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Nuclear Theory·nucl-th

Friday·August 3, 2018

10 papers—4 primary·6 cross-listed

All10Primary4Cross-lists6
  1. 01

    Pauli-principle driven correlations in four-neutron nuclear decays

    P. G. Sharov🇷🇺 · L. V. Grigorenko🇷🇺 · A. Ismailova🇷🇺 · M. V. Zhukov🇸🇪

    Mechanism of simultaneous non-sequential four-neutron () emission (or `true' -decay) has been considered in phenomenological five-body approach. This approach is analogous to the model of the direct decay to the continuum often applied to - and -decays. It is demonstrated that -decay fragments should have specific energy and angular correlations reflecting strong spatial correlations of `valence' nucleons orbiting in their -precursors. Due to the Pauli exclusion principle, the valence neutrons are pushed to the symmetry-allowed configurations in the -precursor structure, which causes a `Pauli focusing' effect. Prospects of the observation of the Pauli focusing have been considered for the -precursors H and O. Fingerprints of their nuclear structure or/and decay dynamics are predicted.

    nucl-thJETP Lett.(2019)·6 citations
  2. 02

    Exact restoration of Galilei invariance in density functional calculations with quantum Monte Carlo

    P. Massella🇮🇹 · F. Barranco🇪🇸 · D. Lonardoni🇺🇸 · A. Lovato🇮🇹 · F. Pederiva🇮🇹 · E. Vigezzi🇮🇹

    Galilean invariance is usually violated in self-consistent mean-field calculations that employ effective density-dependent nuclear forces. We present a novel approach, based on variational quantum Monte Carlo techniques, suitable to preserve this symmetry and assess the effect of its violation, seldom attempted in the past. To this aim, we generalize the linear optimization method to encompass the density-dependence of effective Hamiltonians, and study He, O, and Ca ground-state properties employing the Gogny interaction.

    nucl-thJ.Phys.G(2020)·15 citations
  3. 03

    Empirical signatures of shape phase transitions in nuclei with odd nucleon numbers

    D. Bucurescu🇷🇴 · N.V. Zamfir🇷🇴

    Nuclear level density at low excitation energies is proposed as an indicator of the first order phase transitions in nuclei. The new signature, a maximum value of the level density at the critical point, appears to be sensitive to the detailed way the phase transition takes place in different nuclear regions: it is consistent with phase coexistence in the N=90 region, and with a rapid crossing of the two phases, without their coexistence/mixing at the critical point in the N=60 region, respectively. Candidates for critical point nuclei are proposed for odd-mass and odd-odd nuclei, using correlations between relative excitation energies, and their ratios, for structures (bands) based on unique-parity orbitals.

    nucl-thnucl-exPRC(2018)·11 citations
  4. 04

    Direct and indirect transfer in the elastic O+C scattering

    Nguyen Tri Toan Phuc · Nguyen Hoang Phuc · Dao T. Khoa

    The extensive elastic O+C scattering data measured at low energies show consistently an oscillating enhancement of the elastic cross section at backward angles that is difficult to describe within the conventional optical model. Given the significant spectroscopic factors predicted for the dissociation OC by the shell model (SM) and -cluster model calculations, the contribution of the transfer channels to the elastic O+C scattering should not be negligible, and is expected to account for the enhanced oscillation of the elastic cross section at backward angles. To reveal the impact of the transfer, a systematic coupled reaction channels (CRC) analysis of the elastic O+C scattering has been performed where the multistep couplings between the elastic and inelastic scattering channels, the direct and indirect transfer channels were treated explicitly, using the real optical potentials and inelastic scattering form factors determined by the double-folding model. We show that a consistent CRC description of the elastic O+C data at different energies can be obtained over the whole angular region, using the spectroscopic factors determined recently in the large scale SM calculation. The present CRC results are, therefore, of interest not only for the nuclear scattering studies but also provide an important spectroscopic information on the cluster dissociation of O.

    nucl-thnucl-exPRC(2018)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE