Model calculation based on associated production of charmed (and new) hadrons is presented for the characteristics of trimuon and like-sign—dimuon production in neutrino scattering. They are in general agreement with the qualitative features of the data. Discussions are given with emphasis on comparing the present model with the model based on sequential decays of heavy leptons.

A number of striking features in high-energy lepton scattering have forced a re-examination of the standard four-quark-parton models: Recent data show (i) at small $x$ in $\mu N\to \mu X$, $\nu W_2$ increases as $Q^2$ increases; for increasing $E$ in $\nu N\to \mu X$, there are rises in (ii) ${〈y〉}^{\overline{\nu }}$ and (iii) $\frac{{\sigma }^{\overline{\nu }}}{{\sigma }^{\nu }}$. We introduce a $W$ dependence to the sea-quark distributions (motivated by the possible existence of multiquark exotic states) and obtain satisfactory fits to the data (i)-(iii).

Using the Fermilab 15-ft neon-hydrogen bubble chamber we have identified seventeen events of the type ${\nu }_{\mu }N\to {\mu }^{-}{e}^{+}X$. The ratio of the production of these events to ordinary neutrino charged-current events is (7.7 ± 3.0) × ${10}^{-3\mathrm{}}$ for positron energy greater than 800 MeV and neutrino energy greater than 800 MeV and neutrino energy greater than 10 GeV. Associated with these seventeen events are 11 $V\text{'}\mathrm{s}$, of which eight fit ${K_s}^0\to {\pi }^{+}{\pi }^{-}$ and three fit ${K_s}^0\to {\pi }^{+}{\pi }^{-}$ and $\Lambda \to p{\pi }^{-}$ ambiguously. The average $K^0$ multiplicity per ${\mu }^{-}{e}^{+}$ event is determined to be ${1.84}_{-0.53\mathrm{}}^{+0.63\mathrm{}}$.

We consider the possibility that weak interactions—in common with all other known interactions—do in fact enjoy a left-right symmetry manifest in the Hamiltonian, and that parity nonconservation stems from the spontaneous breakdown of this symmetry. We show that this picture is experimentally distinguishable from the conventional one in which parity nonconservation stems from the Hamiltonian. The implications of currently available experimental results are discussed and the need for new and decisive experiments is underlined.

With the use of a new feedback levitation electrometer (with an increase in sensitivity by ${10}^3$ in comparison to our previous graphite experiments) iron objects of mass ∼ 2 × ${10}^{-4\mathrm{}}$ g have been explored for fractionally charged quarks and/or a possible electron-proton charge difference. Upper limits found were $\frac{N\left(\mathrm{quarks}\right)}{N\left(\mathrm{nucleons}\right)}<3\mathrm{}\times {10}^{-21\mathrm{}}$ and $\frac{(Q_p-|Q_e\mathrm{}\left|\right)\mathrm{}}{Q_p}<{10}^{-21\mathrm{}}$. The present "sensitivity" is ∼ ${10}^7$ times that of the original Millikan experiment.

Cross sections for elastic scattering of 175-300-MeV electrons by the nuclear magnetization current density of ${}_{}{}^{87}{}_{}{}^{}\mathrm{Sr}$ have been measured. The results are used to determined the shape of the radial wave function of the valence neutron shell. The experiment yields a rms radius of $1g_{\frac{9}{2}}$ neutrons that is 0.31 ± 0.04 fm smaller than predicted by density-dependent Hartree-Fock theory.

Angular distributions of evaporation residues from the (${}_{}{}^7{}_{}{}^{}\mathrm{Li}, \alpha$) reaction on ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$, ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$, and ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$ have been measured as a function of excitation energy in the compound nuclei ${}_{}{}^{200}{}_{}{}^{}\mathrm{Hg}$, ${}_{}{}^{235}{}_{}{}^{}\mathrm{Pa}$, and ${}_{}{}^{239}{}_{}{}^{}\mathrm{Np}$. Evaporation-residue probabilities $P_{\mathrm{ER}}=\frac{\sigma ({}_{}{}^7{}_{}{}^{}\mathrm{Li}, \alpha xn)}{\sigma ({}_{}{}^7{}_{}{}^{}\mathrm{Li}, \alpha )}$ are obtained. These give the first microscopic information on $\frac{{\Gamma }_n}{{\Gamma }_f}$ at 12 to 20 MeV excitation, which is independent of the compound-nucleus formation cross section. The results are compared with expectations based on previous systematic values of $\frac{{\Gamma }_n}{{\Gamma }_f}$.

The elastic differential cross section of 7.0-GeV/c ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ scattered from hydrogen (equivalent $T_p=1.05\mathrm{}$ GeV) has been measured over a range $0.17<~-t<~0.85$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The experiment has very low background (≤2%), adequate $t$ resolution (≤5%), a good absolute normalization (15%), and a statistical accuracy in the interference region of about 3%. The data show a shallow first minimum and a shape very similar to the recent data from Centres d'Etudes Nucléaires de Saclay.

New 1.029-GeV $p$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ data and new 1.05-GeV data are in excellent agreement with multiple-diffraction-theory predictions. The theoretical calculations include spin and isospin dependence of the $\Delta$-intermediate-state process and show that it fills the first diffraction minimum. The recently normalized data from Centre d'Etudes Nucléaires de Saclay and the older data from Brookhaven National Laboratory disagree with our calculations and the new data.

The polarization in $p$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ elastic scattering has been measured between 0.56 and 1.73 GeV in a range of the square of the four-momentum transfer between 0.006 and 1.2 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The data are characterized by positive polarization maxima at $-t$ near 0.08 and 0.36 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. At 0.56 GeV, a sharp peak of large negative polarization at 0.23 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ is observed. This structure persists at higher bombarding energies, but is no longer negative and becomes increasingly shallower as the bombarding energy increases to 1 GeV and then is relatively unchanging.

Measurements of the $2{}_{}{}^3{}_{}{}^{}P-4\mathrm{}{}_{}{}^3{}_{}{}^{}D$, $4{}_{}{}^3{}_{}{}^{}F$ transitions of neutral helium are carried out in a turbulent linear discharge plasma. The profiles indicate the existence of high-frequency fields generated by plasma instabilities that interact with atoms immersed in the plasma and give rise to quadratic Stark shifts of the allowed line and to second- and fourth-order plasma satellite transitions. A quantitative evaluation of these features indicates the existence of severe inconsistencies in present theoretical calculations.

A new theory of the optical glory is given. The results are in good agreement with the exact Mie solution. The physical effects responsible for the glory are explained.

A new mechanism is presented for anomalous dc resistivity when the electron drift velocity is close to the electron thermal velocity and $T_e\gg T_i$. The turbulent plasma can break up into homogeneous essentially field-free regions (of width $\gtrsim 60{\lambda }_{\mathrm{D}e}$)) separated by ion density spikes ($\delta n_i\simeq n_1$) and potential jumps ($\frac{e\Delta \varphi }{\mathrm{kT}}>~1$) (double layers). dc resistivity results from the thermalization via an electron-electron two-stream instability of the energy gained by electrons accelerated over a potential jump. No runaway electrons are produced in this process.

A new class of structures is predicted to exist for monolayer films on solid surfaces. These structures involve two incommensurate lattices—the monolayer lattice and the surface lattice— which have a preferred relative orientation. The precise orientation depends upon the lattice constant and symmetry of each lattice. We believe this orientationally ordered incommensurate phase to be present in many physisorbed films. In particular, the existence of this phase appears to explain recent low-energy electron diffraction data for rare gases adsorbed homogeneous substrates.

Experimental evidence has been obtained, by the ion-beam channeling technique, that an osmium atom introduced into beryllium metal occupies positions displaced from a regular substitutional lattice site. The anomalous displacement is found to persist after annealing to a temperature above that at which impurity diffusion occurs. Of the several heavy-metal impurities in beryllium which have been previously studied, osmium is unique in this respect.

There are forty-five simple binary suboctet non-transition-metal compounds $A^N{B}^{P-N}$ ($3<~P<~6$) which crystallize in six crystal structures belonging to two broad families. We show that although these structures cannot be differentiated using isotropic atomic coordinates, successful topological separation is achieved using anisotropic bond-charge coordinates with $\mathrm{sigma}$ and $\pi$ symmetry. Anisotropic bond-charge coordinates were previously used by St. John and Bloch to separate the five structures of 59 compounds of the prototypical $A^N{B}^{8-N}$ octet family.

We show that the transient temperature response of a freely suspended sample to heat impulses and to heat pulses of varying duration may be interpreted to yield values of the thermal-boundary (Kapitza) resistance to heat flow into He I and He II. Our results show that in He II the thermal flux is carried by first and second sound, each of which has a characteristic kapitza resistance.

A neutron-scattering study of the ferroelectric transition in Cs${\mathrm{D}}_2$P${\mathrm{O}}_4$ has yielded quasi-elastic diffuse distributions of intensity typical of a one-dimensional system with chain-like ordering parallel to the ferroelectric $b$ axis of this monoclinic crystal. Therefore, despite such suggestive similarities as the large isotope shift in $T_c$, the transition is quite different from that of tetragonal K${\mathrm{D}}_2$P${\mathrm{O}}_4$ where the diffuse scattering clearly exhibits characteristics of three-dimensional dipolar interactions.

On the basis of the excitation-induced absorption spectra insilver halides doped with impurities, two kinds of shallow electron centers are identified. One is an electron bound at a silver interstitial ion and corresponds to the intrinsic electron center in silver halides. Addition of chalcogen impurities enhances the spectra of this origin. The other is an electron bound at substitutional divalent cations, the transition energy of which shifts systematically depending on the kind of impurity.

We report the structure and electronic properties of ${\left(\mathrm{SN}{\mathrm{Br}}_{0.4}\right)}_x$ and the first chemical modification of the polymeric superconductor ${\left(\mathrm{SN}\right)}_x$. Its dc conductivity at 300 K is ten times greater than that for ${\left(\mathrm{SN}\right)}_x$ and the thermoelectric power is positive rather than negative. The plasma energy and the superconductivity transition temperature are essentially unchanged. These results suggest that a small displacement of the Fermi level and a large increase in scattering time occur upon bromination.