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Nuclear Theory·nucl-th

Tuesday·May 18, 2021

15 papers—10 primary·5 cross-listed

All15Primary10Cross-lists5
  1. 11

    [Submitted on 14 May 2021] (cross-list from astro-ph.HE)

    Constraints on the dense matter equation of state and neutron star properties from NICER's mass-radius estimate of PSR J0740+6620 and multimessenger observations

    G. Raaijmakers · S. K. Greif · K. Hebeler · T. Hinderer · S. Nissanke · A. Schwenk · T. E. Riley · A. L. Watts · J. M. Lattimer · W. C. G. Ho

    In recent years our understanding of the dense matter equation of state (EOS) of neutron stars has significantly improved by analyzing multimessenger data from radio/X-ray pulsars, gravitational wave events, and from nuclear physics constraints. Here we study the additional impact on the EOS from the jointly estimated mass and radius of PSR J0740+6620, presented in Riley et al. (2021) by analyzing a combined dataset from X-ray telescopes NICER and XMM-Newton. We employ two different high-density EOS parameterizations: a piecewise-polytropic (PP) model and a model based on the speed of sound in a neutron star (CS). At nuclear densities these are connected to microscopic calculations of neutron matter based on chiral effective field theory interactions. In addition to the new NICER data for this heavy neutron star, we separately study constraints from the radio timing mass measurement of PSR J0740+6620, the gravitational wave events of binary neutron stars GW190425 and GW170817, and for the latter the associated kilonova AT2017gfo. By combining all these, and the NICER mass-radius estimate of PSR J0030+0451 we find the radius of a 1.4 solar mass neutron star to be constrained to the 95% credible ranges 12.33^{+0.76}_{-0.81} km (PP model) and 12.18^{+0.56}_{-0.79} km (CS model). In addition, we explore different chiral effective field theory calculations and show that the new NICER results provide tight constraints for the pressure of neutron star matter at around twice saturation density, which shows the power of these observations to constrain dense matter interactions at intermediate densities.

    Comments:
    17 pages, 8 figures; accepted for publication in the Astrophysical Journal Letters
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2105.06981 [pdf]
    ApJL(2021)·454 citations
  2. 12

    [Submitted on 15 May 2021] (cross-list from hep-ph)

    Delta baryon photoproduction with twisted photons

    Andrei Afanasev🇺🇸 · Carl E. Carlson🇺🇸

    A future gamma factory at CERN or accelerator-based gamma sources elsewhere can include the possibility of energetic twisted photons, which are photons with a structured wave front that can allow a pre-defined large angular momentum along the beam direction. Twisted photons are potentially a new tool in hadronic physics, and we consider here one possibility, namely the photoproduction of (1232) baryons using twisted photons. We show that particular polarization amplitudes isolate the smaller partial wave amplitudes and they are measurable without interference from the terms that are otherwise dominant.

    Comments:
    9 pages, 5 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
    arXiv:
    2105.07271 [pdf]
    Annalen Phys.(2022)·14 citations
  3. 13

    [Submitted on 16 May 2021] (cross-list from cond-mat.quant-gas)

    Bose-Einstein condensation and non-extensive statistics

    E. Megias🇪🇸 · V. S. Timóteo🇧🇷 · A. Gammal🇧🇷 · A. Deppman🇧🇷

    We study the Bose-Einstein condensation in non-extensive statistics for a free gas of bosons, and extend the results to the non-relativistic case as well. We present results for the dependence of the critical temperature and the condensate fraction on the entropic index, q, and show that the condensate can exist only for a limited range of q in both relativistic and non-relativistic systems. We provide numerical results for other thermodynamics quantities like the internal energy, specific heat and number fluctuations. We discuss the implications for high energy physics and hadron physics. The results for the non-relativistic case can be of interest in cold-atom systems.

    Comments:
    18 pages, 11 figures
    Subjects:
    Quantum Gases (cond-mat.quant-gas); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2105.07548 [pdf]
    Physica A: Statistical Mechanics and its Applications(2022)·4 citations
  4. 14

    [Submitted on 14 May 2021] (cross-list from physics.plasm-ph)

    Current-Conserving Relativistic Linear Response for Collisional Plasmas

    Martin Formanek🇺🇸 · Christopher Grayson🇺🇸 · Johann Rafelski🇺🇸 · Berndt Müller🇺🇸

    We investigate the response of a relativistic plasma to electromagnetic fields in the framework of the Boltzmann equation incorporating a collision term in the relaxation rate approximation selected in a form assuring current conservation. We obtain an explicit solution for the linearized perturbation of the Fermi-Dirac equilibrium distribution in terms of the average relaxation rate . We study the resulting covariant, gauge invariant, and current conserving form of the polarization tensor in the ultrarelativistic and non-relativistic limits. We evaluate the susceptibility in the ultrarelativistic limit and explore their dependence on . Finally, we study the dispersion relations for the longitudinal and transverse poles of the propagator. We show that for , where is the plasma frequency, the plasma wave modes are overdamped. In the opposite case, , the propagating plasma modes are weakly damped.

    Comments:
    14 pages, 9 figures
    Subjects:
    Plasma Physics (physics.plasm-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2105.07897 [pdf]
    Annals Phys.(2021)·15 citations
  5. 15

    [Submitted on 17 May 2021] (cross-list from hep-ph)

    QED radiative corrections for accelerator neutrinos

    Oleksandr Tomalak🇺🇸 · Qing Chen🇺🇸 · Richard J. Hill🇺🇸 · Kevin S. McFarland🇺🇸

    Neutrino oscillation experiments at accelerator energies aim to establish charge-parity violation in the neutrino sector by measuring the energy-dependent rate of appearance and disappearance in a beam. These experiments can precisely measure cross sections at near detectors, but cross sections are poorly constrained and require theoretical inputs. In particular, quantum electrodynamics radiative corrections are different for electrons and muons. These corrections are proportional to the small quantum electrodynamics coupling ; however, the large separation of scales between the neutrino energy and the proton mass (), and the electron mass and soft-photon detection thresholds () introduces large logarithms in the perturbative expansion. The resulting flavor differences exceed the percent-level experimental precision and depend on nonperturbative hadronic structure. We establish a factorization theorem for exclusive charged-current (anti)neutrino scattering cross sections representing them as a product of two factors. The first factor is flavor universal; it depends on hadronic and nuclear structure and can be constrained by high-statistics data. The second factor is non-universal and contains logarithmic enhancements, but can be calculated exactly in perturbation theory. For charged-current elastic scattering, we demonstrate the cancellation of uncertainties in the predicted ratio of and cross sections. We point out the potential impact of non-collinear energetic photons and the distortion of the visible lepton spectra and provide precise predictions for inclusive observables.

    Comments:
    8 pages, 5 figures, 1 table; v4: version published in Nature Communications, table 1 corrected, details of factorization and supplementary files added
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2105.07939 [pdf]
    Nature Commun.(2022)·45 citations

Affiliations

first authorsco-authorsvia INSPIRE