A relativistic three-body theory previously used to generate the $\omega$ has been applied to the $1^{+}$ state of three pions. An $A_1$ resonance pole is produced with $M_{A_1}=1160\mathrm{}$ MeV, $\frac{\Gamma }{2}=90\mathrm{}$ MeV, but there is no associated phase variation of the amplitude.

In a study of the reaction $e^{+}{e}^{-}\to \gamma \gamma$ in the region of the $\psi \mathrm{}\left(3684\right)\mathrm{}$ resonance, no evidence is found for a deviation from quantum electrodynamics. Limits are also set on the decays $\psi \mathrm{}\left(3684\right)\mathrm{}\to {\pi }^0\gamma$, $\psi \mathrm{}\left(3684\right)\mathrm{}\to {\eta }^0\gamma$, and $\psi \mathrm{}\left(3684\right)\mathrm{}\to X^0\gamma$, where $X^0$ is a pseudoscalar state in the mass range 2500-3000 MeV which subsequently decays into two $\gamma$ rays.

It is shown that it is possible to measure the total angular momentum of proton hole states by means of the ($t, \alpha$) reaction using a recently developed polarized triton source. The reactions ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}(t, \alpha ){}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}(t, \alpha ){}_{}{}^{207}{}_{}{}^{}\mathrm{Tl}$ have been studied at 17-MeV bombarding energies and show large differences in the analyzing powers between spin-orbit partners $p_{\frac{1}{2}}$ and $p_{\frac{3}{2}}$ in the former case and $d_{\frac{3}{2}}$ and $d_{\frac{5}{2}}$ in the latter case. It is concluded that measurement of asymmetries in ($t, \alpha$) reactions is a powerful technique to assign both $l$ and $j$ transfers for proton-pickup reactions.

The cross sections for the reaction (${\pi }^{+}, {\pi }^0$) on ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$, and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ were measured over the energy range of 70 to 250 MeV by activation methods. The excitation functions were found to be flat with cross sections of about 2.5 mb for ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, 0.4 mb for ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$, and 1.0 mb for ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$.

The reactions ${}_{}{}^7{}_{}{}^{}\mathrm{Li}({\pi }^{+}, {\pi }^0){}_{}{}^7{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}({\pi }^{+}, {\pi }^{-}){}_{}{}^{10}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}({\pi }^{+}, {\pi }^0){}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ are examined using a full multiple-scattering formalism with a separable form assumed for the pion-nucleon $t$ matrix. Spin-flip contributions are included. We find that the contributions arising from transitions to nonanalog final states in the case of ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ and ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ are of the same order of magnitude as pure analog cross sections.

Up to now no experimentally feasible method for detecting abnormal nuclear states has been known. We propose to observe them in high-energy heavy-ion collisions through the disappearance of, or irregularities in, high-density nuclear Mach shock phenomena.

We have used the phenomenon of laser-induced molecular photodissociation to determine the homogeneous linewidth at 2 K of the origin (zero-phonon line) and a vibronic transition in the mixed-crystal absorption spectrum of dimethyl $s$-tetrazine in durene. From the measured 55-MHz (upper limit) homogeneous width of the origin we conclude that in the vibrationless excited state coherence persists at least during the 6-nsec lifetime. The 29-GHz homogeneous vibronic linewidth is ascribed to vibrational relaxation.

We examine the parametric coupling of the negative-energy drift-cone mode near the ion-cyclotron frequency with lower-frequency positive-energy modes through the electronic nonlinearity. This parametric process is shown to be stabilized by azimuthal asymmetry occurring in the early stage of the buildup. The theory is compared with the experimental observations.

The surface resonance peak is a prominent feature in the photoelectron spectrum of the clean W(100) surface when $hv=16.8\mathrm{}$ eV, but is not observed when $hv=26.9\mathrm{}$ eV. This indicates that the intensity of this peak is critically dependent upon the $\overrightarrow{\mathrm{p}}·\overrightarrow{\mathrm{A}}$ matrix element, which should be large for photon energies below the tungsten plasmon energy of 23 eV, but small for photon energies above it. The consequences of this on the nature of the surface resonance are discussed.

We present a general differential cross section, in the colliding-beam rest frame, for $\mu e$-pair production by leptonic decays of a heavy spin-½ lepton pair, themselves assumed to be produced via one-quantum annihilation. Our results hold for general $V$, $A$, $S$, $T$, $P$ couplings and depend neither on the $\mu e$-universality assumption nor on the absence or presence of neutral-current effects. We also present distributions relevant to the events reported by a Lawrence Berkeley Laboratory-Stanford Linear Accelerator Center group.

We show that the suppression of color-brightening effects in leptoproduction is a general property of a class of spontaneously broken color-gauge theories, based on integer-charge quarks.

Analogs of giant-dipole-resonance states have been excited in ${}_{}{}^{27}{}_{}{}^{}\mathrm{Mg}$ via the ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}(n, p){}_{}{}^{27}{}_{}{}^{}\mathrm{Mg}$ reaction using 56.1-MeV neutrons. This reaction is restricted to $\Delta T=1\mathrm{}$ transitions and thus provides a unique way of studying the $T_{>}$ components of the giant dipole resonances. A comparison with photonuclear and ($p, p^{\prime }$) spectra is made in an attempt to separate $T_{>}$ from $T_{<}$ components and $E1\mathrm{}$ from the overlapping $E2\mathrm{}$ isoscalar resonances.

Quasifission reactions induced by 443-MeV ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ ions on ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ are studied and compared with results at 365 MeV. The initial relative motion is completely damped in both cases. At the higher energy, the angular distribution is broader and peaked further forward, and the complete-fusion component is larger. Near the grazing angle partially damped events are observed in addition to quasifission.

A surface approximation to the multistep amplitude for direct reactions is presented. Within this approximation, the distorted-wave Born-approximation series is summed in closed form, and the result is tested by comparing with exact coupled-reaction-channels calculations for ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}(p, d, p){}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}(d, p, d){}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. The approximation gives a good representation of the exact results, especially for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}(d, p, d){}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ process which is dominated by strong absorption of the deuteron.

A procedure is described for extracting the pole position of a resonant amplitude from a knowledge of the phase shift versus energy. Pole positions are determined for the four $p$-wave resonances in the nucleon-$\alpha$ system with high precision. The use of the pole position to define the mass of unstable nuclear states is discussed.

We have investigated, via a $1-\frac{2}{2}$ dimensional computer simulation, the possibility of forcing an initially isotropic, magnetized plasma into an anisotropic state by means of an external pump. Strong heating of the perpendicular ion temperature was observed together with a strong cooling of the longitudinal temperature. This mechanism could enhance particle trapping in tokamaks and increase confinement time in mirror machines. We use basic physical arguments to predict the maximum temperature ratio that can be obtained.

We investigate the stability of long-wavelength, plane-polarized electromagnetic waves when the oscillatory energy of the electrons exceeds their rest energy. The strong electron-mass variation destabilizes electron modes polarized along the electric field of the pump ${\overrightarrow{\mathrm{E}}}_0$. The electron and ion modes decouple in the presence of such an intense pump and hence the ions do not strongly influence the instability.

The long-term absorption and scattering of light obliquely incident on an inhomogeneous and self-consistent evolving plasma profile including differential ion flow is considered. In general, the plasma has a sharp rise in density from subcritical to supercritical. The subcritical density decreases for increasing radiation pressure relative to the plasma pressure. In this profile an instability develops of the radiating decay type which modulates and generally enhances the absorption. The plasma density profile appears to evolve toward large light absorption.

We report a new method of measuring thermal-equilibrium properties of vacancies in metals through current-noise measurements. Aluminum noise spectra taken at 435 and 475°C directly yield vacancy lifetimes ${\tau }_0=4.7\mathrm{}\times {10}^{-3\mathrm{}} \mathrm{and} 2.8\times {10}^{-3\mathrm{}}$ sec, respectively, corresponding to a migration energy $E_m=0.6\mathrm{}$ eV, and permit estimation of a unit vacancy resistivity $\Delta {\rho }_v=1.9\mathrm{}\times {10}^{-8\mathrm{}}$ Ωm/at.% from the measured product ${\left(\Delta {\rho }_v\right)}^2{\eta }_v$, ${\eta }_v$ being the vacancy concentration taken from literature data.

The power spectra of fluctuations in the mean square of the Johnson-noise voltage across small semiconductor and metal films in thermal equilibrium were measured down to ${10}^{-4\mathrm{}}$ Hz. The spectra have a $\frac{1}{f}$-like behavior that matches the resistance-fluctuation spectra obtained by passing a current through the samples. These measurements contribute strong evidence that $\frac{1}{f}$ noise is due to equilibrium resistance fluctuations.