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Nuclear Theory·nucl-th

Monday·December 21, 2015

7 papers—5 primary·2 cross-listed

All7Primary5Cross-lists2
  1. 01

    [Submitted on 17 Dec 2015]

    van der Waals and Casimir-Polder interactions between neutrons

    James F. Babb · Mahir S. Hussein

    We investigate the van der Waals interaction between neutrons using the theory of Casimir and Polder, wherein the potential for asymptotically large separations falls off as the inverse seventh power, and compare it to the similar interaction between a neutron and a proton, for which the asymptotic interaction falls off as the inverse fourth power. Modifications of the formalism to extend the validity to smaller separations using dynamic electric and magnetic dipole polarizability data are discussed

    Comments:
    2 pages. To appear in the proceedings of the 21st International Conference on Few-Body Problems in Physics (FB21), May 2015, Chicago, USA
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1512.05792 [pdf]
    EPJ Web Conf.(2016)·1 citation
  2. 02

    [Submitted on 18 Dec 2015]

    Hollow nuclear matter

    Gao-Chan Yong

    It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. And the size of inner bubble in these matter is affected by the charge number of nuclear matter. Existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.

    Comments:
    5 pages, 6 figures, PRC, in production
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
    arXiv:
    1512.05829 [pdf]
    PRC(2016)·10 citations
  3. 03

    [Submitted on 18 Dec 2015]

    Correlations between neutrons and protons near Fermi surface and of super-heavy nuclei

    Ning Wang🇨🇳 · Min Liu🇨🇳 · Xizhen Wu🇨🇳 · Jie Meng🇨🇳

    The shell corrections and shell gaps in nuclei are systematically studied with the latest Weizsäcker-Skyrme (WS4) mass model. We find that most of asymmetric nuclei with (sub)-shell closures locate along the shell stability line (SSL), , which might be due to a strong correlation between neutrons and protons near Fermi surface. The double magicity of nuclei Si and Ni is predicted according to the corresponding shell gaps, shell corrections and nuclear deformations. The unmeasured super-heavy nuclei 118 and 120, with relatively large shell gaps and shell corrections, also locate along the SSL, whereas the traditional magic nucleus Fl evidently deviates from the line. The -decay energies of super-heavy nuclei with are simultaneously investigated by using the WS4 model together with the radial basis function corrections. For super-heavy nuclei with large shell corrections, the smallest -decay energy for elements , 117 and 118 in their isotope chains locates at rather than .

    Comments:
    to appear in Phys. Rev. C
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1512.05845 [pdf]
    PRC(2016)·22 citations
  4. 04

    [Submitted on 18 Dec 2015]

    Constrained-Path Quantum Monte-Carlo Approach for Non-Yrast States Within the Shell Model

    J. Bonnard🇮🇹 · O. Juillet🇫🇷

    The present paper intends to present an extension of the constrained-path quantum Monte-Carlo approach allowing to reconstruct non-yrast states in order to reach the complete spectroscopy of nuclei within the interacting shell model. As in the yrast case studied in a previous work, the formalism involves a variational symmetry-restored wave function assuming two central roles. First, it guides the underlying Brownian motion to improve the efficiency of the sampling. Second, it constrains the stochastic paths according to the phaseless approximation to control sign or phase problems that usually plague fermionic QMC simulations. Proof-of-principle results in the valence space are reported. They prove the ability of the scheme to offer remarkably accurate binding energies for both even- and odd-mass nuclei irrespective of the considered interaction.

    Comments:
    11 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1512.06011 [pdf]
    EPJA(2016)·0 citations
  5. 05

    [Submitted on 18 Dec 2015]

    Three-body systems in physics of cold atoms and halo nuclei

    Chen Ji

    Few-body systems, such as cold atoms and halo nuclei, share universal features at low energies, which are insensitive to the underlying inter-particle interactions at short ranges. These low-energy properties can be investigated in the framework of effective field theory with two-body and three-body contact interactions. I review the effective-field-theory studies of universal physics in three-body systems, focusing on the application in cold atoms and halo nuclei.

    Comments:
    Review article commissioned for the International Journal of Modern Physics E special issue on "Effective Field Theory in Nuclear Physics"; 26 pages
    Subjects:
    Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); Atomic Physics (physics.atom-ph)
    arXiv:
    1512.06114 [pdf]
    IJMPE(2016)·8 citations
  6. 06

    [Submitted on 18 Dec 2015] (cross-list from hep-lat)

    The pole structure of the Lambda(1405) in a recent QCD simulation

    R. Molina🇺🇸 · M. Doring🇺🇸

    The baryon is difficult to detect in experiment, absent in many quark model calculations, and supposedly manifested through a two-pole structure. Its uncommon properties made it subject to numerous experimental and theoretical studies in recent years. Lattice-QCD eigenvalues for different quark masses were recently reported by the Adelaide group. We compare these eigenvalues to predictions of a model based on Unitary Chiral Perturbation Theory. The UCHPT calculation predicts the quark mass dependence remarkably well. It also explains the overlap pattern with different meson-baryon components, mainly and , at different quark masses. More accurate lattice QCD data are required to draw definite conclusions on the nature of the .

    Comments:
    14 pages, 4 figures
    Subjects:
    High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1512.05831 [pdf]
    PRD(2016)·63 citations
  7. 07

    [Submitted on 18 Dec 2015] (cross-list from cond-mat.str-el)

    Polynomial Similarity Transformation Theory: A smooth interpolation between coupled cluster doubles and projected BCS applied to the reduced BCS Hamiltonian

    Matthias Degroote · Thomas M. Henderson · Jinmo Zhao · Jorge Dukelsky · Gustavo E. Scuseria

    We present a similarity transformation theory based on a polynomial form of a particle-hole pair excitation operator. In the weakly correlated limit, this polynomial becomes an exponential, leading to coupled cluster doubles. In the opposite strongly correlated limit, the polynomial becomes an extended Bessel expansion and yields the projected BCS wavefunction. In between, we interpolate using a single parameter. The effective Hamiltonian is non-hermitian and this Polynomial Similarity Transformation Theory follows the philosophy of traditional coupled cluster, left projecting the transformed Hamiltonian onto subspaces of the Hilbert space in which the wave function variance is forced to be zero. Similarly, the interpolation parameter is obtained through minimizing the next residual in the projective hierarchy. We rationalize and demonstrate how and why coupled cluster doubles is ill suited to the strongly correlated limit whereas the Bessel expansion remains well behaved. The model provides accurate wave functions with energy errors that in its best variant are smaller than 1\% across all interaction stengths. The numerical cost is polynomial in system size and the theory can be straightforwardly applied to any realistic Hamiltonian.

    Subjects:
    Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
    arXiv:
    1512.06111 [pdf]
    PRB(2016)·31 citations

Affiliations

first authorsco-authorsvia INSPIRE