PaperPanorama

Nuclear Theory·nucl-th

Thursday·June 27, 2019

12 papers7 primary·5 cross-listed

  1. 08

    Bounce Configuration from Gradient Flow

    So Chigusa🇯🇵 · Takeo Moroi🇯🇵 · Yutaro Shoji🇯🇵

    Based on the gradient flow, we propose a new method to determine the bounce configuration for false vacuum decay. Our method is applicable to a large class of models with multiple fields. Since the bounce is a saddle point of an action, a naive gradient flow method which minimizes the action does not work. We point out that a simple modification of the flow equation can make the bounce its stable fixed point while the false vacuum configuration an unstable one. Consequently, the bounce configuration can be obtained simply by following the flow without a careful choice of an initial configuration. With numerical analysis, we confirm the validity of our claim, checking that the flow equation we propose indeed has solutions that flow into the bounce configuration.

    hep-phastro-ph.COhep-thnucl-thPLB(2020)·29 citations
  2. 09

    A note on scalar meson dominance

    Y. Ünal🇩🇪 · Ulf-G. Meißner🇩🇪

    We consider chiral perturbation theory with an explicit broad -meson and study its contribution to the scalar form factors of the pion and the nucleon. Our goal is to learn more about resonance saturation in the scalar sector.

    hep-phnucl-thCPC(2019)·0 citations
  3. 10

    Neutron spin structure from polarized deuteron DIS with proton tagging

    W. Cosyn🇧🇪 · C. Weiss🇺🇸

    Polarized electron-deuteron deep-inelastic scattering (DIS) with detection of the spectator proton ("tagged DIS") enables measurements of neutron spin structure with maximal control of nuclear effects. We calculate the longitudinal spin asymmetries in polarized tagged DIS using methods of light-front nuclear structure and study their dependence on the measured proton momentum. Asymmetries can be formed with all three deuteron spin states () or the two maximum-spin states only (, involving tensor polarization). The proton momentum dependence can be used to select pure S-wave configurations in the deuteron and eliminate D-wave depolarization (transverse momenta 100 MeV). Free neutron spin structure can be extracted model-independently through pole extrapolation of the tagged asymmetries. Such measurements could be performed at a future electron-ion collider (EIC) with polarized deuteron beams and forward proton detectors.

    hep-phnucl-exnucl-thPLB(2019)·10 citations
  4. 11

    Radial oscillations of quark stars from perturbative QCD

    José C. Jiménez🇧🇷 · Eduardo S. Fraga🇧🇷

    We perform the general relativistic stability analysis against radial oscillations of unpaired quark stars obtained using the equation of state for cold quark matter from perturbative QCD, the only free parameter being the renormalization scale. This approach consistently incorporates the effects of interactions and includes a built-in estimate of the inherent systematic uncertainties in the evaluation of the equation of state. We also take into account the constraints imposed by the recent gravitational wave event GW 170817 to the compact star masses and radii, and restrict their vibrational spectrum.

    hep-phastro-ph.HEgr-qcnucl-thPRD(2019)·23 citations
  5. 12

    Gluon Field Digitization for Quantum Computers

    Andrei Alexandru🇺🇸 · Paulo F. Bedaque🇺🇸 · Siddhartha Harmalkar🇺🇸 · Henry Lamm🇺🇸 · Scott Lawrence🇺🇸 · Neill C. Warrington (for the NuQS Collaboration)🇺🇸

    Simulations of gauge theories on quantum computers require the digitization of continuous field variables. Digitization schemes that uses the minimum amount of qubits are desirable. We present a practical scheme for digitizing gauge theories via its discrete subgroup . The standard Wilson action cannot be used since a phase transition occurs as the coupling is decreased, well before the scaling regime. We proposed a modified action that allows simulations in the scaling window and carry out classical Monte Carlo calculations down to lattice spacings of order fm. We compute a set of observables with sub-percent precision at multiple lattice spacings and show that the continuum extrapolated value agrees with the full results. This suggests that this digitization scheme provides sufficient precision for NISQ-era QCD simulations.

    hep-latnucl-thphysics.comp-phquant-phPRD(2019)·163 citations

Affiliations

first authorsco-authorsvia INSPIRE