A general discussion of nonrelativistic multichannel scattering for nonlocal potentials is presented. The approach is based on the extensive use of the Fredholm determinants that are associated with the integral equations occurring at various points of the theory. Special attention is paid to situations where confining potentials are present, as in nonrelativistic quark models of hadron-hadron interactions. Some standard results of multichannel scattering theory for local potentials and one-channel theory for nonlocal ones are generalized in this context, including Levinson’s theorem.

Inelastic electron scattering cross sections for ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ have been calculated at 180°. The wave functions employed are those generated in the recoil-corrected continuum shell-model framework with the M3Y g-matrix interaction. The calculations include the complete, translationally invariant transition operator and pion-exchange current contributions. Good agreement is obtained with data at ${\mathit{E}}_0$=60.6, 130, and 200 MeV. Approximations to the full operator and their implications for single-particle models of nucleon knockout are discussed.

The generalized Levinson theorem for systems involving nonlocal and confining potentials is illustrated by a nonrelativistic quark model for the NN interaction, formulated within the framework of the resonating group (RG) method. In order to apply the results of the preceding paper to this problem, we first show how the system of integro-differential equations of the RG method can be transformed into a system of coupled Schrödinger equations with nonlocal potentials. The forbidden states arising in the many-channel wave function from the Pauli principle are then shown to play the same role as normalizable bound states, as far as the generalized Levinson theorem is concerned. Numerical results are presented for the l=0 partial wave in the (ST)=(01) channel.

Recent measurements of parity nonconserving (PNC) effects in ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ and ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ contradict the results of random matrix theory for nuclear compound states. In this work the value of the PNC effect is expressed in terms of a wave function at the nuclear surface where the wave function of the compound state is not ‘‘random’’ due to boundary conditions. A mechanism is suggested which can explain the permanent sign and large value of these effects. The correlations between compound-state components are considered. The T- and P-odd effects can be expressed in terms of observed P-odd effects. The ‘‘dynamical enhancement’’ of small interactions in other reactions and other systems is also discussed.

The propagation of a density disturbance in nuclear fluid is considered for the case when the nuclear equation of state is derived from a Skyrme-type effective nucleon-nucleon potential. It is shown that the velocity-dependent terms of this potential are responsible for the possible formation of solitary waves in nuclear matter. These solitons are rarefaction waves and not compressional as previously suggested. Their amplitudes increase with increasing temperature, which makes them a possible mechanism for nuclear multifragmentation.

We have measured the in-plane polarization transfer coefficients for the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$(p,p’) reaction using a longitudinally polarized beam at 65 MeV. A microscopic distorted-wave Born-approximation analysis with the M3Y interaction has been performed for the excitation to the first $0^{+}$ state (T=1). The isovector tensor force ${\mathit{V}}_{\mathit{T}\mathrm{\tau }}$ and the isovector spin-orbit force ${\mathit{V}}_{\mathit{L}\mathit{S}\mathrm{\tau }}$ have been adjusted in order to reproduce the experimental differential cross sections, depolarization parameters, and in-plane polarization transfer coefficients. This analysis suggests that the high-momentum components of ${\mathit{V}}_{\mathit{T}\mathrm{\tau }}$ should be substantially reduced from the M3Y interaction and ${\mathit{V}}_{\mathit{L}\mathit{S}\mathrm{\tau }}$ needs to be more attractive.

Recent measurements of the analyzing power ${\mathit{A}}_{\mathit{y}}$ for elastic proton-proton scattering are compared to predictions of phase-shift analyses and potential models. One measurement is an absolute determination of ${\mathit{A}}_{\mathit{y}}$ at a beam energy of 183.1 MeV. The second measurement is a precise determination of the angular distribution ${\mathit{A}}_{\mathit{y}}$(θ) over the angular range ${\mathrm{\theta }}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=5.45°–21.36° at a beam energy of 185.4 MeV. At these small angles the interference between the Coulomb and nuclear amplitudes dominates ${\mathit{A}}_{\mathit{y}}$(θ). Potential model calculations without the electromagnetic spin-orbit force fail to reproduce the data. Phase-shift analyses, all of which include some form of the electromagnetic spin-orbit force, tend to have a better overall agreement with the data than the potential models.

Comparison of data for neutron-deuteron and proton-deuteron analyzing power ${\mathit{A}}_{\mathit{y}}$ for elastic scattering has become crucial for investigating charge-symmetry breaking in the ${}_{}{}^3{}_{}{}^{}$P nucleon-nucleon interactions. We extended this comparison down to 5 MeV and find that the relative difference between n-d and p-d scattering at the ${\mathit{A}}_{\mathit{y}}$ maximum near 120° increases with decreasing energy. By applying a straightforward Coulomb ‘‘correction’’ to the p-d data, we account for most of the difference, suggesting that the Coulomb force, rather than charge-symmetry breaking, is responsible for most of the observed difference.

A shell-model study is made of second-forbidden unique β decay of ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$, and ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$. Calculations were made with a p-shell interaction for ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$ and the sd-shell interaction of Wildenthal for ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$ and ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$. The resulting second-forbidden unique matrix elements are consistently larger than experiment. The ratio is discussed in terms of two effects: the ‘‘collective suppression’’ discussed in 1970 by Warburton, Garvey, and Towner and in-medium quenching of the spin operator. Comparison is made to similar effects for M3 transitions.

We point out that the large integral cross section values reported for the ${}_{}{}^{180}{}_{}{}^{}\mathrm{Ta}_{}^{\mathit{m}}{}_{}{}^{}$(γ,γ’${)}^{180}$Ta reaction by Collins et al. correspond to transition strengths exceeding the recommended upper limits. The small overall cross section ratio of the aforementioned and the ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}$(γ,γ’${)}^{115}$${\mathrm{In}}^{\mathit{m}}$ reactions is shown to be an indirect piece of evidence against the enormous integral cross sections. Collins et al. used the ${}_{}{}^{87}{}_{}{}^{}\mathrm{Sr}$(γ,γ’${)}^{87}$${\mathrm{Sr}}^{\mathit{m}}$ reaction to verify their calculated photon flux, but did not identify the observed activation levels. We identify four photoactivation levels of ${}_{}{}^{87}{}_{}{}^{}\mathrm{Sr}$ at 1228.42 keV, 5/$2^{+}$, 1770.46 keV, 5/$2^{+}$, 1919.9 keV, 7/$2^{+}$, 2706.5 keV, 9/$2^{+}$, and deduce the existence of (at least) a further one around 2.6 MeV. These new data suggest that the calculated photon flux used by Collins et al. should be rechecked.

We investigate the magnetic and quadrupole moments of deuteron in the Bethe-Salpeter formalism with a special attention on keeping Lorentz covariance, starting directly from the expression in the Breit frame of conserved electromagnetic deuteron current. As a result, from general and qualitative arguments, it is pointed out that the well-known difficulty concerning the static moments in the nonrelativistic nuclear potential models may be solved through a ‘‘normalization effect’’: That is, if we assume an admixture of negative-energy amplitudes with magnitude of a few hundredths of positive ones, we can fit both the experimental values of magnetic and quadrupole moments at the same time with a single value of the D-wave state probability ${\mathit{P}}_{\mathit{D}}$=0.06. Furthermore, through a tentative quantitative analysis, supposing the ordinary one-boson-exchange interactions, it is shown that such a situation may be reasonably expected.

We reply to the preceding Comment.

We point out that the shell-model calculations of Wolters, van Hees, and Glaudemans for the p-shell nuclei in a (0+2)ħω basis has several serious consistency problems, and we use the case of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ to illustrate these problems. We discuss some limitations of the parametrization used for effective interaction, criticize the choice of experimental data used in the least-squares fit, and demonstrate that the resultant interaction exhibits some peculiar features which make it differ considerably from realistic interactions.

In the preceding Comment, our shell-model calculations on p-shell nuclei are heavily criticized. In this Reply we argue that our calculations are relevant.

Population of certain states seen in recent high-resolution photoproton spectra of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ at photon energies between 61 and 77 MeV was taken as evidence for photoabsorption by T=1 proton-neutron pairs. This Comment suggests that the results might be more simply explained by the presence of admixed ground states in these nuclei.

We reply to the preceding Comment.

The different β-delayed particle-decay modes of ${}_{}{}^{31}{}_{}{}^{}\mathrm{Ar}$ are investigated by means of a new silicon-detector telescope. Identification of β-delayed two-proton decay, and β-delayed three-proton decay observed for the first time, is made possible by Monte Carlo simulations of the detector response. Other β-delayed single-proton branches are also investigated, and none of the energetically allowed β-α and β-pα decay modes are found. Finally, the results of this experiment are compared to shell-model calculations.

The present work extends the systematics of nuclear charge radii obtained by the method of muonic atoms to nuclei with 8≤Z,N≤20. The accuracy of the measured muonic Lyman transition energies of generally ≤10 eV leads to a precision in the model-independent nuclear charge radii differences of 2–3 am for the isotope shifts and 4–9 am for isotone shifts. Both isotope and isotone shifts within the s-d shell behave ‘‘anomalously’’ with respect to the systematics of heavier nuclei. However, such behavior is predicted on theoretical grounds, if mixing in the s-d shells and the strong deformation of some of the nuclei in this region are considered. We compare charge radii from elastic electron scattering data with muonic atom rms radii and suggest that observed deviations are possibly due to incomplete dispersion corrections.

High-spin states belonging to ${}_{}{}^{166}{}_{}{}^{}\mathrm{Lu}$ have been studied through the ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tb}$${(}^{12}$C,5n) fusion-evaporation reaction in the energy range E${(}^{12}$C)=75–90 MeV. In-beam and activity singles spectra and γ-γ-t coincidences have been measured. A completely new level scheme is proposed. Each rotational band is interpreted on the basis of coupling scheme systematics. g-S crossing frequencies and alignments have been extracted. B(M1)/B(E2) reduced transition probability ratios have been calculated using a semiclassical method and compared to the experimental values.

The analyzing power ${\mathit{A}}_{\mathit{y}}$(θ) for pp elastic scattering at 185.4 MeV has been measured with a new technique in which the polarized beam in a storage ring was scattered from an internal ${\mathrm{H}}_2$ gas target. The measurement covered the angular range ${\mathrm{\theta }}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=5.45°–21.36°, where ${\mathit{A}}_{\mathit{y}}$ is dominated by interference between Coulomb and nuclear amplitudes. It is found that electromagnetic spin-orbit effects are required to explain the data. The present measurement demonstrates for the first time the feasibility and the advantages of nuclear physics experiments with polarized beams in storage rings.