The recent communication by Garcia and Pearson, of the same title as this note, is examined and shown to contain an error. The conclusions drawn by Garcia and Pearson are therefore incorrect.

Correlation measurements have resulted in an unambiguous $\frac{9}{2}$ spin assignment to the level in ${\mathrm{F}}^{19}$ at 2797 keV. The lifetime of this level has been measured with the Doppler shift attenuation method to be 246±44 fsec, which establishes its positive parity assignment.

The far-infrared background due to a superposition of infrared galaxies of the type recently observed is computed. It is shown that these galaxies contribute an amount of energy to the universe roughly equal to that radiated by the other galaxies and produce a far-infrared background peaking beyond 50 μ. It is likely that they account for most of the observed extragalactic radio background but not the 3°K microwave background.

The Stanford Linear Accelerator Center 40-in. hydrogen bubble chamber has been exposed to positron-electron annihilation radiation at 5 and 7.5 GeV, which was superimposed upon a background of bremsstrahlung radiation with 12-GeV maximum energy. Reaction cross sections for events with no neutral particles are presented for all energies up to 12 GeV, for one neutral at 5 and 7.5 GeV, and for multineutral production at 7.5 GeV.

The total hadronic $\gamma p$ cross section has been measured using 7.5-GeV positron-electron annihilation radiation in a hydrogen bubble chamber. A value of 126 ± 17 μb is found, excluding reactions with only one charged particle (∼3 μb).

We have investigated the mass spectra of the systems recoiling against peripherally produced ${\Delta }^{++}$ for the reactions $\mathrm{pp}\to {\Delta }^{++}p{\pi }^{-}$, $\mathrm{pp}\to {\Delta }^{++}p{\pi }^{-}{\pi }^0$, and $\mathrm{pp}\to {\Delta }^{++}n{\pi }^{+}{\pi }^{-}$ at 6.6 GeV/c. The experimental cross-section ratios of these systems are found to be comparable with the known on-mass-shell cross section ratios $\sigma ({\pi }^{-}p\to {\pi }^{-}p):\sigma ({\pi }^{-}p\to {\pi }^{-}p{\pi }^0):\sigma ({\pi }^{-}p\to {\pi }^{-}n{\pi }^{+})$ as a function of mass of the system $m\lesssim 1.8$ GeV. This result is compatible with a one-pion-exchange interpretation for the production of the peripheral ${\Delta }^{++}$ component in these five-body states and furthermore suggests that $\pi \pi$ and $K\pi$ inelastic scattering may be realistically studied in the same way.

It is shown that for any local tensor field $f_{\mu \nu }\mathrm{}\left(x\right)\mathrm{}$ with certain natural properties, the space integral of $f_{0\nu }$ is proportional to the energy-momentum operator $P_{\nu }$. General conditions are established under which the agreement of a charge operator with the space integral of a local density on the one-particle subspaces implies their agreement on all of Hilbert space.

The renormalization of the $K_{e3\mathrm{}}$ form factor by the strong SU(3)-nonconserving interaction is calculated from the Fubini-Furlan sum rule and an experimental determination of the derivative of the matrix element of the divergence of the strangeness-changing current. The calculated renormalization is in agreement with that determined from measurements of $\mathrm{ft}$ values in Fermi nuclear $\beta$ transitions and of the absolute rate for $K^{+}\to e^{+}{\pi }^0\nu$.

The validity of the vector-dominance model has been tested by ${\rho }^0$ pion production at 4 GeV and ${\pi }^{+}$ photoproduction data. In the forward direction, a remarkable agreement has been observed with the photoproduction data, down to $t_{min}$. ${\rho }^0$ pion production in the backward direction shows good agreement through this model with available photoproduction data in the $u$ channel. A comparison is made with theoretical work on $\Delta$-Regge trajectory exchange.

Acoustic paramagnetic resonance was observed in arsenic-doped germanium. The $g$ factor and the temperature and magnetic-field orientation dependence of the acoustic absorption coefficient were measured. The spin-lattice relaxation rate was estimated and compared with electron spin resonance values.

Measurements of the proton-proton bremsstrahlung cross section $\frac{d\sigma }{d{\Omega }_{1}d{\Omega }_2}$ at 99 MeV are reported. Cross sections of 3.77±0.23, 5.14±0.22, 9.01±0.33, and 18.83±1.15 μb/${\mathrm{sr}}^2$ were obtained at angles of 25°, 30°, 35°, and 40°, respectively. The angular distributions of the photons were determined kinematically. The results agree generally but not in detail with theoretical predictions.

Time-reversal invariance for strong interactions, in particular for that part of the force which flips the spin of the proton, has been tested by comparing the polarization and asymmetry in the elastic scattering of 32.9-MeV protons from ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ at 60°. By making the measurements for ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ relative to ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, where spin flip is forbidden except in case of parity nonconservation, we avoid the need to measure either an absolute beam polarization or absolute analyzing power. Our first result is that the polarization and asymmetry are equal to ±2.5%; consequently, we observe no violation of time-reversal invariance.

With a schematic model for the nuclear matter we give a unified treatment of the real and imaginary parts of the elastic ${\mathrm{O}}^{16}$-${\mathrm{O}}^{16}$ scattering potential. The model connects the parameters of the potential with the density and binding properties of the ${\mathrm{O}}^{16}$-${\mathrm{O}}^{16}$ system and reproduces the structure of the excitation function quite well. It is shown that the nuclear compressibility can be obtained from the scattering data, and in the case of the ${\mathrm{S}}^{32}$ compound system there results an effective compressibility (finite quenching of the nuclei) of about 200 MeV.

The shift of pulsar frequencies due to the general-relativistic corrections to the optical path of photons in the field of the sun is discussed. Remarks concerning its detection are added.

We present partial cross sections for $K^{+}d$ and isospin-0 $\mathrm{KN}$ scattering around 1 BeV/c.

We have observed a resonance in the ${\pi }^{-}{\pi }^{+}$ final state with $I=0\mathrm{}$, $M=1.06\mathrm{}\pm 0.015$ GeV, and $\Gamma <0.07\mathrm{}$ GeV; our analysis favors $l>~2$. It is produced primarily at a four-momentum transfer squared less than 0.1 Ge${\mathrm{V}}^2$, and observed most clearly in the region where the cosine of the $\pi \pi$ scattering angle is less than -0.75.

Including nuclear disintegration due to the pion absorption and the effect of the nuclear excited states, the nuclear Adler-Weisberger sum rule is shown to be valid satisfying the Goldberger-Treiman relation.

Effects due to the $D$-wave component of the deuteron wave function in high-energy proton-deuteron scattering are investigated. Although negligible for most values of momentum transfer, they are quite significant in the "dip" region where the $S$-wave single-and double-scattering contributions interfere destructively. Here the $D$-wave contributions are large enough to fill in the dip, turning it into a shoulder, without the need for phase variation or spin dependence in the nucleon-nucleon amplitudes.

In connection with our recent studies of one-boson-exchange potentials we have related our higher order regularized Yukawa functions to the nucleon-meson form factor. The adaptation of this form factor to a massless vector-meson field leads to an electromagnetic form factor. The corresponding electrostatic potential follows immediately as a special case. We pursue a special example which leads to a very good fit to data.

We have measured the yield of electron-positron pairs from the reaction $\gamma +\mathrm{C}\to e^{+}+e^{-}+\mathrm{C}$ as a test of the validity of quantum electrodynamics at very small distances. Our results show that first-order quantum electrodynamics correctly predicts the $e^{+}{e}^{-}$ pair yield up to an invariant pair mass of 900 MeV/${\mathit{c}}^2$.