Nuclear Theory·nucl-th

Monday·December 22, 2025

14 papers—7 primary·7 cross-listed

01
[Submitted on 19 Dec 2025]
Dynamical equation for quark spin polarization in the rotating medium
Tianyang Li🇨🇳 · Yunfei Fan🇺🇸 · Anping Huang🇨🇳 · Baoyi Chen🇨🇳
In non-central relativistic heavy-ion collisions, the produced quark-gluon plasma (QGP) behaves approximately as a rotating fluid due to the system's initial angular momentum. In this rotating fluid, the spins of quarks become polarized due to the coupling between spin and angular momentum, as well as random spin-spin interactions. Since the Landau-Lifshitz (LL) equation effectively describes the spin polarization of fermions in a medium with a magnetic field, we derive a phenomenological equation analogous to the LL equation for heavy quark spin dynamics in the rotating medium. The spin-angular momentum coupling and random spin-spin interactions are incorporated, leading to a detailed balance of heavy quark spin distributions. This equation provides insight into the spin dynamics of heavy quarks and quarkonium in relativistic heavy-ion collisions.
Comments:
6 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2512.17230 [pdf]
PRD(2026)·1 citation
02
[Submitted on 19 Dec 2025]
Systematic analysis of proton- and deuteron-induced one-proton knockout reactions
Hibiki Nakada · Shoya Ogawa · Yoshiki Chazono · Kazuyuki Ogata
The ratios of the one-proton knockout cross sections by a deuteron to those by a proton are about 1.5, indicating that using deuteron is more efficient than proton in yielding large knockout cross sections. However, this ratio differs from the intuitive expectation, and its underlying mechanism remains unclear. The purpose of this study is to clarify the mechanism behind the observed ratio by theoretically describing and analyzing the deuteron- and proton-induced one-proton knockout reactions. Proton-induced one-proton knockout reactions are described within the standard distorted-wave impulse approximation (DWIA) framework, while deuteron-induced one-proton knockout reactions are treated with a new approach, DWIA-BU, that incorporates deuteron breakup into the DWIA. The ratios calculated with the DWIA-BU reproduce the experimental data reasonably, whereas those with the DWIA significantly underestimate them. The ratio of the corresponding elementary cross sections remains about 3.5 regardless of the energy, and the difference in absorption between the deuteron and the proton influences the ratios of knockout cross sections, resulting in agreement between the calculated ratios and the experimental data. It is found that the deuteron breakup is essential to reproduce the experimental ratio. The ratios of the knockout cross sections are primarily determined by the difference in the elementary cross sections and that in the absorption between the deuteron and the proton.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.17236 [pdf]
J.Phys.Soc.Jap.(2026)·0 citations
03
[Submitted on 19 Dec 2025]
From closed shells to open shells: Coupled-cluster calculations of atomic nuclei
F. Marino🇩🇪 · F. Bonaiti🇺🇸 · P. Demol🇧🇪 · S. Bacca🇩🇪 · T. Duguet🇧🇪 · G. Hagen🇺🇸 · G. R. Jansen🇺🇸 · T. Papenbrock🇺🇸 · A. Tichai🇩🇪
Coupled-cluster theory is a powerful tool for first-principles calculations of atomic nuclei, enabling accurate predictions of nuclear observables across the Segrè chart. While coupled-cluster computations are especially efficient at shell closures, extensions have been developed to tackle open-shell nuclei, by exploiting the equation-of-motion method or by expanding the coupled-cluster wave function on top of a symmetry-breaking (either deformed or superfluid) reference state. In this study, we provide a comprehensive comparison of these different formulations applied to the calcium and nickel isotopes using nuclear two- and three-body interactions from chiral effective field theory. Based on ground-state energies, two-neutron separation energies, and two-neutron shell gaps, different coupled-cluster computations - based on symmetry-broken reference states and equation-of-motion techniques - offer consistent descriptions of bulk properties across medium-mass isotopic chains.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2512.17311 [pdf]
PRC(2026)·6 citations
04
[Submitted on 19 Dec 2025]
Kinetic-Theory Bounds on the Equation of State of Dense QCD Matter
Michał Marczenko🇵🇱
We derive bounds on the equation of state of cold, dense matter by extending the causal, model-agnostic interpolation between chiral effective field theory and perturbative calculations with a microscopic constraint from relativistic kinetic theory. The additional condition restricts the stiffest admissible behavior of the equation of state and systematically reduces the range of allowed equations of state, with the strongest effect at high densities. The resulting bounds remain consistent with known low- and high-density limits, while the strength of the constraint depends on the density above which the kinetic-theory condition is applied. These bounds can be readily incorporated into future studies of cold, dense matter and used to assess the impact of microscopic stability conditions on equation-of-state inference.
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2512.17410 [pdf]
PRC(2026)·1 citation
05
[Submitted on 19 Dec 2025]
Towards a fluid-dynamic description of an entire heavy-ion collision: from the colliding nuclei to the quark-gluon plasma phase
Andreas Kirchner🇺🇸 · Federica Capellino🇩🇪 · Eduardo Grossi🇮🇹 · Stefan Floerchinger🇮🇹
The fluid-dynamical modeling of a nuclear collision at high energy usually starts shortly after the collision. A major source of uncertainty comes from the detailed modeling of the initial state. While the collision itself likely involves far-from-equilibrium dynamics, it is not excluded that a fluid theory of second order can reasonably well describe its soft features. Here we explore this possibility and discuss how the state before the collision can be described in that setup, examine the required fluid-dynamical equations of motion and study the resulting entropy production. While we do here only first steps, we outline a larger program, which could lead to a dynamical description of heavy-ion collisions where the only uncertainty lies in the thermodynamic and transport properties of quantum chromodynamics.
Comments:
Proceedings for Quark Matter 2025
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2512.17651 [pdf]
EPJ Web Conf.(2026)·0 citations
06
[Submitted on 19 Dec 2025]
Reduced basis emulator for elastic scattering in continuum-discretized coupled-channels calculations
Jin Lei
I develop a reduced basis emulator for continuum-discretized coupled-channel (CDCC) calculations that achieves speedups of $\approx 1 0^{2}$ while maintaining sub-percent accuracy. The emulator is constructed using the proper orthogonal decomposition (POD) method applied to snapshots of CDCC solutions computed at sampled points in the optical potential parameter space. The prediction is performed via Galerkin projection onto the reduced basis. I demonstrate the method using deuteron scattering on $^{58}$ Ni at 21.6 MeV as a test case, emulating 18 optical potential parameters simultaneously. The emulator reproduces elastic scattering cross sections with errors below 0.1% across a wide parameter range. This development enables efficient uncertainty quantification and Bayesian parameter estimation for nuclear reaction calculations that were previously computationally prohibitive.
Comments:
12 pages, 7 figures. Published version
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2512.17687 [pdf]
PRC(2026)·7 citations
07
[Submitted on 19 Dec 2025]
Active learning emulators for nuclear two-body scattering in momentum space
A. Giri🇺🇸 · J. Kim🇺🇸 · C. Drischler🇺🇸 · Ch. Elster🇺🇸 · R. J. Furnstahl🇺🇸
We extend the active learning emulators for two-body scattering in coordinate space with error estimation, recently developed by Maldonado et al. [Phys. Rev. C 112, 024002], to coupled-channel scattering in momentum space. Our full-order model (FOM) solver is based on the Lippmann-Schwinger integral equation for the scattering $t$ -matrix as opposed to the radial Schrödinger equation. We use (Petrov-)Galerkin projections and high-fidelity calculations at a few snapshots across the parameter space of the interaction to construct efficient reduced-order models (ROMs), trained by a greedy algorithm for locally optimal snapshot selection. Both the FOM solver and the corresponding ROMs are implemented efficiently in Python using Google's JAX library. We present results for emulating scattering phase shifts in coupled and uncoupled channels and cross sections, and assess the accuracy of the developed ROMs and their computational speedup factors. We also develop emulator error estimation for both the $t$ -matrix and the total cross section. The software framework for reproducing and extending our results is publicly available. Together with our recent advances in developing active-learning emulators for three-body scattering, these emulator frameworks set the stage for full Bayesian calibrations of chiral nuclear interactions and optical models against scattering data with quantified emulator errors.
Comments:
20 pages, 9 figures, 1 Table; minor corrections; close to published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Data Analysis, Statistics and Probability (physics.data-an)
arXiv:
2512.17842 [pdf]
PRC(2026)·2 citations
08
[Submitted on 18 Dec 2025] (cross-list from astro-ph.IM)
ESO Expanding Horizon White Paper: Revealing the properties of matter at supranuclear densities with gravitational waves
Tim Dietrich (1 and 2)🇩🇪 · Tanja Hinderer (3)🇳🇱 · Micaela Oertel (4 and 5)🇫🇷 · Conrado A. Torres (6)🇪🇸 · Nils Andersson (7)🇬🇧 · Dániel Barta (8)🇭🇺 · Andreas Bauswein (9)🇩🇪 · Béatrice Bonga (10 and 11)🇳🇱 · Marica Branchesi (12)🇮🇹 · G. Fiorella Burgio (13)🇮🇹 · Stefano Burrello (14)🇮🇹 · Prasanta Char (6)🇪🇸 and 31 other authors
Understanding dense matter under extreme conditions is one of the most fundamental puzzles in modern physics. Complex interactions give rise to emergent, collective phenomena. While nuclear experiments and Earth - based colliders provide valuable insights, much of the quantum chromodynamics phase diagram at high density and low temperature remains accessible only through astrophysical observations of neutron stars, neutron star mergers, and stellar collapse. Astronomical observations thus offer a direct window to the physics on subatomic scales with gravitational waves presenting an especially clean channel. Next-generation gravitational - wave observatories, such as the Einstein Telescope, would serve as unparalleled instruments to transform our understanding of neutron star matter. They will enable the detection of up to tens of thousands of binary neutron star and neutron star - black hole mergers per year, a dramatic increase over the few events accessible with current detectors. They will provide an unprecedented precision in probing cold, dense matter during the binary inspiral, exceeding by at least an order of magnitude what current facilities can achieve. Moreover, these observatories will allow us to explore uncharted regimes of dense matter at finite temperatures produced in a subset of neutron star mergers, areas that remain entirely inaccessible to current instruments. Together with multimessenger observations, these measurements will significantly deepen our knowledge of dense nuclear matter.
Comments:
5 pages, 2 figures. White paper submitted to ESO Expanding Horizons call
Subjects:
Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2512.16971 [pdf]
0 citations
09
[Submitted on 18 Dec 2025] (cross-list from hep-ph)
The anomalous magnetic moment of the muon: status and perspectives
David W. Hertzog🇺🇸 · Martin Hoferichter🇨🇭
We review the status of the anomalous magnetic moment of the muon as a precision probe of physics beyond the Standard Model (SM) after the release of the final results from the Fermi National Accelerator Laboratory (FNAL) Muon $g - 2$ experiment and the second White Paper of the Muon $g - 2$ Theory Initiative. While the SM prediction requires further improvements by a factor of four to fully leverage the sensitivity achieved in experiment, the FNAL measurement will set the standard for many years to come, and we discuss a variety of features of the experimental campaign that made this achievement possible. In going forward, we discuss current efforts to improve the SM prediction, and imagine how an experiment would have to be devised to surpass 124 ppb in precision.
Comments:
27 pages, 6 figures; in press in the Annual Review of Nuclear and Particle Science
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:
2512.16980 [pdf]
15 citations
10
[Submitted on 18 Dec 2025] (cross-list from hep-ph)
Early-Time Dynamics of Heavy-Ion Collisions through Energy Correlators: celestial blocks and the spacetime structure of out-of-equilibrium QCD matter
João Barata🇨🇭 · José Guilherme Milhano🇵🇹 · Andrey V. Sadofyev🇪🇸 · João M. Silva🇵🇹
Ultrarelativistic heavy-ion collisions provide a unique window into far-from-equilibrium states of QCD matter. The initial stages of these events are characterized by highly anisotropic, nonthermal dynamics that precede hydrodynamization, yet they remain largely inaccessible through conventional soft observables. In this work, we show that the substructure of mid-rapidity jets provides direct sensitivity to the spacetime structure of this early, anisotropic phase. Using classical Yang-Mills simulations and effective kinetic theory to model the early-time evolution of the jet quenching parameter, we compute the azimuthally differential energy-energy correlator within the BDMPS-Z framework. By decomposing the result into celestial blocks, we isolate the coefficients that encode the anisotropic geometry and dynamics of the underlying medium. We identify an observable that couples directly to spatial anisotropies in the out-of-equilibrium QCD matter and also discuss the impact of medium response on its behavior. We further extend our study to mid-rapidity jets generated with the JEWEL Monte-Carlo, adjusted to incorporate an anisotropic medium background, and find qualitative agreement with the analytical expectations. Finally, we discuss how higher-point energy correlators and generalized energy-flow operators can enhance the sensitivity to the microscopic structure of far-from-equilibrium QCD matter.
Comments:
17 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2512.17009 [pdf]
13 citations
11
[Submitted on 19 Dec 2025] (cross-list from hep-ph)
A Brief History and Outlook of Hadronic Physics in Indonesia
Ahmad Jafar Arifi🇯🇵 · Parada. T. P. Hutauruk🇰🇷 · Terry Mart🇮🇩 · Chalis Setyadi🇮🇩
Hadronic physics has gradually emerged as one of the growing research frontiers in Indonesia, driven by efforts to better understand the properties of the strong interaction and the internal structure of hadrons from the fundamental principles of Quantum Chromodynamics. In the last few decades, Indonesian researchers have made significant contributions to developing various theoretical and phenomenological aspects of hadrons. In addition, on the experimental side, Indonesian scientists have participated in hadron experiment facilities overseas, such as the ALICE collaboration at CERN, which has strengthened the scientific activities and networks and has supported the training of young Indonesian researchers. In the present paper, we review Indonesian scientists' contributions to hadronic physics, highlight ongoing research directions in both experimental and theoretical, and outline strategies for future development toward integration into the international hadronic physics community.
Comments:
17 pages, 3 figures, contribution to the SEA-NHP 2025, submitted to Modern Physics Letters A
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); physics.soc-ph (physics.soc-ph)
arXiv:
2512.17219 [pdf]
0 citations
12
[Submitted on 19 Dec 2025] (cross-list from hep-ph)
Evidence for dynamical chiral condensate in high-energy heavy ion collisions
Tobias Bruschke🇩🇪 · Andreas Kirchner🇺🇸 · Stefan Floerchinger🇩🇪
Quantum chromodynamics with light quarks features an approximate global symmetry, known as chiral symmetry, that is believed to be spontaneously broken by the vacuum expectation value of a scalar and isoscalar composite field, in addition to a small explicit breaking due to finite quark masses. For a high enough temperature, as achieved in the early universe or the fireball created by a high-energy heavy ion collision, this symmetry is expected to be restored. We show theoretically that a coherent deviation of the corresponding quantum field from its usual vacuum expectation value on the freeze-out hypersurface of a heavy-ion collision leads, after resonance decays, to a characteristic contribution to the transverse momentum spectrum of charged pions, in the very soft regime, consistent with experimental data from the Relativistic Heavy Ion Collider and the Large Hadron Collider. Taken together, the experimental data with the new theoretical results provide compelling support for the existence of a chiral condensation mechanism with partial restoration of chiral symmetry at high temperature.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2512.17413 [pdf]
1 citation
13
[Submitted on 19 Dec 2025] (cross-list from hep-ph)
Unified study of $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ and $B_{s}^{0} \to ψ (2 S) π^{+} π^{-} (K^{+} K^{-})$ processes
Yun-Hua Chen🇨🇳
We perform a unified description of the experimental data of the $π^{+} π^{-}$ invariant mass spectra of $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ , the $π^{+} π^{-}$ and $K^{+} K^{-}$ invariant mass spectra of $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ , and the ratio of branch fractions $B [B_{s}^{0} \to X (3872) (K^{+} K^{-})_{non - ϕ}] / B [B_{s}^{0} \to X (3872) π^{+} π^{-})$ . The strong final state interactions between the two pseudoscalars are taken into account using a parametrization fulfilling unitarity and analyticity. We find that there is universality in the coupling constants for $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ and $B_{s}^{0} \to J / ψ π^{+} π^{-}$ processes. While the couplings of $B_{s}^{0} \to X (3872) π^{+} π^{-}$ are about half of magnitude smaller than the couplings of $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ , which indicates that the $X (3872)$ is different from a pure charmonium state. Furthermore, we find that the $f_{0} (1500)$ plays an important role in the $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ and the $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ processes, though the phase space of $B_{s}^{0} \to X (3872) f_{0} (1500)$ is small. Also we predict the ratio of branch fractions $B [B_{s}^{0} \to ψ (2 S) (K^{+} K^{-})_{non - ϕ}] / B [B_{s}^{0} \to ψ (2 S) π^{+} π^{-}]$ and the $K^{+} K^{-}$ invariant mass distribution of $B_{s}^{0} \to ψ (2 S) K^{+} K^{-}$ .
Comments:
15 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2512.17754 [pdf]
EPJC(2026)·0 citations
14
[Submitted on 19 Dec 2025] (cross-list from hep-ph)
From Lead to Helium: Discovery Potential for Jet Quenching in the Smallest Collision Systems
Coleridge Faraday🇿🇦 · Ben Bert🇿🇦 · Jack Brand🇿🇦 · Werner Vogelsang🇩🇪 · W. A. Horowitz🇿🇦
We present perturbative quantum chromodynamics (pQCD) predictions for the modification to the yield of high-momentum particles in very light ion collisions - $^{10} B +^{10} B$ , $^{6} Li +^{6} Li$ , $^{4} He +^{4} He$ , and $^{3} He +^{3} He$ - both with and without medium-induced energy loss. We show that there is non-trivial suppression expected from our partonic energy loss model in symmetric systems from $^{208} Pb +^{208} Pb$ to $^{3} He +^{3} He$ and in asymmetric systems $A + B$ , and that the energy loss scales approximately with $(A B)^{1/3}$ . Further, we find that deep inelastic scattering measurements in $^{3} He$ and $^{6} Li$ tightly constrain the nPDF baseline, making these isotopes a particularly clean environment for observing final-state partonic energy loss induced by the formation of a quark-gluon plasma in these very small systems.
Comments:
7 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2512.17832 [pdf]
4 citations

Affiliations

first authorsco-authorsvia INSPIRE