We introduce a higher partial wave generalization of the newly derived integral representations for the s-wave off-shell Jost function and use it to present a number of case studies. An important virtue of the present approach is its simplicity.

A fast method is presented for nonlocal optical model calculations, utilizing the Lanczos method for solving an integral equation derived from the Schrödinger equation. The method is tested against ‘‘exact’’ solutions for a few examples, demonstrating its usefulness. It is further pointed out that the method is well adapted for solving large dimension coupled-channels equations very efficiently.

Several recent papers purport to ‘‘test’’ the Gamow-Teller sum rule. They compare the differences between incomplete strength function integrals for the ${\mathrm{\beta }}^{\mathrm{-}}$ and ${\mathrm{\beta }}^{+}$ directions with the quantity 3(N-Z) and interpret discrepancies as degrees of failure of the sum rule. We point out that the Gamow-Teller sum rule is an exact operator relationship, not a model to be tested. It is useful for determining whether a measured strength function is complete.

We reply to the preceding Comment.

The contribution of spin density term towards the real part of heavy-ion interaction potential estimated by Kaur and Chattopadhyay [Phys. Rev. C 36, 1016 (1987)] is shown to be incorrect.

The thermal neutron cross section for the reaction n${+}^3$He${\to }^4$He+γ is calculated with the Monte Carlo method from realistic variational wave functions obtained for the Argonne ${\mathit{v}}_{14}$ two-nucleon and Urbana VII three-nucleon interaction models. The calculated cross section is found to be almost entirely due to exchange currents. With the exchange current operator constructed so as to satisfy the continuity equation with the Argonne ${\mathit{v}}_{14}$ interaction, the calculated cross section is 71 μb, which is close to the empirical value 54±6 μb. The less certainly known contributions from model-dependent exchange current mechanisms increase the predicted value to about 112 μb. The calculated cross section depends strongly on the n${+}^3$He scattering length, varying between 140 and 71 μb as the scattering length is changed from 3.25 to 3.75 fm.

The total cross section for the γd→${\mathrm{\pi }}^{\mathrm{-}}$pp reaction has been measured for incident photon energies from 380 to 840 MeV in steps of 10 MeV, with the best energy resolution attained so far. A large-acceptance detector was used to observe the reaction products. Overall uncertainties in the deduced cross sections are less than 9% (∼4% statistical and ∼8% systematic). The results are in excellent agreement with previous bubble chamber measurements and do not show any statistically significant structure which can be interpreted as evidence for the formation of dibaryon resonances. An upper limit at 95% confidence level of ${\mathrm{\sigma }}_{\mathrm{peak}}$Γ<230 μb MeV is obtained for a resonance in the vicinity of photon energy 700 MeV (mass∼2490 MeV).

We derive expressions for the low energy behavior of the multipole amplitudes of ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(γ,n${)}^1$H. Our results follow from the relativistic treatment of the long wavelength limit for the photon. We enforce unitarity, point out the incompatibility of this with gauge invariance, and suggest a possible solution. We discuss in some detail the forward differential cross section.

Wave-function components containing a single Δ isobar are included in the calculation of the three-nucleon bound state. In extension to previous work, a nucleon-Δ potential based on meson exchange is incorporated in the interaction models. The interaction models are constructed phase equivalent with the purely nucleonic Paris and Bonn one boson exchange potential in q space (OBEPQ) potentials. The nucleon-Δ potential yields an additional contribution of the order of 0.1–0.2 MeV to the effective three-nucleon force. Its effect on the electromagnetic properties of the three-nucleon bound state is also considered and found to be small.

We explain the empirical linear relations between the triplet scattering length, or the asymptotic normalization constant, and the deuteron matter radius using the effective range expansion in a manner similar to a recent paper by Bhaduri et al. We emphasize the corrections due to the finite force range and to shape dependence. The discrepancy between the experimental values and the empirical line shows the need for a larger value of the wound extension, a parameter which we introduce here. Short-distance nonlocality of the n-p interaction is a plausible explanation for the discrepancy.

Gamma spectroscopy, coincidence, and angular correlation experiments were performed in an extensive study of ${}_{}{}^{132}{}_{}{}^{}\mathrm{Cs}$ decay. The population intensities of states in ${}_{}{}^{132}{}_{}{}^{}\mathrm{Xe}$ and ${}_{}{}^{132}{}_{}{}^{}\mathrm{Ba}$ were measured and some upper limits determined. The logft value of the transition to the $4_1^{+}$ state of ${}_{}{}^{132}{}_{}{}^{}\mathrm{Ba}$ differs significantly from previously published values. A new gamma transition of 688 keV was detected and located in the level scheme of ${}_{}{}^{132}{}_{}{}^{}\mathrm{Xe}$. Angular correlation measurements were performed with a Ge(Li)-NaI(Tl) spectrometer. Kumar-Baranger-type calculations were performed for the ${}_{}{}^{132}{}_{}{}^{}\mathrm{Xe}$ and the results are compared to those of other collective models.

Rotational bands in the odd-odd nucleus ${}_{}{}^{182}{}_{}{}^{}\mathrm{Ir}$ and in the odd-mass isotopes ${}_{}{}^{181,183}{}_{}{}^{}\mathrm{Ir}$ have been studied via the fusion-evaporation reactions ${}_{}{}^{172,174}{}_{}{}^{}\mathrm{Yb}$${(}^{14}$N,xn) utilizing γ-ray spectroscopy techniques. The different band structures in ${}_{}{}^{182}{}_{}{}^{}\mathrm{Ir}$ are interpreted as specific couplings of proton and neutron single-quasiparticles present in neighboring odd Ir and Os and Pt nuclei.

Several rotational bands have been populated to high spin in ${}_{}{}^{127}{}_{}{}^{}\mathrm{Cs}$ following the ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$${(}^{11}$B,4n) reaction. Rotational bands built on low-lying proton ${\mathit{g}}_{7/2}$, ${\mathit{d}}_{5/2}$, and ${\mathit{g}}_{9/2}$ (hole) orbitals, and the unique-parity ${\mathit{h}}_{11/2}$ orbital were observed and identified. For the π${\mathit{g}}_{9/2}$ (hole) case, both signatures were seen in a strongly coupled ΔI=1 band, while for the other cases, decoupled ΔI=2 bands were observed with strong in-band quadrupole transitions. Through comparisons with cranked-shell-model calculations, these band structures are understood to be associated with a prolate (γ∼0°) deformed nuclear shape. At frequencies above ħω=0.3 MeV, the rotational alignment of a pair of ${\mathit{h}}_{11/2}$ neutrons was observed for each of the ${\mathit{h}}_{11/2}$, ${\mathit{g}}_{7/2}$, and ${\mathit{d}}_{5/2}$ bands. This neutron alignment is predicted to drive the nuclear core away from a prolate shape towards the collectively rotating oblate (γ=-60°) shape. Changes in the measured signature splittings for the bands below and above the alignment are consistent with the shape changes.

Gamma-ray and conversion electron singles and coincidence spectroscopy have been performed on the decay of 6.2-h ${}_{}{}^{127}{}_{}{}^{}\mathrm{Cs}$ to levels of ${}_{}{}^{127}{}_{}{}^{}\mathrm{Xe}$ and 30-h ${}_{}{}^{129}{}_{}{}^{}\mathrm{Cs}$ to levels of ${}_{}{}^{129}{}_{}{}^{}\mathrm{Xe}$. From these data, new levels, transition multipolarities, and spin and parity assignments are derived. The systematic structure of the odd-mass Xe nuclides with 69≤N<81 is shown and the results of various calculations are discussed. Support for the use of relatively weak coupling models to describe these nuclides is enumerated.