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Nuclear Theory·nucl-th

Monday·July 14, 2025

7 papers—4 primary·3 cross-listed

All7Primary4Cross-lists3
  1. 01

    [Submitted on 10 Jul 2025]

    Conformal prediction for uncertainties in nucleon-nucleon scattering

    Habib Yousefi Dezdarani🇨🇦 · Ryan Curry🇨🇦 · Alexandros Gezerlis🇨🇦

    Conformal prediction is a distribution-free and model-agnostic uncertainty-quantification method that provides finite-sample prediction intervals with guaranteed coverage. In this work, for the first time, we apply conformal-prediction to generate uncertainty bands for physical observables in nuclear physics, such as the total cross section and nucleon-nucleon phase shifts. We demonstrate the method's flexibility by considering three scenarios: (i) a pointwise model, where expansion coefficients in chiral effective field theory are treated as random variables; (ii) a Gaussian-process model for the coefficients; and (iii) phase shifts at various energies and partial waves calculated using local interactions from chiral effective field theory. In each case, conformal-prediction intervals are constructed and validated empirically. Our results show that conformal prediction provides reliable and adaptive uncertainty bands even in the presence of non-Gaussian behavior, such as skewness and heavy tails. These findings highlight conformal prediction as a robust and practical framework for quantifying theoretical uncertainties.

    Comments:
    15 pages, 18 figures; v3 corresponds to published version
    Subjects:
    Nuclear Theory (nucl-th); Data Analysis, Statistics and Probability (physics.data-an)
    arXiv:
    2507.08085 [pdf]
    PRC(2026)·4 citations
  2. 02

    [Submitted on 10 Jul 2025]

    Evaluation of bound-state -decay half-lives of fully ionized atoms

    Priyanka Choudhary · Chong Qi

    Bound-state -decay is a rare radioactive process where the created electron is trapped in an atomic orbital instead of being emitted. It can be observed in highly ionized atoms in particular when normal beta decay is energetically forbidden, but bound-state decay is still possible. In this work we present a systematic theoretical study on the bound-state -decay of fully ionized atoms where key nuclear inputs include the nuclear matrix elements (expressed through values) and the lepton phase-space volume function. We present a method to evaluate nuclear matrix elements for fully forbidden transitions in neutral atoms, from the inverse electron capture process using the Takahashi-Yokoi model and account for the impact of electron capture to different atomic orbitals on the resulting half-lives. Decay rates for bound-state -decays of nuclei Dy, Ir, Au, Tl, Tl, At, Rn, Am, and Bk are calculated, where the normal beta decay is forbidden. In addition, we compute the bound-state decay rates for nuclei Re, Ac, and Ra, observing enhancements by factors of to relative to their neutral-atom counterparts. Our results show that the half-lives of certain bare nuclei are significantly shorter than those of the corresponding neutral atoms, identifying them as promising candidates for future experimental investigation. The theoretically predicted half-lives of the bound-state decay could provide valuable inputs for various astrophysical studies.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2507.08199 [pdf]
    EPJA(2026)·1 citation
  3. 03

    [Submitted on 11 Jul 2025]

    Ab initio lattice study of neutron-alpha scattering with chiral forces at N3LO

    Serdar Elhatisari · Fabian Hildenbrand · Ulf-G. Meißner

    We present the first ab initio lattice calculation of neutron-alpha (-) scattering using nuclear lattice effective field theory (NLEFT) with chiral interactions at next-to-next-to-next-to-leading order (N3LO). Building on the high-fidelity chiral Hamiltonian introduced in Ref. [1], we compute scattering phase shifts in the - and -wave channels using the Lüscher finite-volume method. Our results demonstrate excellent agreement with empirical -matrix phase shifts in the and channels, while revealing persistent discrepancies in the channel for neutron energies above 5 MeV. To systematically investigate these discrepancies, we construct and analyze a simplified neutron-alpha toy model, demonstrating that these discrepancies are not due to the use of the Lüscher finite-volume method. Additionally, we revisit our three-nucleon (3N) force fitting procedure, explicitly incorporating neutron-alpha scattering data through comprehensive Markov Chain Monte Carlo (MCMC) sampling. This analysis confirms the stability of nuclear binding-energy predictions and highlights the need for further refinements in the lattice N3LO three-nucleon forces to fully describe neutron-alpha scattering in the challenging channel.

    Comments:
    22 pages, 6 figures, 2 tables
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex)
    arXiv:
    2507.08495 [pdf]
    J.Phys.G(2025)·12 citations
  4. 04

    [Submitted on 11 Jul 2025]

    The breakdown scale of pionless effective field theory in the three-nucleon sector

    Andreas Ekström🇸🇪 · Lucas Platter🇺🇸

    We make order-by-order predictions of neutron-deuteron total cross sections up to next-to-next-to-leading order in pionless effective field theory. Using Bayesian methods, we infer a posterior distribution for the breakdown scale. The result shows a mode near 100 MeV, and a combined analysis with neutron-proton scattering further sharpens the inference, placing the mode close to the pion mass scale, consistent with the expected range of pionless effective field theory.

    Comments:
    6 pages, 5 figured
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2507.08700 [pdf]
    PRC(2025)·4 citations
  5. 05

    [Submitted on 10 Jul 2025] (cross-list from hep-ph)

    Chiral and deconfinement transitions in spin-polarized quark matter

    Ricardo L. S. Farias🇧🇷 · William R. Tavares🇧🇷

    We investigate the influence of spin polarization in strongly interacting matter by introducing a finite spin potential, , which effectively controls the spin density of the system without requiring rotation or specific boundary conditions. Inspired by recent lattice QCD simulations that incorporated such a potential, we implement this approach within an effective QCD framework. Our results show that increasing spin polarization leads to a simultaneous decrease in both the chiral and deconfinement restoration temperatures. The resulting phase structure is qualitatively consistent with lattice findings, and notably, we observe the emergence of a first-order chiral phase transition at low temperature. These results suggest that spin-polarized environments can significantly impact the QCD phase diagram and offer a controlled route for studying spin effects in hot and dense matter.

    Comments:
    Some typos have been corrected and comments have been added. Matches the version accepted in Physical Review D
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2507.08130 [pdf]
    PRD(2025)·5 citations
  6. 06

    [Submitted on 11 Jul 2025] (cross-list from hep-ph)

    Hadron-Hadron Interactions from Lattice QCD: Theory meets Experiments

    Tetsuo Hatsuda🇯🇵

    We summarize recent developments in the study of hadron-hadron interactions using lattice QCD near the physical pion mass ( MeV), based on the HAL QCD method and its connection to experimental data. In particular, we focus on several key interaction channels shown below. Also, we examine the two-pion exchange (TPE) mechanism, which governs the long-range behavior of interactions between flavor-singlet hadrons, as well as between nucleons and flavor-singlet hadrons.

    Comments:
    19 pages, 9 figures. Plenary talk at the XVIth Quark Confinement and the Hadron Spectrum Conference (QCHSC24) 19-24 August, 2024 (Cairns, Australia)
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2507.08359 [pdf]
    PoS(2025)·3 citations
  7. 07

    [Submitted on 11 Jul 2025] (cross-list from hep-ph)

    Spectroscopic and femtoscopic insights into vector-baryon interactions in the strangeness sector

    P. Encarnación🇪🇸 · M. Albaladejo🇪🇸 · A. Feijoo🇪🇸 · J. Nieves🇪🇸

    We revisit the strangeness sector of the interaction between vector mesons of the nonet and ground state baryons (), within the unitary coupled-channel hidden gauge formalism. We adopt a renormalization scheme that induces a reasonable short-distance behavior of the two-hadron wave functions, which is the major limitation of femtoscopy techniques at this time. We perform an exhaustive spectroscopy study, implementing different improvements and considerations, and find compatibilities between the poles extracted from the present approach, and some of the states listed in the Review of Particle Physics. Finally, we predict several correlation functions (CFs) associated with various meson-baryon pairs in this sector, paying special attention to the distinctive and clear signatures produced by the dynamically generated states. To obtain realistic estimates for the CFs, we have calculated the production weights using the Thermal-FIST package. Such studies will shed light into the odd-parity and hadron spectra, up to 2 GeV, and will open the strategy to improve effective field theories by using low-energy constants fitted to femtoscopy data.

    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2507.08466 [pdf]
    EPJC(2025)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE