PaperPanorama

Nuclear Theory·nucl-th

Wednesday·June 8, 2016

7 papers5 primary·2 cross-listed

  1. 01

    [Submitted on 7 Jun 2016]

    Avoiding common pitfalls and misconceptions in extractions of the proton radius

    Jan C. Bernauer🇺🇸 · Michael O. Distler🇩🇪

    In a series of recent publications, different authors produce a wide range of electron radii when reanalyzing electron proton scattering data. In the light of the proton radius puzzle, this is a most unfortunate situation. However, we find flaws in most analyses that result in radii around 0.84 fm. In this paper, we explain our reasoning and try to illustrate the most common pitfalls.

    Comments:
    Preliminary version as discussion basis for the ECT* workshop on 'The proton radius puzzle', Trento 2016
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    1606.02159 [pdf]
    16 citations
  2. 02

    [Submitted on 7 Jun 2016]

    Three pion nucleon coupling constants

    E. Ruiz Arriola🇪🇸 · J. E. Amaro🇪🇸 · R. Navarro Perez🇺🇸

    There exist four pion nucleon coupling constants, , , and which coincide when up and down quark masses are identical and the electron charge is zero. While there is no reason why the pion-nucleon-nucleon coupling constants should be identical in the real world, one expects that the small differences might be pinned down from a sufficiently large number of independent and mutually consistent data. Our discussion provides a rationale for our recent determination based on a partial wave analysis of the self-consistent nucleon-nucleon Granada-2013 database comprising 6713 published data in the period 1950-2013.

    Comments:
    15 pages, 6 figures. Invited talk at the Workshop on Determination of the Fundamental Parameters in QCD, Mainz Institute of Theoretical Physics, Johannes Gutenberg University of Mainz. Corrected Version matching publication in Mod. Phys. Lett. A
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    1606.02171 [pdf]
    Mod.Phys.Lett.A(2016)·12 citations
  3. 03

    [Submitted on 7 Jun 2016]

    Nambu-Goldstone modes in the random phase approximation

    Kai Neergård

    I show that the kernel of the random phase approximation (RPA) matrix based on a stable Hartree, Hartree-Fock, Hartree-Bogolyubov or Hartree-Fock-Bogolyubov mean field solution is decomposed into a subspace with a basis whose vectors are associated, in the equivalent formalism of a classical Hamiltonian homogeneous of second degree in canonical coordinates, with conjugate momenta of cyclic coordinates (Nambu-Goldstone modes) and a subspace with a basis whose vectors are associated with pairs of a coordinate and its conjugate momentum neither of which enters the Hamiltonian at all. In a subspace complementary to the one spanned by all these coordinates including the conjugate coordinates of the Nambu-Goldstone momenta, the RPA matrix behaves as in the case of a zerodimensional kernel. This result was derived very recently by Nakada as a corollary to a general analysis of RPA matrices based on both stable and unstable mean field solutions. The present proof does not rest on Nakada's general results.

    Comments:
    A point was clarified
    Subjects:
    Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
    arXiv:
    1606.02216 [pdf]
    PTEP(2016)·1 citation
  4. 04

    [Submitted on 7 Jun 2016]

    Nuclear Reactions and Superfluid Time Dependent Density Functional Theory

    Piotr Magierski🇵🇱

    The extension of Time Dependent Density Functional Theory (TDDFT) to superfluid systems is discussed in the context of nuclear reactions and large amplitude collective motion.

    Comments:
    15 pages, to be published in the ebook "Progress of time-dependent nuclear reaction theory" (Betham Science Publishers 2019) honoring Prof. Joachim Maruhn's retirement
    Subjects:
    Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); Superconductivity (cond-mat.supr-con)
    arXiv:
    1606.02225 [pdf]
    APS Physics(2019)·13 citations
  5. 05

    [Submitted on 7 Jun 2016]

    Three-body scattering problem in the fixed center approximation: the case of attraction

    Alexander E. Kudryavtsev🇷🇺 · Vakhid A. Gani🇷🇺 · Alexander I. Romanov🇷🇺

    We study the scattering of a light particle on a bound pair of heavy particles (e.g., the deuteron) within the fixed center approximation in the case of light-heavy attraction, solving the integral equation for the three-body Green's function both in the coordinate and in the momentum space. The results for the three-body scattering amplitude appear to be ambiguous -- they depend on a single real parameter. This parameter may be fixed by a three-body input, e.g., the three-body scattering length. We also solve the integral equation for the three-body Green function in the momentum space, introducing a finite cut-off. We show that all three approaches are equivalent. We also discuss how our approach to the problem matches with the introduction of three-body contact interaction as done by other authors.

    Comments:
    7 pages, 3 figures; v3: figures slightly changed, minor changes to match version published in EPJ A
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1606.02259 [pdf]
    EPJA(2016)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE