We have measured the zero degree cross sections for the ${}_{}{}^{14}{}_{}{}^{}(\mathit{p}$,n) reaction leading to the (2.31+3.95) MeV states in ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ at energies of 200, 300, and 450 MeV. Cross sections for the Fermi transition to the 2.31 MeV state and for the Gamow-Teller transition to the 3.95 MeV state have been extracted using earlier measurements of the cross-section ratios. The results are compared with calculations using G-matrix effective interactions based on the Paris potential, and on one of the Bonn potentials, and a t-matrix effective interaction derived from nucleon-nucleon phase shifts. The best fit to both the present results and earlier results at lower energies is provided by calculations based on the Bonn potential.

States in doubly odd ${}_{}{}^{218}{}_{}{}^{}\mathrm{Ac}$ have been studied using in-beam α-, γ-, and $e^{\mathrm{-}}$-spectroscopy techniques mainly through the ${}_{}{}^{209}{}_{}{}^{}\mathrm{C}$,3n) fusion-evaporation reaction. ${}_{}{}^{218}{}_{}{}^{}\mathrm{Ac}$ shows a band structure, with interleaved states of alternating parities connected by enhanced B(E1) transitions, which is strikingly similar to the one in its isotone ${}_{}{}^{217}{}_{}{}^{}\mathrm{Ra}$.

Mass and charge distributions have been measured for damped projectile-like fragments in the reaction ${}_{}{}^{74}{}_{}{}^{}$Ge${+}^{165}$Ho at 8.5 MeV per nucleon bombarding energy. Coincidences were measured between angle-correlated reaction partners in order to derive the primary mass distribution and the excitation energy distribution for projectile-like fragments. The evolution of the primary N and Z distributions as a function of energy loss is found to deviate significantly from predictions of the nucleon exchange transport model. The fraction of excitation energy residing in the projectile-like fragment is shown to depend both upon energy loss and the direction of the nucleon flow.

The elastic phase shifts for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{Si}$ scattering obtained by the algebraic approach to scattering theory are used in an inversion procedure at fixed energy. The resulting local optical potential shows oscillations and a dependence on energy. These effects point to an underlying nonlocal interaction.

The high spin states of the ${}_{}{}^{155\mathrm{-}165}{}_{}{}^{}\mathrm{Er}$ isotopes were studied in the interacting boson-fermion model 1. It was found that the energy spectra up to I${=(41/2\mathrm{}}^{+}$ of the even-odd Er isotopes could be reproduced quite well. The observed doublet state structure and the order reverses of the doublet states of the energy spectra of ${}_{}{}^{161}{}_{}{}^{}\mathrm{Er}$ could be reproduced. The unfavored high spin states that currently do not have experimental counterparts are also calculated.

The recent precise measurements of the neutral pion photoproduction on the proton near threshold seems to be inconsistent with the predictions of the low-energy theorems on photoproduction of pions. In this note, we have sought to resolve this problem, in the framework of an approximate SU(2)×SU(2) symmetry of the pion-nucleon dynamics, by incorporating the contribution from the nucleon matrix elements of the equal-time commutator between the divergence of the axial-vector current and the electromagnetic current, which was introduced earlier by Furlan et al. We find that a mean value of the nonstrange quark mass m^=1/2($m_u$+$m_d$)=(7±2) MeV, leads to an estimate of the symmetry breaking terms compatible with experiment.

The inelastic scattering of 134 MeV protons to $6^{\mathrm{-}}$ states in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ has been studied. Five $6^{\mathrm{-}}$ states were identified on the basis of their measured angular distributions and analyzing powers. By combining the results with those of companion electron scattering and (p,n) studies in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ and proton studies in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, it has been possible to extract isoscalar and isovector excitation amplitudes for each state.

A G-parity transformation is performed on the latest version of the Bonn N-N meson-exchange potential to derive the elastic part of the N-N¯ interaction. No additional modification of the intermediate- and short-range domain is introduced. A phenomenological complex potential of Gaussian form is added to account for N-N¯ annihilation. A good description of low- and intermediate-energy N-N¯ data is achieved. The relevance of isobar degrees of freedom in the elastic N-N¯ interaction is discussed.

Differential cross sections for neutrons elastically scattered from ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ and inelastically scattered to the first three excited states ${}_{}{}^{13}{}_{}{}^{}$${\mathrm{C}}^{\mathrm{*}}$(3.09, 3.68, and 3.85 MeV) were measured at 69 incident energies for 4.5≤$E_n$≤11 MeV. A multiple scattering code provided a simulation of the experimental scattering process allowing accurate corrections to the small measured inelastic cross sections. The integrated ${}_{}{}^{13}{}_{}{}^{}$C(n,α${)}^{10}$Be cross section was determined by subtracting the sum of the measured integrated cross sections from the total. Shell-model calculations were used to generate the R-matrix parameters for the elastic and first three inelastic channels of ${}_{}{}^{13}{}_{}{}^{}$C+n, and, after some minor adjustments, the predicted structure generally agreed with experiment for $E_n$<4 MeV. Previous elastic ${}_{}{}^{13}{}_{}{}^{}$C+n data were refitted to replace constant $R_0$ R-matrix background terms by more realistic broad states and to achieve better agreement with model calculations and the data. R-matrix fitting of the full data set produced new ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ level information. For $E_n$>4 MeV ($E_x$>12 MeV), five states were given definite $J^{\pi }$ assignments and three states tentative assignments.

We point out instabilities in some recent probability-nonconserving parametrizations of the nucleon-nucleon elastic-scattering S and K matrices. We find that Arndt and Roper’s K-matrix parameters are stable when the scattering matrix S is near 0 but are unstable when S is near -1 and, for coupled waves, when it is near ${\lim }_{\mathrm{\epsilon }\to 0}$(${\mathrm{S}}_{11}$=${\mathrm{S}}_{22}$=1-ε, $S_{12}$=$S_{21}$=iεexp2iθ), 0°≤θ≤180°. Conversely, we find that the S-matrix parameters of Bryan, of Sprung, and of Klarsfeld are unstable near S=0 but are stable near S=-1 and near the above-mentioned coupled-wave point.

The cross section of the ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$(n,α${)}^{24}$Na reaction relative to that of the ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$(n,f) has been measured by the activation technique in the 7.13–9.01 MeV energy region. The neutron energy resolution varied between 70 and 130 keV (FWHM). The characteristics of the neutron source such as the mean energy of the neutrons and the energy distribution of the neutron flux have been determined experimentally and were validated with theoretical model calculations. The applied experimental techniques made it possible to decrease the overall uncertainty of the measurements to 2–3 %. The results confirm that the excitation function in the investigated energy region has a resonance structure as observed by Schmitt and Halperin in 1961. By using the data obtained for the energy distribution of the neutrons the ‘‘true’’ excitation function has been restored and the parameters of the Lorentz-type peaks have been calculated.

A two-state model that assumed dominant mixing between a ‘‘normal’’ basis ground state and an ‘‘intruder’’ basis excited state was used earlier to describe the wave functions for the physical ground state and an excited $0^{+}$’ state in the germanium isotopes. The wave-function amplitudes deduced for the ground state and $0^{+}$’ state were shown to be consistent with the $0^{+}$’/g.s. cross-section ratios, σ${(0\mathrm{}}^{+}$’)/σ(g.s.), in the ${}_{}{}^{\mathrm{A}}{}_{}{}^{}\mathrm{Ge}$(t,p) and ${}_{}{}^{\mathrm{A}+2\mathrm{}}{}_{}{}^{}\mathrm{Ge}$(p,t) reactions. In this report we investigate whether these same ground-state wave-function amplitudes together with distorted-wave Born-approximation calculations can account for the A dependence in the absolute ${}_{}{}^{\mathrm{A}}{}_{}{}^{}\mathrm{Ge}$(t,p${)}^{A+2\mathrm{}}$Ge(g.s.) cross sections.

Elastic scattering of protons and neutrons from ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ in the energy range up to 61.4 MeV is analyzed in order to establish a consistent phenomenology with which to examine the recent results of dispersion theory. The present analysis avoids conventional assumptions about the energy dependences of potential depths or geometrical parameters and attempts to include estimates of the uncertainty in our knowledge of the derived potential parameters. Recently reported evidence for energy-dependent geometrical parameters in the n${+}^{208}$Pb potential is supported by the present analysis, but no comparable effect is observed for phenomenological proton potentials in the range of available data ($E_p$>9 MeV). The present analysis shows that, unlike the situation for heavy-ion scattering, the Coulomb potential does not cut off the imaginary potential for p${+}^{208}$Pb. Consequently, no rapid excursions in the parameters of the p${+}^{208}$Pb potential are expected to occur until the incident energy is well below the Coulomb barrier where the nuclear potential is essentially unobservable.

The atomic mass excess of ${}_{}{}^{193}{}_{}{}^{}\mathrm{Au}$ was determined to be -33.419±0.011 MeV for the first time from the measured Q value of -26.919±0.009 MeV for the ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$(α${,}^8$He${)}^{193}$Au reaction. The atomic mass excess of ${}_{}{}^{193}{}_{}{}^{}\mathrm{Hg}$ was also determined to be -31.080±0.032 MeV by using the known Q value of ${}_{}{}^{193}{}_{}{}^{}\mathrm{Hg}$ beta decay to ${}_{}{}^{193}{}_{}{}^{}\mathrm{Au}$. These results were compared with some predicted values.

Elastic photon scattering at the excitation energy of the giant dipole resonance in medium- and heavy-mass nuclei is described by a coherent superposition of Thomson, Delbrück, and nuclear Rayleigh amplitudes, the last being evaluated within the framework of the interacting boson model. New accurate tables of Delbrück amplitudes are also given for 9≤$E_{\gamma }$≤30 MeV and 0°<θ<120°. .AE

Inclusive γ rays at 90° and 125° and particle spectra (for Z=1 to 6) at 14° and (Z=1 to 4) at 120° and 150° were measured. Particle-γ-ray coincidences were obtained. Cross sections for heavy residuals were extracted from in-beam γ-ray and radioactivity measurements. Target-projectile-like correlations were well reproduced using a geometrical abrasion model plus preequilibrium and equilibrium decay.

A statistical decay model has been used to calculate inclusive and coincidence cross sections for the formation of projectile fragments from the collision of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ (2.1 GeV/nucleon) with a carbon target. The model predicts fragment momenta parallel and perpendicular to the projectile direction. Good agreement with experimental results is obtained for the inclusive yields of fragments and for the momenta, and fairly good agreement for coincidence yields.

A relativistic Vlasov-Uehling-Uhlenbeck equation for the nuclear phase-space distribution function is derived from the Walecka model through the use of semiclassical, local, and Born approximations.

The elastic scattering vector analyzing powers for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{16}$O at 25.7 MeV and ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{12}$C at 30 MeV have been measured. In addition, measurement of the vector analyzing power for inelastic ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ scattering has been made for the $2^{+}$ (4.44 MeV) state in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$. Excitation function data for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$${+}^{16}$O elastic and inelastic scattering have also been measured at five angles for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ lab energies through the range 15–28 MeV in 375 keV steps. These data show the system to be resonance free at 25.7 MeV. The data have been analyzed in the coupled channels framework, employing the double folding model for the real part of the nuclear scattering potential. The coupling strengths in the coupled channels calculations were determined from inelastic scattering cross-section data directly. The elastic scattering vector analyzing powers arise from a complicated interference between channel coupling and spin-orbit contributions, whereas the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, $2^{+}$ inelastic vector analyzing power arises from the spin-orbit potential only. Inelastic scattering analyzing powers may allow the shape and strength of heavy-ion spin-orbit potentials to be investigated more clearly than do the elastic scattering analyzing powers. The normalization of the double-folded real potential was found to be in the range 0.85–1.00 in the coupled channel calculations, thus bringing the normalization of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ scattering into agreement with other projectiles.