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Nuclear Theory·nucl-th

Monday·June 6, 2022

11 papers—5 primary·6 cross-listed

All11Primary5Cross-lists6
  1. 06

    [Submitted on 2 Jun 2022] (cross-list from hep-th)

    Chiral anomaly induces superconducting baryon crystal

    Geraint W. Evans🇬🇧 · Andreas Schmitt🇬🇧

    It was previously shown within chiral perturbation theory that the ground state of QCD in a sufficiently large magnetic field and at nonvanishing, but not too large, baryon chemical potential is a so-called chiral soliton lattice. The crucial ingredient of this observation was the chiral anomaly in the form of a Wess-Zumino-Witten term, which couples the baryon chemical potential to the magnetic field and the gradient of the neutral pion field. It was also shown that the chiral soliton lattice becomes unstable towards charged pion condensation at larger magnetic fields. We point out that this instability bears a striking resemblance to the second critical magnetic field of a type-II superconductor, however with the superconducting phase appearing upon increasing the magnetic field. The resulting phase has a periodically varying charged pion condensate that coexists with a neutral pion supercurrent. We construct this phase analytically in the chiral limit and show that it is energetically preferred. Just like an ordinary type-II superconductor, it exhibits a hexagonal array of magnetic flux tubes, and, due to the chiral anomaly, a spatially oscillating baryon number of the same crystalline structure.

    Comments:
    30 pages, 2 figures; v2: references added, minor improvements in the text, typo in Eq. (3.20) corrected, version accepted for publication in JHEP
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2206.01227 [pdf]
    JHEP(2022)·39 citations
  2. 07

    [Submitted on 2 Jun 2022] (cross-list from astro-ph.IM)

    An Improved Method for Coupling Hydrodynamics with Astrophysical Reaction Networks

    M. Zingale · M. P. Katz · A. Nonaka · M. Rasmussen

    Reacting astrophysical flows can be challenging to model because of the difficulty in accurately coupling hydrodynamics and reactions. This can be particularly acute during explosive burning or at high temperatures where nuclear statistical equilibrium is established. We develop a new approach based on the ideas of spectral deferred corrections (SDC) coupling of explicit hydrodynamics and stiff reaction sources as an alternative to operator splitting that is simpler than the more comprehensive SDC approach we demonstrated previously. We apply the new method to a double detonation problem with a moderately-sized astrophysical nuclear reaction network and explore the timestep size and reaction network tolerances to show that the simplified-SDC approach provides improved coupling with decreased computational expense compared to traditional Strang operator splitting. This is all done in the framework of the Castro hydrodynamics code, and all algorithm implementations are freely available.

    Comments:
    accepted to ApJ. Castro is available at https://github.com/amrex-astro/Castro -- all code for the results here is in the github repo
    Subjects:
    Instrumentation and Methods for Astrophysics (astro-ph.IM); Nuclear Theory (nucl-th)
    arXiv:
    2206.01285 [pdf]
    ApJ(2022)·7 citations
  3. 08

    [Submitted on 2 Jun 2022] (cross-list from hep-ph)

    Information field based global Bayesian inference of the jet transport coefficient

    Man Xie🇨🇳 · Weiyao Ke🇺🇸 · Hanzhong Zhang🇨🇳 · Xin-Nian Wang🇺🇸

    Bayesian statistical inference is a powerful tool for model-data comparisons and extractions of physical parameters that are often unknown functions of system variables. Existing Bayesian analyses often rely on explicit parametrizations of the unknown function. It can introduce long-range correlations that impose fictitious constraints on physical parameters in regions of the variable space that are not probed by the experimental data. We develop an information field (IF) approach to modeling the prior distribution of the unknown function that is free of long-range correlations. We apply the IF approach to the first global Bayesian inference of the jet transport coefficient as a function of temperature () from all existing experimental data on single-inclusive hadron, di-hadron and -hadron spectra in heavy-ion collisions at RHIC and LHC energies. The extracted exhibits a strong -dependence as a result of the progressive constraining power when data from more central collisions and at higher colliding energies are incrementally included. The IF method guarantees that the extracted -dependence is not biased by a specific functional form.

    Comments:
    7 pages in RevTex with 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2206.01340 [pdf]
    PRC(2023)·66 citations
  4. 09

    [Submitted on 3 Jun 2022] (cross-list from hep-ph)

    Towards a theory of hadron resonances

    Maxim Mai🇩🇪 · Ulf-G. Meißner🇩🇪 · Carsten Urbach🇩🇪

    In this review, we present the current state of the art of our understanding of the spectrum of excited strongly interacting particles and discuss methods that allow for a systematic and model-independent calculation of the hadron spectrum. These are lattice QCD and effective field theories. Synergies between both approaches can be exploited allowing for deeper understanding of the hadron spectrum. Results based on effective field theories and hadron-hadron scattering in lattice QCD or combinations thereof are presented and discussed. We also show that the often used Breit-Wigner parameterization is at odds with chiral symmetry and should not be used in case of strongly coupled channels.

    Comments:
    75 pages, 21 figures, commissioned article for Physics Reports
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2206.01477 [pdf]
    Phys.Rept.(2023)·156 citations
  5. 10

    [Submitted on 3 Jun 2022] (cross-list from hep-ph)

    Electron Mass Singularities in Semileptonic Kaon Decays

    Chien-Yeah Seng🇩🇪 · William J. Marciano🇺🇸 · Ulf-G. Meißner🇩🇪

    We show that recent improvements in the long-distance quantum electrodynamics (QED) corrections to the radiative inclusive decay rate using the Sirlin representation are free from infrared divergences and collinear electron mass singularities in the limit , as predicted by the Kinoshita-Lee-Nauenberg theorem. We also verify that in massless QED with the simultaneous dimensional regularization of QED photon infrared divergences and electron mass singularities leads to the same result for the inclusive rate in the limit of four space-time dimensions. The equivalence of the two approaches results in part from an interesting interplay between a small chirality-breaking effect in the massless electron limit and the generalization of space-time algebra and phase space integrals to dimensions. Our finding supports the small theoretical uncertainty claimed for radiative inclusive rates and reaffirms its utility in precision unitarity tests of the quark mixing matrix.

    Comments:
    Version accepted by Physical Review D
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2206.01513 [pdf]
    PRD(2022)·3 citations
  6. 11

    [Submitted on 3 Jun 2022] (cross-list from hep-ph)

    Axion effects in the stability of hybrid stars

    Bruno S. Lopes🇧🇷 · Ricardo L. S. Farias🇧🇷 · Veronica Dexheimer🇺🇸 · Aritra Bandyopadhyay🇨🇳 · Rudnei O. Ramos🇧🇷

    We investigate the effects of including strong charge-parity (CP) violating effects through axion fields in the microscopic equation of state of massive hybrid neutron stars. We assume that their cores contain deconfined quark matter and include the effects of axions via an effective 't Hooft determinant interaction. The hadronic crusts are described using different approaches in order to make our results more general. We find that the presence of axions stabilizes massive hybrid neutron stars against gravitational collapse by weakening the deconfinement phase transition and bringing it to lower densities. This enables to reproduce hybrid neutron stars in agreement with modern astrophysical constraints.

    Comments:
    6 pages, 2 figures, replaced with updated version matching the published one
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2206.01631 [pdf]
    PRD(2022)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE