Equations for O+ states in deformed nuclei

The quasiparticle-phonon nuclear model equations are derived for describing theKπ=O⁺ states in doubly even deformed nuclei taking account of particle-hole and particle-particle interactions between quasiparticles. Inclusion of particle-particle interactions complicates the RPA equations. Equations for the functions of monopole and quadrupole pairing are derived from the condition of eliminating spurious RPA solutions. In the QPNM, inclusion of a particle-particle interaction does not lead to very complicated calculations. The obtained equations can serve as a basis for calculating characteristics of the O⁺ excited states of doubly even deformed nuclei.     

The decay of the18O giant dipole resonance to excited residual nuclear states

The decay of the¹⁸O GDR to excited residual nuclear states has been examined by measuring spectra of prompt deexcitationγ-rays. The target was irradiated by bremsstrahlung with endpoint energies of 23.5 and 28 MeV. “Bremsstrahlung-weighted” integrated cross sections are given for the population of the residual nuclear states in¹⁷O,¹⁷N,¹⁶O and¹⁴C. Proton decay to excited states in¹⁷N is remarkably weak. It seems that 1p _3/2 excitations play only a minor role in the¹⁸O GDR.     

From regular to chaotic states in atomic nuclei

This work has been partially supported by the Ministero dell’Università e della Ricerca Scientifica e Tecnologica (MURST) and by the INFN-CICYT Agreement.     

Neutron inelastic scattering to octupole states in single-closed-shell nuclei

Differential cross sections for the excitation of the first octupole-vibrational state in the closed- neutron-shell nuclides ⁸⁸Sr and ⁹⁰Zr and in the closed-proton shell-nuclei ^{116, 118, 120, 124}Sn by 11 MeV neutrons are presented. The distorted-wave Born approximation is used to obtain deformation lengths, σ(3^?), for each state. Results are compared with earlier measurements of inelastic proton scattering to the same states. Although limited resolution in the neutron time- of-flight spectrometer complicates the interpretation of the Sn data, the overall conclusion that σ_nn′(3^?) ≈ σ_pp′(3^?) is supported by all of the measurements.     

On the rotational states in light nuclei

Some properties of the projected Hartree-Fock functions which describe the ground state bands in ⁸Be, ¹²C and ²⁰Ne, and the excited 8p-8h band in ¹⁶O are studied in order to answer the question whether these states correspond to real rotational motion in these light nuclei.     

Systematization of cross sections for the production of residual nuclei on separated tin isotopes in reactions induced by various-energy protons

Cross sections for the production of residual nuclei on the isotopes ^{112,118,120,124}Sn irradiated with 0.66-, 1.0-, 3.65-, and 8.1-GeV proton beams were investigated. A ten-parameter semiempirical formula was used to systematize the cross sections in question. A comparative analysis of parameter values obtained at different proton energies was performed.     

Strangeness production on the nucleon and on nuclei

The coupled-channel Giessen Model is used to investigate meson production on the nucleon simultaneously in reactions with hadrons and the photon. The essential aspects of the model are discussed. Results for strangeness producing KΛ reactions on the proton and eta photoproduction on the proton and the neutron, respectively, are presented. A resonance model is used to explore the production of hypernuclei in proton and photon induced reactions.     

Hadron final states in deep-inelastic leptoproduction on nuclei

We discuss some aspects of the formation of inclusive hadron final states in deep-inelastic electro-, muo- and neutrinoproduction on nuclear targets.The inclusive final states are known to possess a remarkable Q² independence in interactions with free nucleons. Nevertheless, we prove that the nuclear spectra and mean multiplicities should have a rather specific and appreciable dependence on Q². In leptoproduction on heavy nuclei the yields of particles in nucleus fragmentation rise by a factor of two, as at the fixed energy transfer v one passes from incoherent scattering to diffraction scattering, and the total multiplicities change by 20–40%. The effects predicted seem to be detectable with the current and the near-future experimental facilities. Fermilab bubble chamber neutrino experiments and the coming SPS muon and neutrino experiments deserve special attention in this respect. We also comment on the possibilities offered by leptoproduction on nuclei for testing some absorption models.     

Comparison of residual nuclei from relativistic ion and antiproton reactions with nuclei

The distribution of residual nuclei after stopped antiproton annihilation in several targets from Cu to Ho has been compared with a recent empirical parametrization of mass and charge yields which is supposed to be valid for relativistic light and heavy ion induced reactions. The basic structure of the proposed formula is also applicable for antiproton induced fragmentation or spallation, but some specific modifications are suggested.     

Systematics of low-lying octupole states in the doubly-even nuclei from Ge to Sr

Low-lying octupole states of doubly-even ^78–86Kr isotopes have been studied with inelastic scattering of 51.9 MeV protons. It is shown that in the doubly-even nuclei from Ge to Sr with N = 42–50, the lowest octupole vibrational energies of nuclei with equal neutron excess are almost the same. The transition strengths of these states increase with Z.     

Theory of the excited states of deformable even-even nuclei

The excited states of nonspherical even-even nuclei are discussed taking the change in nuclear shape during excitation into account.     

On the energy spectra of single-particle states in nuclei

The single-particle spectra of ¹⁶O, ⁴⁰Ca, ⁴⁸Ca and ⁵⁶Ni have been studied using self- consistent field methods and a quadratically velocity-dependent two-nucleon effective (reaction- matrix) interaction. The self-consistent field equations are derived in some detail for the spin- independent interaction which is used. A one-body spin-orbit interaction of the Thomas form is added.     

Excited states of deformable nonaxial odd nuclei

Rotationally single-particle and vibrational excitations of deformable nonaxial odd nuclei are investigated with allowance for the interaction of collective and single-particle states. The ratios of excitation energies, of reduced probabilities of E2 transitions, and of quadrupole moments for deformed nonaxial odd nuclei are calculated up to high-spin states.