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Nuclear Theory·nucl-th

Thursday·February 20, 2025

5 papers—4 primary·1 cross-listed

All5Primary4Cross-lists1
  1. 01

    [Submitted on 18 Feb 2025]

    Non-local high- transport in anisotropic QCD matter

    João Barata🇨🇭 · Xiaojian Du🇪🇸 · Andrey V. Sadofyev🇵🇹

    We perform a numerical study of non-local partonic transport in anisotropic QCD matter, relevant to the evolution of hard probes in the aftermath of high-energy nuclear scattering events. The recently derived master equation, obtained from QFT considerations, differs from Boltzmann transport by incorporating a non-local elastic scattering kernel arising from density gradients. After rewriting the master equation in a form suitable for numerical implementation and assuming a static density profile, we compare the non-local evolution to Boltzmann transport, demonstrating that the new interaction kernel is essential for accurately describing the azimuthal structure of the final-state momentum distribution. We further study the non-local partonic transport in the case of a matter profile governed by two-dimensional hydrodynamics, accounting for its flow and generalizing the evolution equation. Our results demonstrate the necessity of going beyond classical transport at high- to accurately capture the structure of jets propagating through structured QCD matter. The master equation used in the numerical simulations can be seamlessly integrated into state-of-the-art transport codes.

    Comments:
    43 pages, 18 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2502.13205 [pdf]
    PRD(2025)·10 citations
  2. 02

    [Submitted on 19 Feb 2025]

    Perturbative quantum Monte Carlo calculation with high-fidelity nuclear forces

    Jun Liu🇨🇳 · Teng Wang🇨🇳 · Bing-Nan Lu🇨🇳

    Quantum Monte Carlo (QMC) is a family of powerful tools for addressing quantum many-body problems. However, its applications are often plagued by the fermionic sign problem. A promising strategy is to simulate an interaction without sign problem as the zeroth order and treat the other pieces as perturbations. According to this scheme, we construct precision nuclear chiral forces on the lattice and make perturbative calculations around a sign-problem-free interaction respecting the Wigner-SU(4) symmetry. We employ the recently developed perturbative QMC (ptQMC) method to calculate the perturbative energies up to the second order. This work presents the first ptQMC calculations for two-body next-to-next-to-next-to leading order (NLO) chiral forces and elucidates how the hierarchical nature of the chiral interactions helps organize and simplify the ptQMC calculations. We benchmark the algorithm for the deuteron, where exact solutions serve as rigorous reference points. We also reproduce the famous Tjon line by correlating the perturbative He binding energies with the non-perturbative H binding energies. These comprehensive demonstrations underscore the efficacy of ptQMC in resolving high-fidelity nuclear interactions, establishing its potential as a robust tool for \textit{ab initio} nuclear structure studies.

    Comments:
    18 pages, 12 figures, published in Eur. Phys. J. A 61, 85 (2025)
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2502.13565 [pdf]
    EPJA(2025)·13 citations
  3. 03

    [Submitted on 19 Feb 2025]

    Nuclear -cluster structures from valence-space microscopic cluster model

    Zhen Wang · Dong Bai · Zhongzhou Ren

    Alpha clustering is an important dynamic in nuclear physics, with growing interest to its study in heavy nuclei in recent years. Theoretically, the microscopic cluster models taking nucleons as relevant degrees of freedom have been widely used to study -cluster structures in light nuclei. However, a straightforward application on same footing in heavy nuclei is obstructed by the complexity of handling numerous nucleons. As a simplified alternative, the macroscopic cluster models built upon cluster degrees of freedom are usually employed in heavy nuclei, though these approaches typically lose several critical structural details. In this work, we propose to study the -cluster structures within the framework of valence-space microscopic cluster model (VS-MCM), which is a hybrid between microscopic and macroscopic cluster models and inherits features from both models, making it capable to investigate the -cluster structures in heavy nuclei from a relatively microscopic viewpoint. In VS-MCM, the valence clusters are described by antisymmetrized microscopic wave functions, with single-particle orbits in core nuclei removed systematically from the model space via the Pauli projection to simulate the antisymmetrization between clusters and doubly magic cores. As a proof of principle, we apply the VS-MCM to study the -cluster structures in Ne and Ti at first, with the theoretical energy levels of the bands for Ne and Ti showing reasonable agreement with experimental data. These calculations lay the foundation for future applications of VS-MCM in general cluster structures across the nuclide chart, where more clusters and valence nucleons can exist outside the heavy doubly magic core, opening new avenues to study the and cluster decays in heavy nuclei microscopically.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2502.13724 [pdf]
    PLB(2025)·4 citations
  4. 04

    [Submitted on 19 Feb 2025]

    Electromagnetic Radiation from High-Energy Nuclear Collisions

    Charles Gale

    We highlight some of the developments in the theory and the observation of the electromagnetic radiation, thermal and otherwise, emitted in relativistic heavy-ion collisions.

    Comments:
    21 pages, 8 figures. Contribution to "Quark Gluon Plasma at Fifty - A Commemorative Journey", Publisher: Springer Nature Switzerland AG, Editors: Tapan Nayak, Marco Van Leeuwen, Steffen Bass, Claudia Ratti, James Dunlop. Additional material in v2
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2502.13938 [pdf]
    9 citations
  5. 05

    [Submitted on 19 Feb 2025] (cross-list from astro-ph.HE)

    Cross-Comparison of Sampling Algorithms for Pulse Profile Modeling of PSR J0740+6620

    Mariska Hoogkamer · Yves Kini · Tuomo Salmi · Anna L. Watts · Johannes Buchner

    In the last few years, NICER data has enabled mass and radius inferences for various pulsars, and thus shed light on the equation of state for dense nuclear matter. This is achieved through a technique called pulse profile modeling. The importance of the results necessitates careful validation and testing of the robustness of the inference procedure. In this paper, we investigate the effect of sampler choice for X-PSI (X-ray Pulse Simulation and Inference), an open-source package for pulse profile modeling and Bayesian statistical inference that has been used extensively for analysis of NICER data. We focus on the specific case of the high-mass pulsar PSR J0740+6620. Using synthetic data that mimics the most recently analyzed NICER and XMM-Newton data sets of PSR J0740+6620, we evaluate the parameter recovery performance, convergence, and computational cost for MultiNest's multimodal nested sampling algorithm and UltraNest's slice nested sampling algorithm. We find that both samplers perform reliably, producing accurate and unbiased parameter estimation results when analyzing simulated data. We also investigate the consequences for inference using the real data for PSR J0740+6620, finding that both samplers produce consistent credible intervals.

    Comments:
    Published in PRD
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2502.13682 [pdf]
    PRD(2025)·16 citations

Affiliations

first authorsco-authorsvia INSPIRE