We have searched for production of charmed mesons in the reaction ${\pi }^{-}+N\to D^{*-}+X$, $D^{*-}\to {\pi }^{-}+{\overline{D}}^0$, ${\overline{D}}^0\to K^{+}+{\pi }^{-}$ at a beam momentum of 10.5 GeV/c. We measure the cross section times branching ratio to be 7±20 nb/nucleon.

Measurements of inclusive cross sections at 100 GeV/c are presented for the double-charge-exchange reactions $a^{+}p\to {\pi }^{-}X$ with $a=\pi , K, or p$. The measurements covered a kinematic range in the Feynman $x$ variable of $0.3<~x<~0.9$ at transverse momenta of 0.3 and 0.5 GeV/c. A model summing the contributions from resonance production and from inclusive central-region ${\pi }^{-}$ production is used to fit the data and demonstrates the importance of resonance production via one-pion exchange for large values of the Feynman $x$.

We present upper limits on the production of heavy leptons ($L^{\pm }$) by neutrinos via the process ${\nu }_{\mu }+\mathrm{Ne}\to L^{\pm }+\cdots$, $L^{\pm }\to e^{\pm }+\nu +\overline{\nu }$. These limits imply that the $L^{-}$ and $L^{+}$, if they couple in full strength to ${\nu }_{\mu }$, are heavier than 7.5 and 9 GeV, respectively. They also imply that the coupling strength ${\nu }_{\mu }$ to the recently discovered 1.9-GeV heavy lepton $\tau$ is less than 0.025 of the normal ${\nu }_{\mu }-\mu$ coupling.

The Lorentz invariance of the gauge-invariant Green's functions in the local quantum field theory of electric and magnetic monopoles is formally established. This is accomplished by expressing these Green's functions as functional integrals over the trajectories of classical charged particles.

High-spin states in ${}_{}{}^{164}{}_{}{}^{}\mathrm{Er}$ have been populated by the reaction ${}_{}{}^{150}{}_{}{}^{}\mathrm{Nd}({}_{}{}^{18}{}_{}{}^{}\mathrm{O}, 4n){}_{}{}^{164}{}_{}{}^{}\mathrm{Er}$. In addition to the lowest even-spin superband we present the first evidence for the lowest odd-spin and the second lowest even-spin superbands. We also observe the first example of the intersection of the $\gamma$-vibrational band with these superbands. The rotation-alignment model can explain the observed pattern of behavior.

Ericson fluctuations of the triton and helium-3 decays of the compound nucleus ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$ formed in the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ reaction have been studied for excitation energies between 33 and 38 MeV. These mirror channels are only weakly correlated which is partly attributed to an isospin-nonconserving width of about 20 keV.

Characteristic $\gamma$ radiation produced in the reaction ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(K^{-}, {\pi }^{-}\gamma )$ at a kaon momentum of 1.7 GeV/c has been analyzed with Ge(Li) detectors. A transition at 789±4 keV is a candidate for a new hypernuclear $\gamma$-ray line. The intensity of this transition corresponds to a c.m. forward-angle production cross section of 48±12 μb for the reaction ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(K^{-}, {\pi }^{-}\gamma )$. Several $\gamma$-ray lines observed with ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, Be, B, C, and O targets could be ascribed to ordinary nuclear transitions.

A marked difference between analyzing powers for reactions ${}_{}{}^{128}{}_{}{}^{}\mathrm{Te}(p, t){}_{}{}^{126}{}_{}{}^{}\mathrm{Te}\left({2_1}^{+}\right)$ and ${}_{}{}^{110}{}_{}{}^{}\mathrm{Pd}(p, t){}_{}{}^{108}{}_{}{}^{}\mathrm{Pd}\left({2_1}^{+}\right)$ with polarized protons has been observed, while the ground-state transitions have shown similar analyzing powers. The difference is accounted for as a result of a phase change of the interference between direct and inelastic multistep processes in two-neutron pickup reactions. The origin of this phase change is elucidated on the basis of the microscope description of the collective quadrupole oscillation of nuclei.

A $p-\gamma$ coincidence experiment has been performed with 400-MeV protons. The angular and momentum analysis of the scattered proton demonstrates a primary quasifree process. The residual nuclei which have been identified from the $\gamma$-ray spectra characterize the final states and indicate an evaporation process or a sequential ejection at low energy of some correlated nucleons. In addition, preliminary results with triple coincidences ($2p-\gamma$) indicate a promising way to clarify the mechanism of quasifree reactions.

${}_{}{}^{196}{}_{}{}^{}\mathrm{Pt}$ has been investigated with numerous ($n, \gamma$) techniques. The structure of the low-spin positive-parity states below the pairing gap shows excellent agreement with the predictions of the O(6) limit of the interacting boson approximation model of Arima and Iachello.

Prominent $\gamma$-ray reference lines including ${}_{}{}^{198}{}_{}{}^{}\mathrm{Au}$ 411 and 675 keV and ${}_{}{}^{192}{}_{}{}^{}\mathrm{Ir}$ 205, 295, 308, 316, 468, 484, 588, 604, and 612 keV have been measured with respect to an ${\mathrm{I}}_2$-stabilized He-Ne laser. The ${}_{}{}^{198}{}_{}{}^{}\mathrm{Au}$ 411-keV line, a de facto $\gamma$-ray standard, is reported at 3.0107788 pm (0.37 ppm) or 411 804.41 eV, which is 25 ppm higher in energy and forty times more accurate than previous values.

Molecular ions, which define the initial separation between nuclei, are used as a probe of the potential established by swift ions in solids. Employing 75-300-keV ${\mathrm{H}}_2^{+}$ and He${\mathrm{H}}^{+}$ ions one observes that a large fraction of clusters do not explode in solid targets whose thickness is much greater than the mean electron-loss distance. The results are consistent with the view that protons moving in solids carry bound electrons.

We report the observation of doubly excited autoionizing Rydberg states of Sr, belonging to the configuration $5p_{\frac{1}{2}}$, $\mathrm{nl}$. Our procedure involves a three-step optical excitation process which incorporates Stark switching to reach higher $l$ states not normally accessible because of dipole selection rules. Quantum defects are reported for several $5p_{\frac{1}{2}}$, $\mathrm{ns}$ and $5p_{\frac{1}{2}}$, $\mathrm{nd}$ states. The lifetimes of the $5p_{\frac{1}{2}}$, $\mathrm{ns}$ states are shown to scale as ${\left(n^{*}\right)}^3$, and the lifetimes of the $5p_{\frac{1}{2}}$, $16l$ states are shown to increase dramatically with increasing $l$.

A new predissociation in ${\mathrm{H}}_2$ has been studied by simultaneous observation of the absorption spectrum in the 850-805-Å region together with the Ly-$\alpha$ excitation spectrum. From the observed variations of the dissociation probability with $v$ and $N$, the mechanisms of the predissociation are inferred.

Interferometric data resolved to 1 μm and 15 psec confirm the significant role of radiation pressure during high-intensity laser-plasma interactions. Specifically observed manifestations include electron density profiles steepened to ∼1-μm scale length, clearly defined upper and lower density shelves, and small- and large-scale deformations of transverse isodensity of surfaces.

The He-LiF selective-adsorption data of Frankl and co-workers are analyzed using an attractive-well, corrugated-wall model. The model is solved to convergence by an expansion method. The calculated He-LiF spectrum is in good agreement with experiment. Calculations show that the intensity of weakly bound states is enhanced by band splitting with stronger resonances. This may provide a method for observing these states.

A reinterpretation of the ir spectra of Dean and Henry in oxygen-doped GaP strongly suggests that they involve radiative capture and excitation of the second electron bound to oxygen. Further, this electron is localized near the nearest-neighbor Ga ions, it is bound by ∼0.9 eV as found also by Samuelson and Monemar, and its electron-phonon coupling is small—$\lambda \approx 0.6$, $\hslash \omega \approx 47.5$ meV—in disagreement with Henry et al. The analysis emphasizes the usefulness of the "phonon signature" in identifying deep levels from their optical spectra.

The resistivity of liquid Lu, which has been measured for the first time up to 1800°C, has a negative temperature coefficient. In the framework of structural-disorder scattering this means that $2k_{\mathrm{F}}$, the diameter of the Fermi sphere of conduction electrons, lies close to the wave number $K_p$ of the first peak of the structure factor. This is consistent with recent band-structure calculations by Duthie and Pettifor providing good evidence that the number of $s$ electrons per atom changes from about 0.5 for La to 1.5 for Lu.

Transient photoconductivity has been used to measure the electron drift mobility in the $c^{\prime }$ direction of single-crystal naphtalene from 54 to 324 K. Below 100 K the mobility rises exponentially with decreasing temperature, an effect which we attribute to the onset of band-type motion limited by optical-phonon scattering. This observation allows the identification of the approximately constant mobility at higher temperatures ($T>\mathrm{}100\mathrm{}$ K) with the hopping of localized charge carriers.

The production of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ in coincidence with a heavy fragment has been studied with a solid-state telescope and a gas telescope. For heavy fragments detected at 36° and 42°, we have mapped coincident emission of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ from 80° to 320° in the reaction plane. We find evidence for $\alpha$ evaporation from both fragments and for a significant number of pre-equilibrium ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ particles at c.m. angles near to 90° from the detected heavy fragment with average c.m. energy of ≈ 30 MeV.