A study of the reaction ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p, \gamma ){}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ has been performed using a polarized proton beam. The results show that $E2\mathrm{}$ and $M1\mathrm{}$ radiations are significant in the giant-dipole-resonance region of ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$. The measured analyzing power is combined with cross-section measurements to obtain $J^{\pi }$ values and both relative strengths and phases of the $T$-matrix elements.

Limits of > ${10}^5$ astronomical units are set on the decay length of an electron antineutrino ${\overline{\nu }}_e$ via the process ${\overline{\nu }}_e\to {\nu }^{\prime }+\gamma$ for $E_{\gamma }$ in the range 0.1-0.5 MeV using the results from a well-shielded detector in the vicinity of a fission reactor. This mode of decay is therefore ruled out as a possible explanation for the paucity of solar neutrinos revealed by the experiment of Davis.

The requirement of compatibility of vector-meson dominance and partial conservation of axial-vector current in ${\pi }^0\to 2\gamma$ decay [along with $\mathrm{SU}{\mathrm{}\left(6\right)\mathrm{}}_W$ symmetry] determines the absolute value of the $\rho \pi \pi$ coupling constant. The strength of strong interactions results inversely proportional to the number of postulated quarks. In dynamical models of spontaneous symmetry breaking the electromagnetic, weak, and gravitational interactions are found also to have strengths inversely proportional to the corresponding numbers of fundamental fermions.

An explicit relationship between the dispersion relations of collective modes and the energy spectrum of turbulent fluctuations is derived from a sum-rule analysis of the dielectric response function. It is pointed out that turbulence produces significant modification in the despersion relation so that an experimental investigation of such an effect offers a promising method of probing a turbulent plasma.

We have observed cyclotron resonance of electrons in an inversion layer on a (100) surface of $p$-type Si. The effective mass ${m_c}^{*}$ is found to be about $0.21m_0$, compared with a bulk value of $0.1905m_0$. The surface mass value decreases slightly with increasing gate voltage.

Cyclotron resonance in the $n$-type inversion layer of silicon has been observed at 4.2°K for electron densities between (0.38 and 9.0) × ${10}^{12}$/${\mathrm{cm}}^2$. The electron mass is $m^{*}=(0.20\mathrm{}\pm 0.01)m_0$ and independent of electron density. The far-infrared mobility decreases monotonically as the electron density increases, in marked contrast to the dc mobility which exhibits a strong maximum in the same range of electron concentrations.

A new effect in insulated-gate field-effect transistors is predicted: the appearence of an anisotropic transverse voltage generated perpendicular to the conducting channel. The transverse voltage is shown to be very sensitive to the surface sub-band mobility anisotropies and sub-band energy positions. The effect suggests a new and powerful diagnostic tool for the study of the physics of the semiconductor surface.

Measurements on the polarized-proton capture reaction ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}(p, {\gamma }_0){}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ indicate a broad $E2\mathrm{}$ resonance which lies above the giant $E1\mathrm{}$ resonance of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. The measurements show that the $E2\mathrm{}$ radiation for the ($\gamma , p_0$) channel of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ exhausts approximately 30% of the quadrupole sum rule.

Differential cross sections for electron scattering from hydrogen and deuterium in the deep-inelastic region show that the neutron cross section is significantly smaller than the proton cross section over a large part of the kinematic region studied. Although $\nu {W_2}^d$ differs in magnitude from $\nu {W_2}^p$, it exhibits a similar scaling behavior.

Pion diffraction dissociation into masses up to approximately 6 GeV is observed in the reaction ${\pi }^{-}+p\to p+X$ at 205 GeV/c. The pion single-diffraction cross section for mass squared ≤ 32 Ge${\mathrm{V}}^2$ is 1.9 ± 0.2 mb.

The dependence of the neutrino total cross section ${\sigma }_{\nu }$ on neutrino energy has been measured up to 160 GeV. The data are consistent with a linear dependence with slope (0.58 ± 0.25) × ${10}^{-38\mathrm{}}$ ${\mathrm{cm}}^2$/GeV. The ratio of the antineutrino to the neutrino total cross section $\frac{{\sigma }_{\overline{\nu }}}{{\sigma }_{\nu }}$ has been found to be approximately constant up to 70 GeV at a value which is consistent with the numerical value of $\frac{1}{3}$ expected for the scattering of neutrinos and antineutrinos by relativistic pointlike spin-½ fermions.

Ab initio quantum-mechanical calculations have been carried out for the pair and triplet potential energies of hydrogen molecules in order to check the pairwise additivity assumption in interpreting the shock experiments of van Thiel et al. It is shown that this assumption fails at distances less than 4.5 bohr. An effective pair potential obtained from the present calculations compares favorably with experimentally determined pair potentials at 3.5 bohr or larger. At shorter distances, it shows the presence of higherorder many-body forces.

We describe a new and experimentally verified model of gas laser excitation by relativistic electron beams. It is shown that in the pressure range 1-50 Torr ${\mathrm{N}}_2$, nearly all the excitation of the 3371-Å nitrogen laser is caused by low-energy plasma electrons (and not by primary or cascade electrons).

A novel method of automodulating an intense relativistic electron beam has been demonstrated. The modulation is accomplished by passing the electron beam through a series of cavities that are inserted into a conventional drift tube. Experimental results indicate that the current is modulated at a frequency of 500 MHz at a relative modulation amplitude exceeding 80%.

Measurements of the current transported when an intense, relativistic electron beam penetrates a low-pressure gas show that the net current exceeds the primary beam current. As the pressure is increased, a gradual transition to conditions of magnetic neutralization is observed. Computations of the trajectories of secondary electrons in partially neutralized, uniform beams suggest that secondary electron drift may be responsible for the current amplification.

The spatial saturation and the frequency dependence of the energy spectrum of ionacoustic waves in a low-pressure discharge in helium in the pressure range 0.03-0.2 Torr has been investigated. In the high-pressure region the spectrum is peaked around the most unstable frequency predicted by linear theory [i.e., ${\omega }_{\mathrm{Peak}}\sim \left(\frac{1}{\sqrt{3}}\right){\omega }_i$], and the wave energy saturates at the modest value of $\frac{W}{n{T}_e}\simeq {10}^{-5\mathrm{}}$. At low pressures the wave energy increases and varies with frequency according to $W\left(\omega \right)\propto {\omega }^{-\alpha }$, with $\alpha$ assuming values between 2.2 and 2.8.

We have observed that the intensity fluctuations of light scattered from solutions of hemoglobin contain a term independent of the scattering vector. We have interpreted these fluctuations as arising from the hemoglobin association-dissociation reaction. In support of this interpretation we find that variations in these fluctuations with solution conditions agree with the known variations in the reaction.

We report the dielectric constants of $p$, $p^{\prime }$-di-$n$-heptyl azoxybenzene in the nematic and in the smectic-$A$ phase. Around the nematic-smectic transition ${\epsilon }_{\parallel }$ decreases with decreasing temperature while ${\epsilon }_{\perp }$ increases anomalously. This is explained by an increased dipolar correlation between the molecules due to the formation of the smectic planes.

We have measured the detailed temperature dependence of the cholesteric pitch in cholesteryl nonanoate near the smectic-$A$ transition. The data show a power-law behavior with an exponent $\nu =0.675\mathrm{}\pm 0.025$, in agreement with theoretical prediction and with elastic-constant measurements in nematics.

The nuclear acoustic resonance of ${\mathrm{He}}^3$ spins has been excited and detected via Rayleigh waves on a metal surface. The signal is many orders of magnitude larger than the nuclear acoustic resonance signal detected in the bulk of solids. Its magnitude is very sensitive to surface damage. The effect has been observed with liquid ${\mathrm{He}}^3$ in contact with gallium, aluminum, and gold.