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Nuclear Theory·nucl-th

Friday·July 1, 2022

16 papers—10 primary·6 cross-listed

All16Primary10Cross-lists6
  1. 11

    [Submitted on 29 Jun 2022] (cross-list from hep-ph)

    The f0(1370) controversy from dispersive meson-meson scattering data analyses

    Jose Ramon Pelaez🇪🇸 · Arkaitz Rodas🇺🇸 · Jacobo Ruiz de Elvira🇪🇸

    We establish the existence of the long-debated resonance in the dispersive analyses of meson-meson scattering data. For this, we present a novel approach using forward dispersion relations, valid for generic inelastic resonances. We find its pole at MeV in scattering. We also provide the couplings as well as further checks extrapolating partial-wave dispersion relations or with other continuation methods. A pole at MeV also appears in the data analysis with partial-wave dispersion relations. Despite settling its existence, our model-independent dispersive and analytic methods still show a lingering tension between pole parameters from the and channels that should be attributed to data.

    Comments:
    13 pages, 8 figures. v2 version: improved results for the f0(1370) pole determination in the pipi to KKbar channel, minor amendments, appendices expanded
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2206.14822 [pdf]
    PRL(2023)·30 citations
  2. 12

    [Submitted on 29 Jun 2022] (cross-list from quant-ph)

    Bound State Internal Interactions as a Mechanism for Exponential Decay

    Peter W. Bryant🇺🇸

    We hypothesize that the binding interactions among the components of bound systems and the background fields, sometimes known as virtual particle exchange, affect the state of the systems as do typical scattering interactions. Then with the assumption that the interior environment of unstable particles is disordered, we derive in the limit of continuous binding both an exactly exponential non-decay probability and Fermi's Golden Rule for the decay rates. The result suggests resolutions to several long-standing theoretical challenges associated with exponential decay in quantum mechanics, without appealing directly to non-Hermitian, approximate Hamiltonians or complex energies. It also contributes to a conceptual understanding of the continuum between controlled interactions that induce deviations from exponential decay, such as those in the Quantum Zeno Effect, and the uncontrolled internal dynamics of excited atoms and nuclei, which exhibit no such deviations. Finally, we examine how the binding interactions responsible for the general exponential character of decay for bound systems differ from the couplings with decay products that control decay rates, providing insight into challenges in quantum computing and information processing.

    Comments:
    12 pages, 0 figures. This article supersedes arXiv:1309.5347
    Subjects:
    Quantum Physics (quant-ph); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    2206.14875 [pdf]
    Found.Phys.(2025)·0 citations
  3. 13

    [Submitted on 30 Jun 2022] (cross-list from hep-ph)

    Effective spectral function of vector mesons via lifetime analysis

    Renan Hirayama🇩🇪 · Jan Staudenmaier🇩🇪 · Hannah Elfner🇩🇪

    Effective spectral functions of the meson are reconstructed by considering the lifetimes inside different media using the hadronic transport SMASH (Simulating Many Accelerated Strongly-interacting Hadrons). Due to inelastic scatterings, resonance lifetimes are dynamically shortened (collisional broadening), even though the employed approach assumes vacuum resonance properties. Analyzing the meson lifetimes allows to quantify an effective broadening of the decay width and spectral function, which is important in order to distinguish dynamical effects from additional genuine medium modifications to the spectral functions, indicating e.g. an onset of chiral symmetry restoration. The broadening of the spectral function in a thermalized system is shown to be consistent with other theoretical calculations. The effective meson spectral function is also presented for the dynamical evolution of heavy-ion collisions, finding a clear correlation of the broadening to system size, which is explained by an observed dependence of the width on the local hadron density. Furthermore, the difference in the results between the thermal system and full collision dynamics is explored, which may point to non-equilibrium effects.

    Comments:
    9 pages, 12 figures. Ancillary files divided by system
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2206.15166 [pdf]
    PRC(2023)·13 citations
  4. 14

    [Submitted on 30 Jun 2022] (cross-list from hep-ph)

    Flow correlations from a hydrodynamics model with dynamical freeze-out and initial conditions based on perturbative QCD and saturation

    H. Hirvonen🇫🇮 · K.J. Eskola🇫🇮 · H. Niemi🇫🇮

    We extend the applicability of the hydrodynamics, perturbative QCD and saturation -based EKRT (Eskola-Kajantie-Ruuskanen-Tuominen) framework for ultrarelativistic heavy-ion collisions to peripheral collisions by introducing dynamical freeze-out conditions. As a new ingredient compared to the previous EKRT computations we also introduce a non-zero bulk viscosity. We compute various hadronic observables and flow correlations, including normalized symmetric cumulants, mixed harmonic cumulants and flow-transverse momentum correlations, and compare them against measurements from the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). We demonstrate that the inclusion of the dynamical freeze-out and bulk viscosity allows a better description of the measured flow coefficients in peripheral collisions and enables the use of an extended centrality range when constraining the properties of QCD matter in the future.

    Comments:
    22 pages, 17 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2206.15207 [pdf]
    PRC(2022)·18 citations
  5. 15

    [Submitted on 30 Jun 2022] (cross-list from astro-ph.HE)

    Onset of Electron Captures and Shallow Heating in Magnetars

    Nicolas Chamel🇧🇪 · Anthea Francesca Fantina🇧🇪

    The loss of magnetic pressure accompanying the decay of the magnetic field in a magnetar may trigger exothermic electron captures by nuclei in the shallow layers of the stellar crust. Very accurate analytical formulas are obtained for the threshold density and pressure, as well as for the maximum amount of heat that can be possibly released, taking into account the Landau-Rabi quantization of electron motion. These formulas are valid for arbitrary magnetic field strengths, from the weakly quantizing regime to the most extreme situation in which electrons are all confined to the lowest level. Numerical results are also presented based on experimental nuclear data supplemented with predictions from the Brussels-Montreal model HFB-24. This same nuclear model has been already employed to calculate the equation of state in all regions of magnetars.

    Comments:
    23 pages, 14 figures. Full numerical results available on Zenodo at https://doi.org/10.5281/zenodo.6604639
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2206.15222 [pdf]
    Universe(2022)·4 citations
  6. 16

    [Submitted on 30 Jun 2022] (cross-list from hep-ph)

    Temperature dependence of the static quark diffusion coefficient

    Debasish Banerjee🇮🇳 · Rajiv Gavai🇮🇳 · Saumen Datta🇮🇳 · Pushan Majumdar🇮🇳

    The energy loss pattern of a low momentum heavy quark in a deconfined quark-gluon plasma can be understood in terms of a Langevin description. In thermal equilibrium, the motion can then be parametrized in terms of a single heavy quark momentum diffusion coefficient kappa, which needs to be determined nonperturbatively. In this work, we study the temperature dependence of kappa for a static quark in a gluonic plasma, with a particular emphasis on the temperature range of interest for heavy ion collision experiments.

    Comments:
    12 pages, 9 figures. The discussion section and the appendix substantially modified, two figures added, typos fixed
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2206.15471 [pdf]
    NPA(2023)·39 citations

Affiliations

first authorsco-authorsvia INSPIRE