cleaved surfaces of Si is investigated by means of photoelectron and secondary-electron emission. It is found that annealing results in a change in the surface structure, which in turn influences the electronic properties of the surface, such as the work function, ionization energy, electron affinity, position of the Fermi level in the band gap, and spectrum of surface states.

The reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}({}_{}{}^6{}_{}{}^{}\mathrm{Li},d)$ has been studied at $E\left({}_{}{}^6{}_{}{}^{}\mathrm{Li}\right)=32\mathrm{}$ MeV. Clearly structured angular distributions, with maximum cross sections of the same order of magnitude as those reported for the reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$), are obtained. They are well described by $\alpha$ transfer distorted-wave Born-approximation calculations.

Spectroscopic strengths of $0^{+}$ states observed in the reaction ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, together with calculations of $\alpha$-particle widths, imply that the large $\alpha$ width of the 6.72-MeV state arises from mixing with a state of $\mathrm{fp}$-shell character. A long-standing dilemma is thus resolved.

Just as light beams can undergo position shifts when totally internally reflected, it is found that analogous shifts of an electron beam can occur upon total reflection at a potential barrier. A given shift corresponds to a spin polarization normal to the shift, and thus an initially unpolarized beam will be separated into two polarized beams. These shifts are comparable to the electron Compton wavelength times the number of multiple reflections.

Measurements are reported for the process $e+p\to e+{\pi }^{+}$ + anything. Partial multiplicities and average transverse momenta show no significant dependence on $Q^2$.

The electroproduction of hadrons was studied with a wide-aperture spectrometer. Inclusive data are presented for the electron-scattering region $-0.5>q^2>-2.5\mathrm{}{\left(\frac{\mathrm{GeV}}{c}\right)}^2$, $4<\mathrm{}\nu <14\mathrm{}$ GeV. Distributions of the electroproduced hadrons in the three inclusive variables $\varphi$, ${p_{\perp }}^2$, and $x$ are studied in the region $x>\mathrm{}0\mathrm{}$. A striking difference from photoproduction is observed in the excess of positive over negative hadrons at high $x$ and high $q^2$.

We present a model-independent amplitude analysis of the reaction $K^{-}p\to {\pi }^{-}{Y}^{*+}\mathrm{}\left(1385\right)\mathrm{}$ at 3.9 and $4.6\frac{\mathrm{GeV}}{c}$ incident momenta. By observing the two-step decay of the $Y^{*+}\mathrm{}\left(1385\right)\mathrm{}$ we determine the magnitudes and two relative phases of the four independent transversity amplitudes which describe the reaction. These amplitudes are found to be in rough agreement with the predictions of the naive quark model; however, the predictions do not hold exactly.

Through generalized $t$-channel unitarity relations we argue that in a diffractive picture, it is unlikely for the high-energy elastic forward peak to be of a simple exponential form. The threshold behavior near the $2\pi$ branch point suggests that the diffraction slope will continuously increase with decreasing $\mathrm{}\left|t\right|\mathrm{}$ in the very forward direction.

A method of calculating inelastic hadronic processes is proposed in which massive states are produced by Regge exchange and decay into final states with coupling strengths given by the statistical bootstrap of Frautschi. The invariant-mass distributions for a particular final state are peaked slightly above threshold and fall off exponentially with increasing mass. Good agreement with experiment is obtained for numerous reactions.

We report the direct experimental observation of superelastic collisions of vibrationally excited $\mathrm{H}_2^{}{}_{}{}^{+}$ ions with atomic and molecular targets. Energy-change spectra taken with $\mathrm{H}_2^{}{}_{}{}^{+}$ incident on He, Ne, Ar, Kr, and ${\mathrm{H}}_2$ targets show a strong dependence of the cross section on the atomic number of the target. The cross sections for superelastic collisions were observed throughout the kinetic-energy range 100-1500 eV and they appear to be largest in the region 100-500 eV, decreasing slowly at higher energies.

The lifetime of the $2S$ state of ${\mathrm{He}}^{+}$ has been measured by counting decay photons versus time from an ensemble of excited ${\mathrm{He}}^{+}$ ions stored in an electromagnetic trap of the Penning type. The result is ${\tau }_{2S}=1.922\mathrm{}\left(82\right)\mathrm{}$ msec. This is in agreement with the theoretical value of 1.899 msec. The agreement between theory and experiment implies a new upper limit on the amount of parity impurity in the $2S$ wave function.

The natural lifetime of the $2S$ state of ${\mathrm{He}}^{+}$ has been measured in a decay-in-flight experiment. The result, $\tau ={2.04}_{-0.34\mathrm{}}^{+0.81\mathrm{}}$ msec, is consistent with the theory of two-photon spontaneous emission and determines an upper bound $\lambda <~8\times {10}^{-5\mathrm{}}$ for the coupling constant of the pseudoscalar "anapole" interaction.

Momentum distributions of electrons bound in the $K$ and $L$ shells of carbon have been separately measured. Data obtained from the angular distribution of coincidences between the two electrons outcoming in a quasifree ($e,2e$) process are compared with theoretical predictions.

Short-lived temperature spikes have been observed following Coulomb excitation in rare-earth oxides. The thermal aftereffects were detected by observing the Mössbauer effect in the decay of Coulomb-excited states of ${\mathrm{Ho}}^{165}$, ${\mathrm{Lu}}^{175}$, and ${\mathrm{Er}}^{167}$. The results are in reasonable agreement with a simple model based on heat-flow theory.

We present a new method of solving analytically the time-dependent Boltzmann transport equation. Two examples are given to demonstrate the use of this method to predict ac and dc conductivities in nondegenerate single-valley simiconductors.