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Nuclear Theory·nucl-th

Wednesday·September 2, 2026

14 papers—7 primary·7 cross-listed

All14Primary7Cross-lists7
  1. 08

    [Submitted on 31 Aug 2026] (cross-list from hep-ph)

    Magnetic field-induced enhancement and quenching of Urca emission in quark matter

    William Gyory🇺🇸 · Igor A. Shovkovy🇺🇸

    Using first-principles field-theoretic methods, we investigate neutrino emission from strongly magnetized dense quark matter under conditions relevant to compact stars. We account for Landau-level quantization of both electron and quark states and show that it strongly modifies the kinematics of Urca processes. In particular, quark quantization restricts the available phase space in which both quark and electron energies can simultaneously lie near their respective Fermi surfaces. At moderately strong magnetic fields, before pronounced quark quantization sets in, the emission rate tends to increase on average with increasing field strength. In the regime of very strong fields, however, the increasingly restricted phase space first gives rise to Shubnikov--de Haas-type oscillations and then to resonance-like spikes near a discrete sequence of Urca-resonant magnetic field values, separated by regions of strong suppression. Finally, the emission rate becomes nearly completely quenched once , corresponding to approximately for the representative set of model parameters considered. We also find significant anisotropy in the longitudinal momentum emission near the Urca-resonant magnetic field values.

    Comments:
    33 pages, 8 multipanel figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2609.00157 [pdf]
    0 citations
  2. 09

    [Submitted on 31 Aug 2026] (cross-list from astro-ph.HE)

    A NICER view of PSR J16142230: a massive and compact millisecond pulsar

    Lucien Mauviard · Sebastien Guillot · Lami Suleiman · Yves Kini · Denis González-Caniulef · Christine Kazantsev · Pierre Stammler · Devarshi Choudhury · Bas Dorsman · Mariska Hoogkamer · Daniela Huppenkothen · Tuomo Salmi and 8 other authors

    Using pulse profile modeling, we obtain the mass-radius measurement of a millisecond pulsar (MSP) with data from the Neutron Star Interior Composition ExploreR, XMM-Newton and the Chandra X-ray Observatory. We report here the radius of PSR J16142230, the second most massive MSP confirmed by radio timing. All of the data sets are well described by a simple model composed of two circular hot spots. The final result yields an equatorial radius of km, and a gravitational mass of (equally tailed 68% credible intervals). Although a non-thermal component was previously reported at higher energies, we find no sign of it in either our phase-averaged or phase-resolved spectral analyses. Using new relations linking the compactness to oblateness or surface gravity, and tailored to the spin frequency of PSR J16142230, we infer a configuration with one hot spot near the pole, and another near the equator. The tight mass posterior is essentially informed by radio timing, while the radius constraint is not as tight due to the low source signal (8.5 X-ray pulse significance). However, over all geometries and atmosphere models tested, the radius posterior tends toward low values (km, 90th percentile in all cases).

    Comments:
    27 pages, 11 figures and 5 tables. Submitted to ApJ. Data files available in Zenodo
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2609.00172 [pdf]
    0 citations
  3. 10

    [Submitted on 31 Aug 2026] (cross-list from astro-ph.HE)

    Equation of state and neutron star properties with new mass-radius constraints from PSR~J1614--2230, PSR~J2124--3358, and 47~Tuc~X7

    Melissa Mendes · Isak Svensson · Hannah Gottling · Kai Hebeler · Achim Schwenk · Nathan Rutherford · Lucien Mauviard · Christine Kazantsev · Yves Kini · Denis Gonzalez-Caniulef · Sebastien Guillot · Anna Watts

    We study the impact of new mass-radius information from PSR J1614-2230, PSR J2124-3358, and 47 Tuc X7 in a combined equation of state inference based on chiral effective field theory constraints at nuclear densities and using different high-density extensions, including perturbative QCD constraints. The largest impact stems from the heavy-mass PSR J1614-2230 star, which shifts heavy neutron stars to smaller radii by around 0.4 km. Moreover, the combined astrophysical NICER, LIGO/Virgo, and X-ray information drives the radius posterior to a more data-driven distribution, which is less sensitive to the high-density extension. For the equation of state, the new mass-radius information significantly tightens the pressure and speed-of-sound posterior distributions, especially around three times saturation density. Finally, we make predictions for the poorly constrained masses of PSR J2124-3358 and 47 Tuc X7 based on the combined equation of state analysis and the other astrophysical sources.

    Comments:
    13 pages, 9 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2609.00173 [pdf]
    0 citations
  4. 11

    [Submitted on 31 Aug 2026] (cross-list from astro-ph.SR)

    A Data-Driven Model for -Process Production Patterns

    Chen-Qi Li · Yong-Zhong Qian · Axel Gross · Zewei Xiong

    Using the elemental abundances in 68 metal-poor (MP) stars, we present a data-driven model for -process production patterns covering Sr to U. We show that essentially all the -process patterns in those and other test stars can be adequately explained as mixtures of Patterns 1 and 2, which provides theoretical insights into the empirical categories of limited-, -I, and -II stars. We carry out an extensive survey of the yield templates produced by parametric -process calculations. We propose that Pattern 2 may be dominated by a single template and points to regularity in -process production by a subset of neutron star mergers (NSMs), while Pattern 1 is the average superposition of multiple templates and reflects production by other NSMs and perhaps also some magneto-rotational supernovae. We raise possible systematic issues with abundance ratios for elements measured in different ionization states, and highlight the need for examining the Os, Ir, and Pt measurements for HD~122563, which is dominated by Pattern 1 with a prominent Pt peak in our model. If this result is confirmed, the meaning of the limited- category requires drastic revision. Further measurements of a wider range of -process elements in a larger sample of MP stars are critical to test and improve our model.

    Comments:
    Accepted for publication in The Astrophysical Journal (ApJ), 48 pages
    Subjects:
    Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2609.00303 [pdf]
    0 citations
  5. 12

    [Submitted on 1 Sept 2026] (cross-list from hep-ph)

    Investigating three-body resonances in clusters within the nucleus

    Hao Zhou🇨🇳 · Xiang Liu🇨🇳

    We investigate the bound and resonant states of the and three-body systems, corresponding to and , within the Gaussian expansion method combined with the complex scaling method. The and interactions are constructed by folding the and potentials obtained from lattice QCD calculations by the HAL QCD Collaboration with the nucleon density distribution of the particle. The uncertainty associated with the -particle matter radius is also examined. For the sector, the strong attraction generates deeply bound , , and states in , accompanied by a pronounced contraction of the core, demonstrating a strong gluelike effect of the baryon. An unconventional inversion between the and levels is also predicted. In contrast, the baryon produces considerably weaker attraction: the state of is weakly bound, whereas the and states remain resonances. Their resonance energies and widths exhibit a clear dependence on the strength of the interaction. These results reveal qualitatively different gluelike behaviors of the and baryons and provide predictions for the spectroscopy of exotic multistrange and triply charmed hypernuclei.

    Comments:
    13 pages, 6 figures and 3 tables
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2609.00932 [pdf]
    0 citations
  6. 13

    [Submitted on 1 Sept 2026] (cross-list from astro-ph.HE)

    The Radius of the Neutron Star PSR J0614-3329 from NICER Data

    M. C. Miller · A. J. Dittmann · I. M. Holt · F. K. Lamb · C. Chirenti · Z. Arzoumanian · J. Berteaud · S. Bogdanov · K. C. Gendreau · A. K. Harding · W. C. G. Ho · C. Kalapotharakos and 5 other authors

    Neutron star radius measurements, particularly using X-ray data collected with the Neutron star Interior Composition Explorer (NICER), have provided invaluable information for models of cold, catalyzed matter at densities above that of nuclear saturation. Here we present an analysis of NICER data on the 318-Hz pulsar PSR J0614-3329, which has a mass ~1.4-1.5 solar masses determined from radio observations. The best-fitting model we explore has three uniform-temperature circular hot spots and yields a symmetric 68% credible range for the equatorial circumferential radius of 9.88-12.77 km. We also explore joint fits to the NICER data and the X-ray Multi-Mirror (XMM-Newton) data on this pulsar, but find that the models that best fit both data sets systematically underpredict the XMM-Newton data when, as is standard, it is assumed that the XMM-Newton background is known from observations of surrounding fields. Finally, we discuss the implications of our results, combined with data on other neutron stars, for the properties of the dense matter in neutron star cores.

    Comments:
    15 pages, 8 figures, submitted to The Astrophysical Journal. Posterior samples available on Zenodo via doi:10.5281/zenodo.22131748
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    2609.00965 [pdf]
    0 citations
  7. 14

    [Submitted on 1 Sept 2026] (cross-list from hep-ph)

    Amplitude structure of scattering in a Mandelstam variable representation

    Xu Zhang · Feng-Kun Guo

    We construct a dispersive representation of the relativistic scattering amplitude for three identical spinless particles in the -wave. The two-particle subenergy, instead of the total energy, is used as the dispersive variable. This choice keeps the physical dispersive contour free of the kinematical cuts that complicate total-energy dispersion relations. By separating discontinuities across the two-particle subenergy cuts from that across the three-body cut, we derive a linear integral equation with one-particle exchange as the driving term. We further show that the solution satisfies three-body unitarity as a consequence of two-body unitarity, analyticity, and crossing symmetry. For pair-wise interactions, this representation can be rewritten into the form used for isobar-spectator scattering. Finally, we give prescriptions for contour deformation and the subtraction of poles in the two-body subsystem amplitudes, which continue the amplitude onto adjacent unphysical Riemann sheets and thus provide direct access to the analytic structure relevant for three-body resonance poles.

    Comments:
    15 pages, 5 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2609.00985 [pdf]
    0 citations

Affiliations

first authorsco-authorsvia INSPIRE