The Seebeck coefficient can be related to the specific heat of the charge carriers. Experiments on the itinerant ferromagnet nickel show that the specific heat determined from the Seebeck effect agrees closely with that determined from conventional specific-heat measurements.

Optical transmission and reflectance were measured on natural magnetite single crystals in the spectral range $0.15<~h\nu <~0.75$ eV. These measurements below and above the semiconductor-to-metal transition temperature $T_{\mathrm{v}}$ have shown that, unlike for the vanadium oxides, there is no collapse of the optical gap at the transition. The present results and the existing data on the transport properties of magnetite indicate that different bands contribute to the electric conduction above and below $T_{\mathrm{v}}$.

The polarization of an 8-12-MeV proton beam produced by a Lamb-shift ion source has been determined with 0.4% absolute accuracy by an atomic-beam technique. The procedure, which involves selection of a single hyperfine state of fast $\mathrm{H}\mathrm{}\left(2s\right)\mathrm{}$ atoms, is ideally suited to routine monitoring of beam polarization. Absolute $p-{}_{}{}^4{}_{}{}^{}\mathrm{He}$ elastic-scattering analyzing powers measured with the calibrated beam are reported, and existing double-scattering data are compared with these results.

The magnetic moments of the ${\frac{7}{2}}^{-}$ states at 1.610 MeV in ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ar}$ and 1.380 MeV in ${}_{}{}^{37}{}_{}{}^{}\mathrm{K}$ were measured by differential spin-precession methods. The moments, together with the remeasured halflives, are $\mu =-1.33\mathrm{}\mathrm{}\left(5\right)\mathrm{}{\mu }_N$ and $T_{\frac{1}{2}}=4.6\mathrm{}\mathrm{}\left(2\right)\mathrm{}$ nsec for ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ar}$, and $\mu =+5.2\mathrm{}\mathrm{}\left(3\right)\mathrm{}{\mu }_N$ and $T_{\frac{1}{2}}=10.5\mathrm{}\mathrm{}\left(5\right)\mathrm{}$ nsec for the ${}_{}{}^{37}{}_{}{}^{}\mathrm{K}$ state. The prediction of the Sachs mirror theorem is shown to hold, and systematic trends in ${\frac{7}{2}}^{-}$-state moments of $1f_{\frac{7}{2}}$-shell nuclei are examined.

We formulate a method for obtaining a semiclassical expression for the single-particle density of states from the partition-function approach. In some simple solvable models, the semi-intuitive Strutinskii prescription is demonstrated to yield essentially identical results for shell correction and the proposed semiclassical procedure. This gives us greater confidence in the Strutinskii method.

The coherent bremsstrahlung from a 50-μm-thick crystal of silicon was collimated to $0.234\left(\frac{m_e{c}^2}{E_1}\right)$ rad with the incident energy of the electrons $E_1=1\mathrm{}$ GeV. The energy spectrum shows a sharp spike with the signal-to-background ratio greater than 10 and the half-width $\Delta k=15\mathrm{}$ MeV at a photon energy $k=185\mathrm{}$ MeV. The spectrum is in good agreement with theory based on Überall's treatment. A maximum intensity of 2×${10}^4$ photons/MeV sec has been obtained at the spike.

We report results from a counter and optical spark-chamber-spectrometer experiment on the $\beta$ decay of polarized $\Lambda$ hyperons. A sample of 218 decays, constituting approximately one third of the total data, has been identified. The measured up-down asymmetries from a selected subsample of 173 events are $A_v=0.67\mathrm{}\pm 0.18$, $A_e=0.14\mathrm{}\pm 0.17$, and $A_p=-0.55\mathrm{}\pm 0.18$. When interpreted in the framework of a $V-A$ theory with no second-class currents ($g_2=0\mathrm{}$), they confirm the sign of the form-factor ratio $\frac{g_1}{f_1}$ as given by the Cabibbo model, but favor a somewhat smaller magnitude.

Systems containing bound and free particles are described by simple Bose or Fermi fields, one representing bound particles and others representing free particles. The lack of proper symmetry for states corresponding to given numbers of bound and free particles is corrected by drawing a correspondence (partial isometry) between proper physical states and these. When transformed to the new basis, the Hamiltonian is found to contain non-particle-conserving terms and exchange terms.

The cross sections for pair production of quarks in proton-nucleus collisions are calculated using the cross section for the production of massive photons measured by Christenson et al. in a recent $\mu$-pair experiment. A comparison with upper limits on the total quark production cross section measured at CERN and Serpukhov reveals that pointlike fractionally charged quarks with mass ≲ 3 GeV/${\mathit{c}}^2$ do not exist as free particles.

An eikonal expansion is considered which yields an impact-parameter representation for the scattering $T$ matrix. The dependence on momentum transfer is summed to all orders by means of a conjecture to obtain a standard impact-parameter representation. As a result, phase-corrected eikonal formulas are obtained which are shown to improve on the Glauber approximation systematically at large scattering angles, in contrast to the Abarbanel-Itzykson approximation. Regge behavior is found.

The $s\leftrightarrow u$ symmetry of $s$-channel helicity amplitudes is investigated without the exchange mechanism being specified. Conclusions are drawn concerning the possibility of phase assignment to scattering amplitudes at high energy. Difficulties are found in absorption models with $J_{\Delta \lambda }{s}^{\alpha }$ behavior.

It is shown that in dual-resonance models with no ghosts the least massive spin-$J$ meson which couples to baryons must have $I=0\mathrm{}$ and $P=C={\mathrm{}(-1\mathrm{})\mathrm{}}^J$ for $J>~J_0$ (number of subtractions at $t=0\mathrm{}$), e.g., $M_{\omega }<~M_{\rho }$, $M_f<~M_{A_2}$, etc. If degeneracy occurs, e.g., $M_{\omega }=M_{\rho }$, then the $I=0\mathrm{}$, $P=C={\mathrm{}(-1\mathrm{})\mathrm{}}^J$ coupling must dominate. Inequalities are found among couplings of arbitrary-spin baryons to leading mesons. For $\omega$-nucleon coupling, $g{\gamma }^{\mu }+\left(\frac{\mathrm{if}}{2m}\right){\sigma }^{\mu \nu }{q}_{\nu }$, with $M_{\omega }<M_{\rho }$ one finds that $g^2>~{\left(\frac{f{M}_{\omega }}{2m}\right)}^2$. With $\omega -\rho$ degeneracy, $g_{\omega }^{}{}_{}{}^2-g_{\rho }^{}{}_{}{}^2>~{\left(\frac{M_{\omega }}{2m}\right)}^2|f_{\omega }^{}{}_{}{}^2-f_{\rho }^{}{}_{}{}^2|$. Bounds on SU(3) mixing angles and baryon masses are also found.

We have investigated the angular aspect of metastability exchange collisions between ground-state and $2{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}$ metastable ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ atoms theoretically and experimentally. Coupling between the orientations of the two $2{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}$ hyperfine levels and partial coherence survival after a collision are shown to be important. We propose a different interpretation of previous experiments, and we suggest a new value of the metastability exchange cross section: $\sigma =(7.6\mathrm{}\pm 0.4)\times {10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$. The case of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixtures is also studied.

It is shown that the second-order perturbation expression for the diamagnetic susceptibility of electrically neutral atoms and molecules can be put in a completely gauge-independent form, even when the susceptibility is expressed in terms of approximate zeroth-order wave functions. It is further shown that the natural choice of the origin of electronic coordinates is the center of nuclear charge of the molecule.

Measurements of collisional quenching of metastable hydrogen by helium in the thermal region ($v\simeq 5\times {10}^{-3\mathrm{}}$ a.u.) have been made. The resulting cross section ${\sigma }_Q\simeq 8\times {10}^{-15\mathrm{}}$ ${\mathrm{cm}}^2$ per atom is 20-25% larger than the theoretical results obtained by Byron and Gersten using a pseudopotential method.

New measurements of $\Delta \nu$ for muonium in argon at low pressures and at very weak magnetic field provide the first observation for muonium of a quadratic term in the hfs pressure shift and lead to a new precise value for the hfs interval in muonium, $\Delta \nu =4463.311\mathrm{}\left(12\right)\mathrm{}$ MHz.

The existence of emission lines at the low-energy sides of the $L{\beta }_{2, 15}$ and $L{\lambda }_1$ x-ray lines in the rare-earth elements has been experimentally detected. Their intensities and positions relative to those of the $L{\beta }_{2, 15}$ and $L{\gamma }_1$ lines have been measured and are presented as functions of the atomic number of these elements.

Satellites on $2p$ photoelectron spectra of transition-metal ions are shown to arise from simultaneous outer-shell excitation. The coupling mechanism and selection rules are discussed. Energies of the $3d\to 4s$ transition have been obtained for a number of difluorides and oxides.

The Feynman-Cohen model for rotons is shown to lead to an attractive interaction for two rotons at large distances and a repulsive interaction at short distances. The attractive interaction leads to a bound state of $d$ symmetry in agreement with recent light-scattering data. The scattering of rotons arises from the repulsive interaction, and the experimental data on roton-roton scattering lead to an estimate of the range of repulsive interaction.

We show that the leading low-temperature behavior of the nth cluster coefficient $b_n$ can be calculated without sloving the $n$-body problem, and that there is a $\ln T$ term in the expansion. We illustrate these results particularly for the case of $b_3$.