By projecting $s$-channel partial waves from a $t$-channel Regge trajectory, families of resonances obeying $l\sim \sqrt{s}$ are obtained. It is proposed that these are Regge trajectories obeying $\alpha \sim \sqrt{s}$ for high $s$.

We have searched for isospin-2 hyperon resonances produced in $K^{-}n$ interactions at 2.11 and 2.65 GeV/c which decay into ${\Sigma }^{-}{\pi }^{-}$ or ${\Sigma }^{-}{\pi }^{-}{\pi }^0$. We find no evidence for any such state with $M<~2300$ MeV, and obtain a cross-section upper limit of 30 μb, with 99% confidence level.

Generalized dispersion sum rules are used for determining the $A_2$ trajectory and residue function in pion photoproduction. Our results favor the Gell-Mann mechanism of ghost elimination for the $A_2$ over the Chew and no-compensation mechanisms.

A possible zero at the wrong-signature sense point ${\alpha }_{\Delta }=\frac{1}{2}$ on the exchanged ${\Delta }_{\delta }$ trajectory is suggested in connection with the new Cornell-Brookhaven National Laboratory experiments on the ${\pi }^{-}p$ backward peaks.

An analysis is made of the effects of spin dependence in proton-deuteron and protonhelium scattering. Using spin-dependent amplitudes consistent with experiments we are able to simultaneously fit both $p-\alpha$ and $p-D$ scattering. The above result may constitute a test for Regge cuts in the $N-N$ scattering amplitude.

We report measurements of the differential cross sections of ${\rho }^0$- and $\varphi$-meson photo-production on hydrogen for a range of the square of the four-momentum transfer $t$ from -0.2 to -0.9 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ and a range of incident photon energies from 6.5 to 17.8 GeV. We find that differential cross sections obtained for ${\rho }^0$ production are in good agreement with the vector-dominance model.

Rotational excitation and de-excitation $J_f-J_i=\pm 2$, $J_i=0,\cdots ,3\mathrm{}$, of ${\mathrm{H}}_2$ by slow electrons with and without the simultaneous excitation of one vibrational quantum has been measured. The absolute total cross section for pure rotational excitation $J=3\mathrm{}\leftarrow 1$ in the energy range 1-10 eV is presented. The measurements of angular dependences indicate $s$-, $p$-, and $d$-wave scattering.

We present measurements of the change in the velocity of sound in liquid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ on the addition of small quantities of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ for three compositions and three frequencies. It is shown that the change is not strictly linear in ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ concentration and that the nonlinearity may be explained to a large extent if corrections to the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ effective mass, which arise from the many-body interactions, are included.

We present a theory of transport in strong magnetic fields which is not limited to linear response in the electric field. The steady-state occupation probabilities of the eigenstates of the crossed-field Hamiltonian are determined by a master equation and are shown to be independent of the absolute coupling constants to the scattering system, but dependent on the form of the interaction. A generalized orbit-jump formula is derived for the dissipative current.

The ${\mathrm{He}}^3$ melting pressure to 17 mdeg K and the change in molar volume on melting to 30 mdeg K have been measured. These, along with the slope of the melting curve, are presented and compared with other results.

The temperature dependence of the elastic moduli and ultrasonic attenuations of plutonium is not consistent with the antiferromagnetism hypothesis for this metal at low temperatures. The elastic and anelastic behavior of plutonium indicates the possible existence of a cooperative electron transition at 66°K.

The generalized magnetic susceptibilities, $\chi \left(\overrightarrow{\mathrm{q}}\right)$, have been calculated along the line $\Gamma$ to $A$ for the heavy rare-earth metals, Gd, Dy, Er, and Lu, using energy bands previously calculated by Keeton and Loucks. The initial ordering periodicity for each of these metals can be related to Fermi-surface geometry by examining the maxima in our susceptibilities. Agreement with experimental magnetic wave vectors is satisfactory.

A simple approach to lattice dynamics provides a treatment of noninstantaneous (dispersive) anharmonicities in highly anharmonic crystals with singular (hard-core) interparticle potentials. The theory may be used to study the balance between single-particle and collective motions (phonons) in solid helium.

The shape-dependent parameters $P$ and $Q$ of the effective-range expansion for the $S$-wave $p-p$ interaction have been obtained from experimental data between 0 and 10 MeV, including recent results at 6.141, 8.097, and 9.918 MeV. The preferred best values are $P=0.072\mathrm{}\pm 0.005$ and $Q=0.034\mathrm{}\pm 0.004$.

We consider high-energy reactions on deuterium that are selective to one type of nucleons. The strong suppression at small momentum transfers of cross sections for two identical nucleons in the final state is shown to be strongly dependent on the spin nature of the reaction. Recent data on ${\pi }^{+}$ photoproduction on deuterium are reproduced.

An experiment to test time-reversal invariance by the principle of detailed balance in the reaction ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}(d,\alpha ){}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ and its inverse has been performed. The experiment shows that detailed balance is satisfied with an uncertainty of ±0.5%.

The pionic three-body potential in nuclear matter is shown to be comparable with the two-body potential.

The magnetic hyperfine splitting for rotational levels of deformed, even-even nuclei in muonic atoms is shown to result in an asymmetric $\gamma$-ray doublet, whose center of gravity is in general shifted towards lower energies. This pseudoisomer shift is of the order of magnitude of the reported "isomer" shifts.

The energy shifts of the nuclear gamma rays from the first rotational states of ${\mathrm{Nd}}^{150}$, ${\mathrm{Sm}}^{152}$, ${\mathrm{Gd}}^{154}$, ${\mathrm{Er}}^{166}$, ${\mathrm{W}}^{182}$, ${\mathrm{W}}^{184}$, and ${\mathrm{W}}^{186}$ due to the presence of a muon in a $1s$ state have been measured. The shifts are related to changes in the nuclear mean-square charge radius, and are compared with Mössbauer isomer-effect measurements.