PaperPanorama
FAQ

Nuclear Theory·nucl-th

Friday·January 19, 2018

11 papers—7 primary·4 cross-listed

All11Primary7Cross-lists4
  1. 08

    [Submitted on 15 May 2017] (cross-list from nucl-ex)

    Observation of Narrow and Resonances in Reactions

    V. Kuznetsov · F. Mammoliti · F. Tortorici · V. Bellini · V. Brio · A. Gridnev · N. Kozlenko · G. Russo · A.Spatafora · M.L.Sperduto · V.Sumachev · C.Sutera

    Observation of a narrow structure at GeV in the excitation functions of some photon- and pion-induced reactions may signal a new narrow isospin-1/2 resonance. New data on the reactions from GRAAL seems to reveal the signals of both and resonances.

    Comments:
    Published version
    Subjects:
    Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1705.05177 [pdf]
    JETP Lett.(2017)·14 citations
  2. 09

    [Submitted on 18 Jan 2018] (cross-list from hep-ph)

    The radiative corrections to double-Dalitz decays revisited

    Karol Kampf🇨🇿 · Jiri Novotny🇨🇿 · Pablo Sanchez-Puertas🇨🇿

    In this study, we revisit and complete the full next-to-leading order corrections to pseudoscalar double-Dalitz decays within the soft-photon approximation. Comparing to the previous study, we find small differences, which are nevertheless relevant for extracting information about the pseudoscalar transition form factors. Concerning the latter, these processes could offer the opportunity to test them-for the first time-in their double-virtual regime

    Comments:
    22 pages, 9 figures; minor changes added (results unchanged). Matches the published version in PRD. Results in Mathematica notebooks added as ancillary files
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    1801.06067 [pdf]
    PRD(2018)·28 citations
  3. 10

    [Submitted on 18 Jan 2018] (cross-list from cond-mat.quant-gas)

    Pairing correlations across the superfluid phase transition in the unitary Fermi gas

    S. Jensen🇺🇸 · C. N. Gilbreth🇺🇸 · Y. Alhassid🇺🇸

    In the two-component Fermi gas with a contact interaction, a pseudogap regime can exist at temperatures between the superfluid critical temperature and a temperature . This regime is characterized by pairing correlations without superfluidity. However, in the unitary limit of infinite scattering length, the existence of this regime is still debated. To help address this, we have applied finite-temperature auxiliary-field quantum Monte Carlo (AFMC) to study the thermodynamics of the superfluid phase transition and signatures of the pseudogap in the spin-balanced homogeneous unitary Fermi gas. We present results at finite filling factor for the condensate fraction, an energy-staggering pairing gap, the spin susceptibility, and the heat capacity, and compare them to experimental data when available. In contrast to previous AFMC simulations, our model space consists of the complete first Brillouin zone of the lattice, and our calculations are performed in the canonical ensemble of fixed particle number. The canonical ensemble AFMC framework enables the calculation of a model-independent gap, providing direct information on pairing correlations without the need for numerical analytic continuation. We use finite-size scaling to estimate at the corresponding filling factor. We find that the energy-staggering pairing gap vanishes above , showing no pseudogap effects, and that the spin susceptibility shows a substantially reduced signature of a spin gap compared to previously reported AFMC simulations.

    Comments:
    5 pages, 2 figures, and 6 pages, 9 figures of supplemental material
    Subjects:
    Quantum Gases (cond-mat.quant-gas); Superconductivity (cond-mat.supr-con); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1801.06163 [pdf]
    PRL(2020)·32 citations
  4. 11

    [Submitted on 14 Jan 2018] (cross-list from quant-ph)

    On the vacuum-polarization Uehling potential for a Fermi charge distribution

    Jean-Christophe Pain🇫🇷

    We present analytical formulas for the vacuum-polarization Uehling potential in the case where the finite size of the nucleus is modeled by a Fermi charge distribution. Using a Sommerfeld-type development, the potential is expressed in terms of multiple derivatives of a particular integral. The latter and its derivatives can be evaluated exactly in terms of Bickley-Naylor functions, which connection to the Uehling potential was already pointed out in the pure Coulomb case, and of usual Bessel functions of the second kind. The cusp and asymptotic expressions for the Uehling potential with a Fermi charge distribution are also provided. Analytical results for the higher-order-contribution Källèn-Sabry potential are given.

    Comments:
    submitted to European Physical Journal D
    Subjects:
    Quantum Physics (quant-ph); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    1801.06173 [pdf]
    Eur.Phys.J.D(2018)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE