Showing papers in "Nuclear Physics in 1968"

TL;DR: In this article, the shell correction method was used to calculate the effect of nucleon shells in deformed and spherical nuclei, and the results were presented in such a way as to illustrate more clearly the effects of shell shells on nucleon nuclei.

TL;DR: In this paper, the orthogonality and completeness properties of the resonant states as defined by Humblet and Rosenfeld are investigated using a simple regularization method first suggested by Zel'dovich.

TL;DR: In this article, the shell-model reaction matrix elements for the 0f-1p shell are calculated and tabulated and compared with available empirical effective interactions and used to calculate (i) the spectra of the valence particles of 42Ca, 42Sc, 50Ca, 50Sc and 50Ti, (ii) the changes of single-particle (hole) levels such as the changes from 41Ca to 49Ca and (iii) the 0 f 7 2 −0 d 3 2 particleparticle states of 38Cl and the corresponding particle-hole states of

TL;DR: In this paper, the potential energy of deformation with pairing-plus-quadrupole model for nuclei with N = 82-126, Z = 50-82, and Z = 74-80 was calculated.

TL;DR: In this paper, the energy levels for A = 4 nuclei with emphasis on material leading to information about the structure of the A =4 systems were analyzed. But the authors focused on the A -4 nuclei.

TL;DR: In this article, the quasipotential type equation for the relativistic scattering amplitude is obtained with the help of a special kind of perturbation theory, which is called perturbative perturbations.

TL;DR: In this paper, the experimental nucleon-nucleon phase shifts are used to deduce matrix elements of the nucleon nucleon potential in a basis of harmonic oscillator wave functions of the interparticle distance.

TL;DR: The low-lying even-parity energy levels and wave functions of the even isotopes of tungsten, osmium and platinum are calculated within the framework of Bohr's collective Hamiltonian as mentioned in this paper.

TL;DR: In this article, the pairing-plus-quadrupole matrix elements are compared with those of more realistic interactions, and it is decided to keep only matrix elements between states of two adjacent oscillator shells.

TL;DR: In this article, a separable interaction model is used to represent the low-energy two-nucleon central and tensor forces, and an attempt is made to establish which of these two experimental values is consistent with the experimental binding energy.

TL;DR: Theoretical calculations of the potential energy surface as a function of quadrupole and hexadecapole distortion parameters are reported for super-heavy nuclei with Z near 114 and N near 184 as mentioned in this paper.

TL;DR: In this article, an effective nucleon-nucleon interaction of Wigner type V ( r ) = V N exp(− r 2 / γ 2 ) is assumed to induce the scattering.

TL;DR: In this article, the generator-coordinate method of Griffin, Hill and Wheeler was applied to the alpha-particle model of 20Ne and the results of the solution were shown to be equivalent to the quantal equations of a set of coupled harmonic oscillators.

TL;DR: In this article, the static and non-static Bryan-Scott potentials were adapted to the nucleon-antinucleon system, and they were obtained in the 0-300 MeV range.

TL;DR: Explicit algebraic expressions for SU(3) ⊃ R (3) Wigner coefficients are given in this article, which are of particular interest in p-shell and 2s-1d shell model calculations.

TL;DR: A theory of collective motion based on the time-dependent Hartree-Bogolyubov approximation for the pairing-plus-quadrupole model was proposed in this article.

TL;DR: In this article, the Bell-Treiman transformation was used to investigate the perturbation theory of massive Yang-Mills fields with the help of Bell-treiman transformation and showed that primitive diagrams containing one closed loop are convergent if there are more than four external vector boson lines.

TL;DR: In this paper, ifJ π = 0 − states of the eight nuclei 16 O, 40 Ca, 48 Ca, 56 Ni, 90 Zr, 114 Sn, 140 Ce and 208 Pb are computed in the framework of the particle-hole model with the Tamm-Dancoff and random phase approximations.

TL;DR: In this paper, a theory of coherent and incoherent production of particles in medium and heavy nuclei at very high energies where threshold effects are negligible is presented, and the modification necessary for coherent production at lower energies (of the order of a few GeV or less) is made.

TL;DR: In this article, a real optical model potential of Woods-Saxon form is obtained which closely reproduces the observed scattering of neutrons and protons from 4 He at bombarding energies below 20 MeV.

TL;DR: Partial photoneutron cross sections have been measured up to 30 MeV using quasi-monochromatic photons resulting from annihilation-in-flight in this article, where the direct effect of neutrons contribution varies between 17 and 30%.

TL;DR: In this paper, the authors reviewed the motivation and basic assumptions of the pairing-plus-quadrupole model and made analytical and numerical applications to the single-j shell, demonstrating the competition between the deforming effect of the quadrupole force and the spherifying effect of pairing force.

TL;DR: In this paper, a superconvergent combination of weak baryon form factors is constructed from the assumptions that the usually adopted transformation properties of the baryons and the vector and axial vector currents are exact for matrix elements in the limit of infinite t, and that the direct vector and the axial-vector form factors are convergent.

TL;DR: In this paper, the effective gyromagnetic ratios of the ground-state rotational band in deformed nuclei have been calculated on the basis of the cranking model formula, and the latter has been evaluated in terms of deformed shell-model wave functions with inclusion of pair correlations.

TL;DR: In this article, a generalization of the standard inner product integral is developed, which allows one to treat resonant states on an equal footing with bound states, and the resonant and bound states are shown to form an orthonormal set with respect to the generalized inner product.

TL;DR: Core polarization renormalizes the single-particle strength by ≈ 25% in intermediate and heavy nuclei and produces a corresponding increase in the effective mass of particles near the Fermi surface as discussed by the authors.

TL;DR: In this paper, the activation method was used to measure (n, 2n) excitation-functions in the energy region 12.6-19.6 MeV for 52Cr, 75As, 85Rb, 106Cd, 112Sn, 121Sb, 140Ce, 142Ce and 141Pr, 144Sm, 165Ho and 181Ta.

TL;DR: In this paper, the divergence of the corresponding current emphasizes low frequencies and a corresponding general method to calculate the σ terms is outlined, which turns out to be proportional to a rather small overall factor ≈ μ π / M N, but several mechanisms are pointed out by which they can nevertheless become important.

TL;DR: The subthreshold fission cross section of 240 Pu has been measured in the energy range between 200 eV and 8 keV as mentioned in this paper, and the fission spectrum obtained shows a periodical appearance of groups of resonances with particularly high fission widths.

TL;DR: In this article, the internal conversion spectra of deformed nuclei in the mass interval 173 ≦ A ≦ 185 were investigated with permanent magnet spectrographs and partial decay schemes were deduced from energy sums, multipolarities and intensities of the transitions.