A mountaintop measurement of the microwave background at $\lambda =3.3\mathrm{}$ mm gives a thermodynamic radiation temperature of (${2.46}_{-0.44\mathrm{}}^{+0.40\mathrm{}}$)°K. This result is consistent with a temperature of 2.7°K, obtained at longer wavelengths, and the postulate of a blackbody spectrum.

We suggest that a dip at $t=-3\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ which appears in both ${\pi }^{+}p$ and ${\pi }^{-}p$ scattering over a wide range of laboratory momentum is related to the dips in the 180-deg cross sections at 2.1 GeV/c. The energy dependence of the cross sections in the vicinity of the dip is consistent with a Regge trajectory for which $\alpha =-2\mathrm{}$ at $t=-3\mathrm{}$.

A very simple model is suggested for the recently reported pulsed radio sources based on the vibrational (rather than compressional) modes of a star.

The photon energy spectrum from the reaction ${\pi }^{-}+d\to 2n+\gamma$ at zero energy has been measured by a pair spectrometer using accoustic spark chambers to locate the pair-electron tracks. From the shape of the spectrum the neutron-neutron scattering length was determined to be $a_{\mathrm{nn}}={13.1}_{+2.4\mathrm{}}^{-3.4\mathrm{}}$. The probability of existence of a bound state of two neutrons was calculated to be less than 5 × ${10}^{-9\mathrm{}}$.

The study of the finite-energy sum rules for $\mathrm{KN}$ scattering indicates that the $A_2$ trajectory chooses the no-compensation mechanism at ${\alpha }_{A_2}\mathrm{}\left(t\right)\mathrm{}\approx 0$.

The technique of Bjorken is combined with the Ward identities for the time-ordered products of currents to obtain a correlation between space-space equal-time commutators and the high-energy behavior of the hadron proper functions. The method is illustrated for the three-point function of conserved isovector currents.

We have investigated the photoproduction process $\gamma +p\to {\pi }^{+}+n$ over a wide range of energies and $u$ values at the Stanford Linear Accelerator Center (SLAC) accelerator. We also have investigated $\gamma +p\to {\pi }^{-}+N^{*++}$ at one value of $u$ and $\gamma +p\to K^{+}+{\Lambda }^0$, ${\Sigma }^0$ at one $u$ value and three energies. Our results for $\frac{d\sigma }{\mathrm{du}}$ for the photoproduction of ${\pi }^{+}$ mesons from hydrogen are roughly $\frac{\alpha }{2\pi }$ of the corresponding cross sections for the elastic scattering of ${\pi }^{-}$ mesons from hydrogen. The $u$ dependence of our cross sections is not dominated by nucleon exchange as it is in the case of ${\pi }^{+}p$ elastic scattering.

Measurements of the ratio ($R$) of positron-proton and electron-proton elastic-scattering cross sections have been made, with the square of the four-momentum transfer ($q^2$) equal to 0.20, 0.69, 0.73, 1.54, 2.44, 3.27, 3.79, and 5.00 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The measurements, after radiative corrections, are consistent with $R=1\mathrm{}$, with standard errors ranging from ±0.016 to ±0.123. The results give limits for the size of the two-photon effects.

We have studied a sample of 144 ${\tau }^{\prime }$ decays in which, for the first time, all the kinematical quantities are determined. The dependence of the matrix element on the neutralpion energy has been measured and a linear extrapolation has been made to zero four-momentum. The result is consistent with the soft-pion prediction of current algebra.

It is pointed out that the existence of a strangeness-zero, neutral, vector boson with mass $O\left(30\mathrm{} \mathrm{GeV}\right)$ and strong coupling to muons is consistent with the recent experimental results on the anomalous magnetic moment of the muon, the direct production of high-energy muons in cosmic rays, and the observations of multiple-core cosmic-ray events with high momentum transfers. A discussion is given in which two feasible experiments are mentioned that could test the model.

A dynamical model based on supercnvergence equations and Regge asymptotics generates parallel daughter trajectories for positive and negative $t$. The results are found by studying different reactions both by means of sum rules and the partial-wave analysis of Regge terms proposed by Schmid.

New dispersion sum rules for cross sections, coupling constants, and low-energy scattering data are derived by considering modified forward-scattering amplitudes. A set of these sum rules, which involve highly convergent integrals, may be useful for testing low-energy phase-shift analyses of $\pi \pi$ and $\mathrm{KN}$ scattering.

We have studied the time distributions of 242 leptonic decays of neutral $K$ mesons produced in the reaction $K^{-}+p\to {\overline{K}}^0+n$. For the $\Delta S=-\Delta Q$ parameter $x$ we find $\mathrm{Re}\mathrm{}\left(x\right)={0.22}_{-0.09\mathrm{}}^{+0.07\mathrm{}}$, $\mathrm{Im}\mathrm{}\left(x\right)=-0.88\mathrm{}\pm 0.08$.

The decay rate and the energy asymmetry of the $\eta$ particle observed in the strong decay $\chi \to \eta +2\mathrm{}\pi$ are discussed in the context of SU(3) ⊗ SU(3) chiral dynamic Lagrangian.

A Zeeman-quenching atomic-beam method has been developed and used for the determinations of the energies and lifetimes of the metastable autoionizing $\mathrm{}\left(1s2s2p\right)\mathrm{}{}_{}{}^4{}_{}{}^{}P$ states of ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$. The values obtained for certain of these parameters are in serious disagreement with existing theoretical estimates. The energy values have been used for the definitive identification of previously unassigned lines in the Li spectrum.

A new magnetic resonance method has been developed for studying the metastable autoionizing states previously observed in the alkali elements. With this technique, two distinct but nearly degenerate metastable states were discovered in potassium: a $\left(3\mathrm{}{p}^{5}4s3d\right){}_{}{}^4{}_{}{}^{}F_{\frac{9}{2}}^{}{}_{}{}^{}$ state and a $\left(3\mathrm{}{p}^{5}4s4p\right){}_{}{}^4{}_{}{}^{}D_{\frac{7}{2}}^{}{}_{}{}^{}$ state. In addition, a value of $Q=(5.3\mathrm{}\pm 0.8)\times {10}^{-26\mathrm{}}$ ${\mathrm{cm}}^2$ (uncorrected for the Sternheimer effect) has been obtained for the ${\mathrm{K}}^{39}$ nucleus. The production of polarized electrons and nuclei from these states is also discussed.

The cyclotron and spin resonance of free electrons field confined in a small volume in ultrahigh vacuum have been observed via the rapid loss of electrons when their cyclotron motion is excited by the rf field and spin-dependent collision processes with polarized Na atoms in a beam, respectively. The electrons were polarized by spin exchange and then monitored through the spin dependence of the excitation process $e+\mathrm{Na}\mathrm{}\left(3S\right)\mathrm{}\to e+{\mathrm{Na}}^{*}\mathrm{}\left(3P\right)\mathrm{}$ and hence of their cooling rate.

From observations on large, single, liquid crystals it has been found that nematic $p$-azoxyanisole exists in two distinct forms: One rotates the plane of polarization of transmitted light clockwise and the other, counterclockwise by the same amount, in analogy to the right- and left-handed forms of quartz, revealing a significant feature of the structure of nematic liquids which has not previously been reported.

Oscillations of electrostatic fields present when electrons are strongly heated by electron-beam plasma interaction reveal large-amplitude oscillations with $\frac{\omega }{k_{\parallel }}\lesssim v_b$, the electron-beam speed; $\omega \approx \frac{{\omega }_{\mathrm{ce}}}{10}$, where ${\omega }_{\mathrm{ce}}$ is the electron gyrofrequency; coherence lengths of roughly a few wavelengths (« plasma length); and maximum electrostatic potential in the wave approaching the applied beam voltage. A gross compatibility is found between the observed frequencies and wavelengths and the predictions of a linear theory.

The absorption cross section for transitions from the $F$-center ground state to the conduction band has been calculated for KCl. The absorption bands $L_1$, $L_2$, $L_3$, and $L_4$ are easily identified in the cross section and a new band $L_5$ has been calculated.