We have measured neutron-proton elastic-scattering cross sections for the range $0.15\lesssim -t\lesssim 3.6$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The logarithmic slope parameter is found to be consistent with existing proton-proton parametrizations. The data also exhibit a dip in the cross section near $-t\approx 1.4$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ for incident neutron momenta above 200 GeV/c. Differences between $n-p$ and $p-p$ cross sections are noted in the region $0.7\lesssim -t\lesssim 1.4$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$.

We predict a new source of jet structure in $e^{+}{e}^{-}$ colliding-beam experiments arising from photon-photon collisions. These jets are produced with a sizable fraction of the total observable hadronic rate and have unmistakable signatures. Observations of these jets would provide important tests of the contributions of three classes of hard-scattering mechanisms: quark exchange in $\gamma \gamma \to q\overline{q}$, gluon exchange in $\mathrm{qq}$ and $q\overline{q}$ scattering, and constituent-interchange processes with a characteristic ${p_{\perp }}^{-6\mathrm{}}$ behavior.

We have measured in a single experimental setup the differential cross sections and polarizations of the $Y^{*}\mathrm{}\left(1385\right)\mathrm{}$ produced in the two line-reversed reactions ${\pi }^{+}p\to K^{+}{Y}^{*}\mathrm{}\left(1385\right)\mathrm{}$ (260 eV/μb) and $K^{-}p\to {\pi }^{-}{Y}^{*}\mathrm{}\left(1385\right)\mathrm{}$ (180 eV/μb) at 11.5 GeV/c. We compare these results to ${\Sigma }^{+}$ production in the same experiment. The data have been derived from a triggered bubble-chamber experiment using the SLAC Hybrid Facility. We find that both helicity-flip-dominated ($Y^{*}$) and helicity-nonflip-dominated ($\Sigma$) processes are consistent with weak-exchange-degeneracy predictions.

Inclusive cross sections are presented for $2\pi$ and $3\pi$ systems with large longitudinal $x$ at the highest intersecting storage ring energies ($\sqrt{s}=53\mathrm{}$ GeV for $2\pi$; $\sqrt{s}=53\mathrm{} \mathrm{and} 62$ GeV for $3\pi$). The ratio $\frac{{\pi }^{+}{\pi }^{-}}{{\pi }^{-}{\pi }^{-}}$ rises sharply with increasing $x$ similar to the ratio $\frac{K^{+}}{K^{-}}$, as expected in a quark-model interpretation.

We present proton-nucleus dimuon-production cross sections for masses between 4 and 15 GeV, center-of-mass rapidities between -0.23 and 0.6 and incident energies of 200, 300, and 400 GeV. The data confirm scaling to the 20% level. The dependence of continuum $〈p_T〉$ on beam energy is also presented.

The average $\gamma$-ray multiplicity $M$ has been measured as a function of the scattering angle, energy loss, and nuclear charge of the projectile fragment produced in the ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$-${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$-${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$ reactions at a bombarding energy of 5.99 MeV/N. $M$ increases steeply as a function of energy loss for the partly damped collisions but remains nearly constant for the fully damped events. $M$ appears to depend mainly on energy loss rather than on mass transfer. The results are discussed in terms of a classical sticking model for the reaction mechanism.

The angular-momentum dissipation in deeply inelastic heavy-ion collisions is described as a transport process. Using transport coefficients which have been evaluated within a single-particle model, mean value and variance of the intrinsic angular momenta of the fragments are calculated. The fluctuations become important already for initial relative angular momenta $l\lesssim \frac{1}{2}{l}_{\mathrm{grazing}}$. Excellent agreement with $\gamma$-multiplicity data for the reaction ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$(5.99 MeV/nucleon) + ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$ is obtained.

We investigate the effect of particle resonances on low-frequency magnetohydrodynamic modes in field-reversed geometries, e.g., an ion ring. It is shown that, for sufficiently high field reversal, modes which are hydromagnetically stable can be driven unstable by ion resonances. The stabilizing effect of a toroidal magnetic field is discussed.

Results of a first-principles renormalization-group calculation of the three-dimensional critical interface in a gravitational field are presented. No artificial cutoffs to prevent divergences are required. A detailed comparison with reflectivity measurements of Wu and Webb is included.

Very general symmetry considerations uniquely favor a bcc crystal structure near the melting line. This agrees with observations that almost all metals on the left-hand side of the periodic table are bcc at high temperature, and that, even where other structures are more stable, the first phase nucleated on rapid cooling can be bcc. Furthermore, icosahedral local symmetries are favored in amorphous solids. Fluctuation effects cause the transition from isotropic liquid to crystal to be first order in any dimension.

For isotropic three-dimensional ferromagnets, neutron-scattering and hyperfine-interaction experiments yield 2.5 and 2.0, respectively, for the dynamical critical exponent $z$. This apparent contradiction is removed by two hypotheses. (1) The effective value of $z$ depends on the wave-vector region sampled, and for small $q$ approaches $z=2.0\mathrm{}$. (2) Hyperfine-interaction experiments are asymptotic in $q$, while present neutron-scattering experiments are not.

Accurate measurements of de Haas-van Alphen effect amplitudes in mercury show, for the first time, departures from quasiparticle behavior. The departures arise from the influence of the electron-phonon interaction.

We test the conjecture that convoy electrons emitted from solid targets originate from electrons bound in the potential wake trailing the traversing ion. Although we observe distinct differences in the longitudinal velocity distribution between solid and gaseous targets, we do not observe the predicted $Z_1$, velocity, and target-material dependences. From this we conclude that the majority of convoy electrons from solids do not originate from wake-bound electrons.

Using a special infrared scanning technique we have produced photographs of the electron-hole-droplet cloud in unstressed Ge. Contrary to past beliefs, the cloud of droplets resulting from focused-laser surface excitation in neither spherical, hemispherical, nor cylindrically symmetric about the excitation point. The observed concentration of droplets along certain crystal-symmetry axes provides compelling evidence for a phonon wind which pushes droplets into the sample.

We report studies of the temperature dependence of the Knight shift of Cu atoms near to Cr atoms in dilute $\mathrm{Cu}\mathrm{Cr}$ alloys. Comparison with $\mathrm{Cu}\mathrm{Mn}$ and $\mathrm{Cu}\mathrm{Fe}$ leads us to propose electronic structures for these important systems. We confirm the general picture of Hirst: The atoms have integral numbers of $3d$ electrons and obey Russell-Sanders coupling, but the sign of the crystal field is opposite to that of Hirst, and Fe has seven rather than six $3d$ electrons.

An example is given of an admissible configuration of SU(3) gauge fields that completely screens an intense source of color and that has a lower energy than the corresponding Coulomb configuration.

We construct exact monopole and dyon solutions in a renormalizable $\mathrm{SU}\mathrm{}(N+1\mathrm{})\mathrm{}$ gauge theory broken down to $\mathrm{SU}\mathrm{}\left(N\right)\mathrm{}\otimes \mathrm{U}\mathrm{}\left(1\right)\mathrm{}$ by one Higgs multiplet in the adjoint representation. The solutions saturate the Bogomolny lower bound and are spherically symmetric with respect to the angular momentum operator $\overrightarrow{\mathrm{J}}=-i\overrightarrow{\mathrm{r}}\times \nabla +\overrightarrow{\mathrm{T}}$, where $\overrightarrow{\mathrm{T}}$ spans the maximal SO(3) subalgebra of $\mathrm{SU}\mathrm{}(N+1\mathrm{})\mathrm{}$. The solutions are obtained after a remarkable factorization of the relevant coupled nonlinear second-order radial equations into a product of coupled linear first-order equations.

The possibility of a zero-mass up or down quark, in broken chiral symmetry, is shown to be in serious contradiction with the nonrenormalization theorem.

We have measured the polarization of 3×${10;}^6$ ${\Lambda }^0$ and 2.5×${10}^5$ ${\overline{\Lambda }}^0$ hyperons produced by 400-GeV protons on a beryllium target. The hyperons were detected at a fixed angle of 7.2 mrad and in the momentum range from 50 to 300 GeV/c for ${\Lambda }^0$ and 50 to 200 GeV/c for ${\Lambda }^0$. The ${\Lambda }^0$ polarization agrees with that measured at 24 and 300 GeV and is - 0.24 ± 0.04 at $p_T=2.1\mathrm{}$ GeV/c. The ${\overline{\Lambda }}^0$ polarization is zero up to $p_T=1.2\mathrm{}$ GeV/c.

We have analyzed in the leading-logarithm approximation a closed set of equations, the solution of which describes correctly the processes $e^{+}+e^{-}\to \mathrm{anything}$, $e+h\to e+\mathrm{anything}$, and $e^{+}+e^{-}\to h+\mathrm{anything}$. This approach allows us to justify clearly the application of the renormalization group and the so-called factorization property. Since the technique is basically a skeleton expansion, it should be useful to give a unified description of all jet processes.