Extended coupled channels calculations have been performed for neutron elastic and inelastic cross sections and analyzing powers for vibrational nuclei with $40<A<\mathrm{}208\mathrm{}$ to determine the sensitivity of these observables to the coupling to isoscalar giant resonances. The calculations concentrated on the neutron energy region between 10 and 17 MeV, and the 10 MeV results for ${}_{}{}^{116,120}{}_{}{}^{}\mathrm{Sn}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ and 12 MeV results for ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ are illustrated here.

NUCLEAR REACTIONS ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{116,120}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ ($n, n$) and ($n, n^{\prime }$); sensitivity of $\sigma \left(\theta \right)$ and $A_y\left(\theta \right)$ near 10 MeV to isoscalar giant resonances; extended coupled channels calculations.

Deuteron spectra from the ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$, ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}$, ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}({}_{}{}^3{}_{}{}^{}\mathrm{He}, d)$ reactions at an incident energy of 130 MeV (43.3 MeV/nucleon) have been measured in an angular range ${\theta }_{\mathrm{lab}}=7.5\mathrm{}°-21\mathrm{}° \mathrm{in}$ 1.5° steps. Target mass and angular dependences of the centroid energy $E_c$, the full width at half maximum $\Gamma$, and the differential cross sections of the breakup peak are presented. The width of the peripheral region where the breakup process is assumed to take place has been estimated to be about 0.7 fm.

NUCLEAR REACTIONS $X({}_{}{}^3{}_{}{}^{}\mathrm{He}, d)$, $X={}_{}{}^{47}{}_{}{}^{}\mathrm{Al}, {}_{}{}^{59}{}_{}{}^{}\mathrm{Co}, {}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}, {}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$; $E=130\mathrm{}$ MeV; measured $\frac{d^2\sigma (\epsilon , \theta )}{d\epsilon d\Omega }$; deduced $\frac{d\sigma \left(\theta \right)}{d{\Omega }_{\mathrm{lab}}}$, $\Gamma \left(\mathrm{FWHM}\right)$, centroid energy $E_c$, and the total cross section ${\sigma }_{\mathrm{bu}}$ of the breakup peak.

($\alpha$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) and ($\alpha , t$) continuum inclusive spectra are measured on target nuclei ranging from ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ to ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$. Systematic differences in the absolute magnitudes of the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and triton spectra are found. To explain these differences the distorted-wave Born approximation calculations in the post form for inclusive breakup reactions are performed. It is shown that Coulomb effects are responsible for these differences.

NUCLEAR REACTIONS ($\alpha , t$), ($\alpha$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) breakup reactions: measured $\frac{d^2\sigma }{d\Omega \mathrm{dE}}$; targets: ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$; post form DWBA breakup theory.

A wide range of experiments has been conducted in order to obtain the neutron capture gamma ray spectrum for the low capture cross section nucleus ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$. Analysis of the results revealed a $Q$ value of 4604.58 ± 0.14 keV which subsequently permitted the determination of several low-lying level energies to be established with an average precision of 0.2 keV. The absolute intensity for the observed transitions was found and essentially all the primary strength was assigned. Because the cross section can be accounted for by $s$-wave neutron capture and since the spins of many low-lying levels are known, multipolarity assignments could be made. Analysis indicated the electric quadrupole strength to be higher than expected.

NUCLEAR REACTIONS ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}(n, \gamma )$; thermal; measured $I_{\gamma }$, $E_{\gamma }$; deduced $Q_n$, level energies.

The high-energy thermal neutron capture $\gamma$ rays in ${}_{}{}^{165}{}_{}{}^{}\mathrm{Dy}$ have been studied. Analysis has revealed 15 new levels below an excitation energy of 1650 keV in addition to 14 that were previously reported. The spins of the newly observed levels are most likely ½ or $\frac{3}{2}$.

NUCLEAR REACTIONS ${}_{}{}^{164}{}_{}{}^{}\mathrm{Dy}(n, y){}_{}{}^{165}{}_{}{}^{}\mathrm{Dy}$; thermal; measured $E_{\gamma }$; identified levels.

We have studied the dependence of the pion-deuteron total cross section on the range of the off-shell pion-nucleon amplitude, using a relativistic three-body theory which has as input the six $S$- and $P$-wave pion-nucleon channels and the two $S$-wave nucleon-nucleon channels, but which does not include the effect of pion absorption. We found that in order to fit the total cross section data in the region of the 3,3 resonance, we need a form factor with a range in momentum space of about 1 GeV/c.

NUCLEAR REACTIONS Pion-deuteron scattering; $E=50-350\mathrm{}$ MeV; calculated ${\sigma }_{\mathrm{TOT}}$.

Neutron-pair exchange and alpha exchange between two identical colliding cores, ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ in the first case and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ in the second case, are correctly described by a generalized Frahn and Venter parametrization of the elastic scattering phase shift. Possibility of a Josephson effect is discussed.

NUCLEAR REACTIONS Elastic scattering ${}_{}{}^{34}{}_{}{}^{}\mathrm{S}$(${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$,${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$) and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$(${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$,${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$); $E_{{}_{}{}^{32}{}_{}{}^{}\mathrm{S}}=77-97\mathrm{}$ MeV; ${\theta }_{\mathrm{cm}}=30\mathrm{}°-150\mathrm{}°$, $\Delta \theta =1\mathrm{}°$; generalized phase shift analysis: particle exchange between identical cores.

As an addendum to a previous paper we report on four-boson binding energy calculations which use separable expansions only for the (3 + 1)-subsystem amplitudes. In contrast to the previous procedure, the amplitudes of the (2 + 2) subsystems are now incorporated exactly, according to the four-body formulation of Haberzettl and Sandhas, with the help of a convolution method. Our investigation clearly shows the feasibility of such a treatment.

NUCLEAR STRUCTURE Four-body bound state calculations. Separable two-body forces. Separable expansion of (3 + 1)-subsystem amplitudes. Exact treatment of (2 + 2)-subsystem amplitudes.

Variations after angular momentum projection for the $0^{+}$,...,${10}^{+}$ ($K=0\mathrm{}$) levels of the ground-state band and the excited prolate band in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ yield almost rotational extensions of both experimental bands, and a crossing of the oblate and prolate bands that should occur between the $8^{+}$ and ${10}^{+}$ levels. The band assignments of some recently observed levels are discussed.

NUCLEAR STRUCTURE ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$; variation after $0^{+}$,...,${10}^{+}$ projection for oblate and prolate bands.

The addition of a new ($1^{-}$,0) level at 29 MeV excitation energy in ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ to the level spectrum of Fiarman and Meyerhof leads to a calculated ${}_{}{}^4{}_{}{}^{}\mathrm{He}(\gamma , p)$ to ${}_{}{}^4{}_{}{}^{}\mathrm{He}(\gamma , n)$ cross section ratio of 1.67. The calculated ratio falls within the experimental range of 1.6-1.9 without utilizing charge-symmetry violating forces.

NUCLEAR REACTIONS ${}_{}{}^4{}_{}{}^{}\mathrm{He}(\gamma , p)$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}(\gamma , n)$. Calculated the ratio of ($\gamma , p$) to ($\gamma , n$) cross sections at the GDR peak to be 1.67.

A recent "elementary particle" treatment of positron longitudinal polarization in allowed nuclear $\beta$ decay by Holstein is extended to include neglected induced scalar and pseudoscalar contributions. The effect of these additional terms on two precision polarization experiments suggested as tests of the conserved vector current, second class currents, and Fierz interference, while small, is not negligible and complicates the interpretation of results. Recoil order effects in proposed polarization tests of parity-symmetric theory are described.

RADIOACTIVITY Extended calculation of longitudinal ${\beta }^{+}$ polarization in allowed decay.

Recently Zwarts et al. presented data on the forward-backward asymmetry in the particle decay of giant resonances which they interpret as being due to interference with direct knockout processes. In discussing the interference problem we show that the presented features of an asymmetry beginning at the effective particle threshold and increasing with excitation energy are not characteristic for this interference but are expected to arise even in the absence of any resonance decay.

NUCLEAR REACTIONS ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}(\alpha , {\alpha }^{\prime }{\alpha }_0)$, $E_{\alpha }=155\mathrm{}$ MeV; measured $\alpha -{\alpha }_0$ angular correlations; deduced giant resonance decay. Interference of sequential decay and knockout processes.

We discuss theories leading to the intermediate state $N\Delta$ and $\Delta \Delta$ contributions to $V_{\mathrm{NN}}$. We focus on the customary addition of ${\mathcal{L}}_{\Delta N\pi }^{\prime }$ to ${\mathcal{L}}_{\pi \mathrm{NN}}^{\prime }$ in a conventional field theory and argue that overcounting of contributions to $t_{\pi N}$ and $V_{\mathrm{NN}}$ will be the rule.

NUCLEAR STRUCTURE Nucleon-nucleon interaction, noniterative $2\pi$ exchange, $N\Delta$, $\Delta \Delta$ intermediate states.

It is pointed out that the Urbana, Stony Brook, and Bonn groups treat the $\Delta$-isobar contributions to the $\mathrm{NN}$ interaction in different ways, which lead to different conclusions regarding the overcounting problem. It is questioned whether, in a field-theoretic framework neglecting quark-theoretic viewpoints, the $\pi N$ system, in general, and the Chew-Low model, in particular, can serve as reliable testing grounds for boson-exchange models of the $\mathrm{NN}$ interaction.

NUCLEAR STRUCTURE $\mathrm{NN}$ interaction, $\Delta$ isobars, $\pi N$ system.

We show that the introduction of a ${\mathrm{U}}^{B+F}\mathrm{}\left(6\right)\mathrm{}$ group into the multi-$j$ supersymmetric scheme permits a better agreement with the energy spectrum of ${}_{}{}^{195}{}_{}{}^{}\mathrm{Pt}$ and suggest two other possible supersymmetric classifications.

NUCLEAR STRUCTURE Interacting boson-fermion model; multi-$j$ supersymmetric scheme.

It is proposed that the transfer of two neutrons explains the relative enhancement in the subbarrier fusion cross section of ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ + ${}_{}{}^{65}{}_{}{}^{}\mathrm{Ni}$ with respect to ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ + ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$. Similar relative enhancements in other cases of low energy heavy-ion fusion reactions are noted.

NUCLEAR REACTIONS Fusion, enhancement of sub-Coulomb heavy-ion fusion rates by transfer reactions.

We report observations of inelastic interactions of uranium nuclei with energies up to ∼ 1 GeV/nucleon in nuclear emulsions exposed on the occasion of the first successful acceleration of relativistic uranium ions. About one-half of the interactions lead to binary fission. With increasing primary energy, the relative frequency of violent nuclear interactions increases at the expense of binary fissions. Also reported is a range measurement of uranium nuclei in emulsion at 0.945 GeV/nucleon.

NUCLEAR REACTIONS Emulsion exp., ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ at $\frac{E}{A}<~1$ GeV/nucleon. Energy dependences of mean free path length and frequencies of event topologies. Range measurements.

Data for the analyzing power $A_y\left(\theta \right)$ for the elastic scattering of neutrons from deuterons have been measured at 14.1 MeV for the range from 30° to 153° (c.m.) to accuracies between ±0.003 and ±0.006. The results are compared to previous $n-d$ data at 14 MeV and are in significant disagreement with the most recent measurement. The present data are in excellent agreement with a Faddeev calculation by Doleschall. The data are also very similar to $p-d$ scattering data at 14.1 MeV, although systematic deviations are observed at forward angles and near the maximum of $A_y\left(\theta \right)$ at 130°. Recent calculations indicate that Coulomb effects can explain most of these differences, although some features will require further investigation.

NUCLEAR REACTIONS ${}_{}{}^2{}_{}{}^{}\mathrm{H}(\overrightarrow{n}, n){}_{}{}^2{}_{}{}^{}\mathrm{H}$, $E=14.1\mathrm{}$ MeV; measured $A_y\left(\theta \right)$, compared to ${}_{}{}^2{}_{}{}^{}\mathrm{H}(\overrightarrow{p}, p){}_{}{}^2{}_{}{}^{}\mathrm{H}$, compared to Faddeev calculations.