The β- and γ-decay rates, electron scattering form factors, and intermediate energy (p,p’) and (p,n) cross-section data from select transitions in ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ are analyzed to test 0p shell-model predictions of M1 components of the spin-flip transition densities, and to quantitatively assess magnetic dipole quenching.

The influence of both quantal and thermal fluctuations on the level-density parameter a in hot nuclei is investigated. It is found that the large-amplitude motion of the nuclear surface has little influence on a and that the observed temperature and angular momentum behavior is properly explained through the thermal properties of the energy-dependent effective mass.

We present the invariant mass and transverse momentum dependence of direct electron-positron pair production in p-Be collisions at a beam kinetic energy of 4.9 GeV. The acceptance of our apparatus is shown to have no significant effect for masses above 0.15 GeV. After a correction is made for the available phase space, the transverse momentum dependence of the data is found to be comparable to hadron-hadron observations. A phenomenological calculation involving ${\pi }^{+}$${\pi }^{\mathrm{-}}$ annihilation into $e^{+}$$e^{\mathrm{-}}$ is shown to be in good agreement with our measurements.

The ${}_{}{}^3{}_{}{}^{}\mathrm{H}$(d→,γ${)}^5$He reaction observables σ(θ), $A_y$(θ), and $A_{\mathrm{yy}}$(θ) have been measured at seven angles with a 400 keV incident deuteron beam which was stopped in a tritiated titanium target. The data have been fit using a transition matrix element analysis. This analysis indicates that the cross section is primarily channel spin S=(3/2 E1 radiation, with approximately 2.5% S=(1/2 E1 radiation and 2.5% M1 radiation.

Data from ${}_{}{}^{204}{}_{}{}^{}\mathrm{Pb}$(p,p’${)}^{204}$Pb conversion-electron and gamma-ray experiments, together with previous results, prove the existence of two levels ($0^{+}$ and $2^{+}$) at 1583-keV excitation energy in ${}_{}{}^{204}{}_{}{}^{}\mathrm{Pb}$. Modified values (limits) of the ${\rho }_{21}^2$ and $X_{211}$ are 0.0013<${\rho }_{21}^2$<0.015 and $X_{211}$>0.073. New experimental evidence indicates that all the three observed excited $O^{+}$ states in ${}_{}{}^{204}{}_{}{}^{}\mathrm{Pb}$ can be explained as belonging to the four-neutron-hole valence space and, therefore, there is no clear candidate for the proton 2p-2h intruder state in this nucleus.

We have used an axially symmetric deformed Thomas-Fermi model to evaluate the fission barrier of ${}_{}{}^{240}{}_{}{}^{}\mathrm{Pu}$ as a function of the quadrupole moment $Q_2$ for different values of the angular momentum L and temperature T. The fission stability diagram of this nucleus is investigated.

The bound states and resonances of a two-particle system occur at the complex energies for which the system’s T matrix has poles. Presented is a more efficient method of computing these energies for symmetric potential interactions.

Attention is drawn to the strong collective L=4 direct excitation of the state at 2.367 MeV in ${}_{}{}^{100}{}_{}{}^{}\mathrm{Ru}$ by inelastic scattering of 16 MeV protons characterized by a deformation parameter ${\beta }_4$=0.10, one of the highest reported for any region of the mass table.

The occurrence of multiple parity doublets, enhanced E1 transitions between parity-doublet levels, characteristic decoupling parameters for K=(1/2 parity-doublet bands, and hybridization of the nuclear magnetic moments are sought as evidence for reflection asymmetric shape in odd-Z odd-mass rare-earth nuclei. Specific results consistent with such an assumption are presented for the nucleus ${}_{{}_{61}{}^{151}{}_{}{}^{}}{}^{}{}_{}{}^{}\mathrm{Pm}_{90}^{}{}_{}{}^{}$. Suggestions are offered for further experiments following a review of available information on other nuclei of the region.

The possibility of a low-energy octupole resonance in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ which exhausts a significant fraction of the energy-weighted isoscalar sum rule is investigated in a distorted-wave-Born-approximation–random-phase-approximation model. It is found that the ∼15% sum-rule fraction, seen recently in low-energy (p,p’) reactions, depends sensitively on the strength of the isovector projectile-target nucleon interaction.

The distorted wave impulse approximation is used for an analysis of experimental data of the ${}_{}{}^6{}_{}{}^{}(\mathit{p}$,pd${)}^4$He reaction measured at 8 and 9 MeV. Potential coupling and kinematic coupling approximations for the description of the final state were examined. The effects of spin-dependent distortions are also studied. Satisfactory agreement between the experimental results and the calculations is achieved only when potential coupling approximation is used and spin-orbit distortions are included.

The coupled-channel model is compared to new, accurate measurements of the deuteron elastic electric structure function. The fit to previous elastic form-factor data is also shown because of small modifications arising from correcting the sign of a tensor term in the NN to ΔΔ coupling potential. The improved fits give preference to the Gari-Krümpelmann nucleon electromagnetic form factors and also to the radius of asymptotic freedom of quarks corresponding to the cloudy bag model. The sensitivity of the choice of radius of asymptotic freedom to the result of the analysis of recent $T_{20}$ data remains high.

We have analyzed the anomalous nuclear enhancement in inclusive spectra at large transverse momentum in high-energy proton-nucleus collisions. It is shown that the rearrangement of the constituent nucleons may give rise to such an enhancement.

The angular distributions of cross section and analyzing power for the radiative capture reaction ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$(p→,${\gamma }_0$${)}^{16}$O have been measured at excitation energies of 35.0 and 39.0 MeV in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. Gamma rays were detected in a large, self-shielded NaI spectrometer at eight angles from 23° to 155°. The complex reaction amplitudes associated with the capture channels leading to dipole, quadrupole, and octupole radiation have been extracted. The data at 39 MeV excitation indicate a quadrupole component ${\sigma }_{E2}$/${\sigma }_{E1}$=0.124±0.015, and an octupole component ${\sigma }_{E3}$/${\sigma }_{E1}$=0.0051±0.0026. The observation of high multipolarity radiation is discussed within the context of microscopic calculations which locate large components of the isovector quadrupole and octupole resonances within this region of excitation in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$.

The distribution of magnetic dipole transition strength in ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$ has been measured at excitations between 7.3 and 9.3 MeV using highly polarized tagged photons. A total M1 strength of Σ eV corresponding to B(M1↑)=8.$8_{-0.9}^{+1.1\mathrm{}}$${\mu }_0^2$ was found to be more or less uniformly distributed throughout the region. This result and previous polarized photon measurements in ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ and the Pb nuclei present a consistent picture of M1 strengths in closed-shell nuclei in terms of the required normalization for the spin nucleon g factors. Normalizations with respect to the bare nucleon values are 0.68±0.02 and 0.64±0.03 for the proton and neutron spin g factors, respectively.

The photon spectrum from radiative muon capture in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ has been measured using a time projection chamber as a large acceptance pair spectrometer. The integrated partial branching ratio for photons of $E_{\gamma }$>57 MeV, relative to the ordinary muon capture rate, is (2.2±0.2)×${10}^{\mathrm{-}5}$. When compared to a calculation using a phenomenological nuclear response function the data indicate a value for the induced pseudoscalar coupling in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ of $g_p$/$g_a$=7.3±0.9; however, when compared to a microscopic nuclear-model calculation the value $g_p$/$g_a$${=13.6\mathrm{}}_{\mathrm{-}1.9}^{+1.6\mathrm{}}$ is obtained.

Energy- and angle-resolved nuclear reactions, primarily one-nucleon stripping, have been observed for targets of ${\mathrm{CD}}_2$, Be, and C, using a radioactive ${}_{}{}^8{}_{}{}^{}\mathrm{Li}$ beam ($T_{1/2}$=842 ms) at E=14.3 MeV. The ${(}^8$Li${,}^7$Li) neutron transfer reaction populating discrete final states was identified and angular distributions were obtained. This direct-reaction channel has large cross sections (10–100 mb/sr) due, in part, to the unique nuclear properties of ${}_{}{}^8{}_{}{}^{}\mathrm{Li}$. Implications for astrophysical abundances of Li isotopes may be significant.

A state at 14.283 MeV excitation has been observed in high-resolution inelastic proton scattering on ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$. The state has been identified as the isovector $6^{\mathrm{-}}$ stretched state on the basis of comparison with (d,d’) and (e,e’) data. The normalization factor to make calculation fit the observed strength is 0.047, which is smaller than that observed in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$.