The compound triethylenetetrammonium hexachlorocuprate(II), [${\mathrm{C}}_6$${\mathrm{H}}_{22}$${\mathrm{N}}_4$]Cu${\mathrm{Cl}}_6$, exhibits two-dimensional magnetic behavior in the temperature range 20-75 K with an exchange constant of $\frac{J}{k}=19.4\mathrm{}$ K derived from a fit of the data by the expansion of Baker et al. There is a phase transition to an antiferromagnetic state at 8.95 ± 0.1 K, and the magnetization data suggest metamagnetic behavior.

When the $R_1$ line in ruby is swept with a tunable laser from the center to the wings, the ratio of trap emission to $R_1$ emission remains constant up to a point in the line where it suddenly drops to a lower constant value out to the wings. We suggest that this break corresponds to mobility edges separating delocalized states in the central region from "localized" states beyond this break.

A gauge model is proposed which contains only left-handed currents of quarks and leptons. The nuclear $\beta$-decay current couples to the intermediate boson with partial strength of the gauge coupling, and a new mixing angle is introduced to ensure the universality of the $\beta$ decay and the $\mu$ decay.

We address the question, how many kinds of new quantum numbers ("charm") are indicated by recent experimental developments in the study of $e^{+}-e^{-}$ collision phenomena and dimuon production in neutrino and antineutrino reactions?

A pair of heavy leptons with a mass of 1.8 GeV can explain the step-function-like behavior of the charge-particle energy fraction in $e^{+}{e}^{-}$ annihilation except for the resonance region around 4.1 GeV. The preliminary result of the $e-\mu$ events reported by Perl, in particular the effects of spin alignment, are discussed in terms of this heavy lepton. We comment on a possible way to distinguish the heavy lepton from heavy hadrons.

The $n-n$ angular correlation for neutrons emitted in spontaneous fission of ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$ has been measured. Discrepancies are observed when these and other experimental observations are compared with Monte Carlo calculations based on the evaporation model. It is suggested that the discrepancies could be attributed to enhanced neutron emission along the fission axis.

The angular distribution of positrons emitted in the decay of polarized ${}_{}{}^{19}{}_{}{}^{}\mathrm{Ne}$ has been measured as a test for the second-class weak interaction. The $\beta$ asymmetry parameter varies linearly with the $\beta$ energy with slope ${\left(\frac{\mathrm{dA}}{\mathrm{dE}}\right)}_{\exp }=(-0.65\mathrm{}\pm 0.15)\%$ Me${\mathrm{V}}^{-1\mathrm{}}$. This result requires a second-class form factor comparable to the weak-magnetism term.

Measurements of the tensor analyzing powers for ($d, t$) reactions on ${}_{}{}^{118}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ are presented. It is shown that the measured quantities are sensitive to the $D$-state components in the triton wave function. The magnitudes of the observed analyzing powers are in good agreement with predictions obtained from a triton $D$-state wave function calculated in first-order perturbation theory.

Noncharacteristic radiations in atomic and molecular collisions are examined. A new mechanism is considered in which electrons are induced to radiate collectively. The collective radiations are present even in the absence of inner-shell vacancies. The importance of this mechanism increases with collision energy and the number of electrons. The emitted photon energy increases with collision energy and can exceed the united-atom limit. The asymmetries of the noncharacteristic radiation are examined.

The hydrodynamics of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$ in the vicinity of the phase transition is generalized to include an extra variable, the magnitude of the order parameter. Its equation of motion is derived and added to the set of hydrodynamic equations. The effect on the dissipation and dispersion of first, second, and fourth sound is calculated. First sound is found to be anisotropic and a pair of new propagating modes is predicted.

Measurements of the temperature and pressure dependences of Raman and elastic light scattering were used to investigate the dynamics of the tricritical point in SbSi at $T\cong 235°$ K and $P\cong 1.4$ kbar. The results are discussed in terms of a mean-field treatment of tricritical points.

Gaps in the acoustic attenuation for wave vectors satisfying the Bragg condition have been observed in a mixture of cholesteryl choloride and cholesteryl myristate.

We obtain a first-order phase transition in metallic vapors under high pressure which is due to the fact that the equation of the law of mass action for the ionization processes does not have a unique solution. One of the consequences is a gradual nonmetal-metal transformation.

The photoluminescence excitation spectra of excitons in GaP, bound to isoelectronic electron traps by more than 40 meV, show series of levels whose energies agree well with effective-mass calculations of the $\mathrm{nS}$ levels of an acceptor, which are inaccessible by other techniques. This is the first detailed investigation of the internal structure of excitons bound to isoelectronic traps. It confirms the Hopfield-Thomas-Lynch model and establishes its range of validity.

Photoemission spectra at $h\nu =21.2\mathrm{}$ eV reveal two $5p$ levels for xenon physisorbed on a tungsten (100) surface. The spin-orbit splitting of the two levels and their intensity ratio correspond closely to gas-phase measurements, while the $5p_{\frac{3}{2}}$ peak is significantly broadened with respect to the $5p_{\frac{1}{2}}$. We interpret the broadened structure as an unresolved doublet resulting from splitting the Xe $5p_{\frac{3}{2}}$ states in the tungsten-surface crystal field.

The effect of the $2\Delta$ recombination phonons in modifying the effective lifetime ${\tau }_{\mathrm{eff}}$ for quasiparticle recombination has been determined for the first time in a double-junction experiment by comparing measurements taken both with and without a helium film covering the junctions. For a double junction made from evaporated aluminum films 300 Å thick deposited on a glass substrate, we find $\frac{{\tau }_{\mathrm{eff}}}{{\tau }_R}=8.6\mathrm{}\pm 1.1$ in the absence of the helium film, and, at $\frac{\Delta }{\mathrm{kT}}=6\mathrm{}$, ${\tau }_R=1.4\mathrm{}\pm 0.1$ μsec.

Inclusive hadron production in muon-proton inelastic scattering has been measured for $q^2>0.5\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ and $10<\mathrm{}\nu <135\mathrm{}$ GeV. The results are presented in the form of the transverse momentum distribution of charged hadrons and the hadron invariant structure function $F\left(x^{\prime }\right)$. Results are given for different regions of $q^2$ and $s$.

We report on a search for decays of long-lived penetrating neutral particles in the neutrino beam at Fermilab. We find an event rate consistent with background which corresponds to a fraction (7±5)×${10}^{-3\mathrm{}}$ of ${\nu }_{\mu }\left({\overline{\nu }}_{\mu }\right)$ scattering in liquid scintillator. This result poses an apparent contradiction to the observations of Krishnaswamy et al. in the Kolar Gold Mines.

We have found events of the form $e^{+}+e^{-}\to e^{\pm }+{\mu }^{\mp }+\mathrm{missing}\mathrm{energy}$, in which no other charged particles or photons are detected. Most of these events are detected at or above a center-of-mass energy of 4 GeV. The missing-energy and missing-momentum spectra require that at least two additional particles be produced in each event. We have no conventional explanation for these events.

The newly discovered psion family can be described by mass-squared linear Regge trajectories. The new $J^{\mathrm{PC}}$ assignments are for 2.8 GeV/${\mathit{c}}^2$, $0^{++}$, and for the 3.4 region, $2^{++}$, $1^{-+}$, $0^{++}$. All radiative decays are related through a single $S_{\mu \nu }{F}_{\mu \nu }$ coupling. A good fit is obtained.