PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·August 6, 2020

7 papers—6 primary·1 cross-listed

All7Primary6Cross-lists1
  1. 01

    [Submitted on 4 Aug 2020]

    Zero-pairing and zero-temperature limits of finite temperature Hartree-Fock-Bogoliubov theory

    Thomas Duguet🇫🇷 · Wouter Ryssens🇺🇸

    Recently, the zero-pairing limit of Hartree-Fock-Bogoliubov (HFB) mean-field theory was studied in detail in arXiv:2006.02871. It was shown that such a limit is always well-defined for any particle number A, but the resulting many-body description differs qualitatively depending on whether the system is of closed-(sub)shell or open-(sub)shell nature. Here, we extend the discussion to the more general framework of Finite-Temperature HFB (FTHFB) which deals with statistical density operators, instead of pure many-body states. We scrutinize in detail the zero-temperature and zero-pairing limits of such a description, and in particular the combination of both limits. For closed-shell systems, we find that the FTHFB formulism reduces to the (zero-temperature) Hartree-Fock formulism, i.e. we recover the textbook solution. For open-shell systems, however, the resulting description depends on the order in which both limits are taken: if the zero-temperature limit is performed first, the FTHFB density operator demotes to a pure state which is a linear combination of a finite number of Slater determinants, i.e. the case of arXiv:2006.02871. If the zero-pairing limit is performed first, the FTHFB density operator remains a mixture of a finite number of Slater determinants with non-zero entropy, even as the temperature vanishes. These analytical findings are illustrated numerically for a series of Oxygen isotopes.

    Comments:
    16 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th); Superconductivity (cond-mat.supr-con); physics.chem-ph (physics.chem-ph)
    arXiv:
    2008.01859 [pdf]
    PRC(2020)·8 citations
  2. 02

    [Submitted on 4 Aug 2020]

    Effective interactions between nuclear clusters

    Yoshiko Kanada-En'yo · Dean Lee

    The effective interactions between two nuclear clusters, , , and , are investigated within a cluster model using local nucleon-nucleon~() forces. It is shown that the interaction in the spin-aligned system is repulsive for all inter-cluster distances, whereas the and spin-aligned systems are attractive at intermediate distances. The Pauli blocking between identical-nucleon pairs is responsible for the cluster-cluster repulsion and becomes dominant in the shallow binding limit. We demonstrate that two -clusters could be bound if the force has nonzero range and is strong enough to form a deeply bound -cluster, or if the force has both even-parity and odd-parity attraction. Effective dimer-dimer interactions for general quantum systems of two-component fermions are also discussed in heavy-light mass limit, where one component is much heavier than the other, and their relation to inter-cluster interactions in nuclear systems are discussed. Our findings provide a conceptual foundation for conclusions obtained numerically in the literature, that increasing the range or strength of the local part of the attractive nucleon-nucleon interaction results in a more attractive cluster-cluster interaction.

    Comments:
    16 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); Atomic Physics (physics.atom-ph)
    arXiv:
    2008.01867 [pdf]
    PRC(2021)·12 citations
  3. 03

    [Submitted on 5 Aug 2020]

    Signature of intermittency in hybrid UrQMD-hydro data at 10 AGeV Au+Au collisions

    Somen Gope🇮🇳 · Buddhdeb Bhattacharjee🇮🇳

    An attempt has been made, in the light of scaled factorial moment (SFM) analysis, to investigate hybrid UrQMD hydro generated events of Au+Au collisions at 10 AGev to realize the role of hydrodynamic evolution on observed intermittency, if any. ln <F_q> values for q = 2 - 6 are found to increase with increasing values of ln M^2 indicating unambiguously the presence of intermittency in our data sample generated with both chiral and hadronic equation of states (EOS). Although various late processes like meson-meson (MM) and meson-baryon (MB) hadronic rescattering and/or resonance decays are to influence the intermittency index significantly, these processes could not be held responsible for the observed intermittency in hybrid UrQMD hydro data.

    Comments:
    11 pages, 12 figure, 1 table
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2008.01943 [pdf]
    EPJA(2021)·12 citations
  4. 04

    [Submitted on 5 Aug 2020]

    Symmetry conserving Coupled Cluster Doubles wave function and the Self-Consistent odd particle number RPA

    Mohsen Jemaï🇹🇳 · Peter Schuck🇫🇷

    Mixing single and triple fermions an exact killing operator of the Coupled Cluster Doubles (CCD) wave function with good symmetry was found in \cite{Tohy13}. Using these operators with the equation of motion (EOM) method the so-called self-consistent odd particle number random phase approximation (odd-RPA) was set up. Together with the stationarity condition of the two body density matrix it is shown that the killing conditions allow to reduce the order of correlation functions contained in the matrix elements of the odd-RPA equations to a fully self consistent equation for the single particle occupation numbers. Excellent results for the latter and the ground state energies are obtained in an exactly solvable model from weak to strong couplings.

    Comments:
    9 pages, 3 figures
    Subjects:
    Nuclear Theory (nucl-th); Strongly Correlated Electrons (cond-mat.str-el)
    arXiv:
    2008.01975 [pdf]
    EPJA(2020)·1 citation
  5. 05

    [Submitted on 5 Aug 2020]

    The F nucleus as a lighthouse on the coast of the island of inversion

    L. Fortunato · J. Casal · W. Horiuchi · Jagjit Singh · A. Vitturi

    The exotic, neutron-rich and weakly-bound isotope F stands out as a waymarker on the southern shore of the island of inversion, a portion of the nuclear chart where the effects of nuclear forces lead to a reshuffling of the single particle levels and to a reorganization of the nuclear structure far from stability. This nucleus has become very popular, as new measurements allow to refine theoretical models. We review the latest developments and suggest how to further assess the structure by proposing predictions on electromagnetic transitions that new experiments of Relativistic Coulomb Excitation should soon become able to measure.

    Comments:
    11 pages, 4 figures; perspective article
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2008.01978 [pdf]
    Commun.Phys.(2020)·24 citations
  6. 06

    [Submitted on 5 Aug 2020]

    Connecting spatial moments and momentum densities

    M. Hoballah🇫🇷 · M.B. Barbaro🇮🇹 · R. Kunne.🇫🇷 · M. Lassaut.🇫🇷 · D. Marchand🇫🇷 · G. Quéméner🇫🇷 · E. Voutier🇫🇷 · J. van de Wiele🇫🇷

    The precision of experimental data and analysis techniques is a key feature of any discovery attempt. A striking example is the proton radius puzzle where the accuracy of the spectroscopy of muonic atoms challenges traditional electron scattering measurements. The present work proposes a novel method for the determination of spatial moments from densities expressed in the momentum space. This method provides a direct access to even, odd, and more generally any real, negative and positive moment with order larger than . As an illustration, the application of this method to the electric form factor of the proton is discussed in detail.

    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2008.02009 [pdf]
    PLB(2020)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE