Nuclear Theory·nucl-th

Tuesday·September 16, 2025

14 papers—5 primary·9 cross-listed

01
[Submitted on 12 Sept 2025]
Theoretical Signatures of QCD Phase Transitions in Compact Astrophysical Systems
Debarshi Mukherjee🇮🇳
We investigate theoretical signatures of first-order QCD phase transitions in high-density astrophysical systems through a framework combining lattice QCD, effective field theories, and multimessenger constraints. Hybrid equations of state with Maxwell and Gibbs constructions, constrained by lattice QCD at finite temperature and baryon chemical potential up to mu_B/T < 3, interpolate consistently between chiral effective field theory at nuclear densities and perturbative QCD at asymptotic densities. Applying these models to static neutron stars via Tolman-Oppenheimer-Volkoff equations and to binary mergers via relativistic hydrodynamics, we find distinctive signatures: (i) twin star branches with 0.5-2.0 km radius differences at fixed mass, (ii) equation of state softening in coexistence regions reducing maximum masses by 0.2-0.4 solar masses, (iii) delayed post-merger gravitational-wave frequency shifts of 200-400 Hz, and (iv) enhanced neutrino emission during phase transitions. Confronted with multimessenger constraints from GW170817, NICER observations of PSR J0740+6620 and PSR J0030+0451, and perturbative QCD, our models suggest strong first-order transitions are marginally consistent with current data but produce signatures detectable by next-generation detectors. Neutron star core sound speeds satisfy c_s^2 < 0.5c^2, with transient conformal bound violations in 2-4 times saturation density. This framework yields quantitative predictions for the Einstein Telescope and Cosmic Explorer, establishing foundations for precision QCD matter tests and possible quark matter discovery.
Comments:
This manuscript is being withdrawn by the author because it does not meet the scientific standards the author wishes to maintain in the permanent literature. The results and presentation are considered preliminary and should not be cited
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Lattice (hep-lat)
arXiv:
2509.10589 [pdf]
0 citations
02
[Submitted on 12 Sept 2025]
SIV Guided Resolution of the Lithium-7 BBN Problem
Vesselin G. Gueorguiev🇧🇬
A possible resolution of the $^{7}$ Li problem within the Standard Model Big-Bang Nucleosynthesis is presented. The key idea originates from the application of the Scale-Invariant Vacuum (SIV) paradigm to the BBN. However, here we arrive at the conclusion that Reparametrization Invariant Symmetry Scaling (RISS) is the more appropriate framework for the epoch of the BBN and use the SIV only as a guidance framework. The outcome is $χ^{2} < 0.04$ fit to the observed primordial abundances of $^{4}$ He, D/H, $^{3}$ He/D, and fit of $χ^{2} \approx 1$ when including $^{7}$ Li/H observations. The results are obtained and compared to the known standard BBN values by utilizing the publicly available PRIMAT code. The resolution of the $^{7}$ Li problem requires SIV-guided deviation from the local thermal equilibrium during BBN, such that the thermal energy of matter and radiation scale differently with respect to the SIV-conformal factor $λ$ during the BBN epoch. This may be viewed as conformal symmetry breaking due to cooling of plasma and the properties of matter. As such, the framework may be of relevance to the problem of the nuclear fusion as well. The deduced baryon matter content is $Ω_{b} \approx 12%$ for unbroken SIV and $Ω_{b} \approx 38%$ for partially broken SIV, but with $λ < 1$ in both cases, which signals preference for Reparametrization Invariant Symmetry Scaling (RISS) over the conventional SIV viewpoint. Applying the RISS paradigm results in $λ > 1$ and $Ω_{b} \approx 10%$ with clear departure of $n_{T}$ away from the naive SIV suggested value. In all the cases where the $^{7}$ Li problem is resolved, the baryon content is significantly higher than the usually accepted value of $Ω_{b} \approx 4.9%$ within the $Λ$ CDM. \keywords{Cosmology -- Primordial Nucleosynthesis -- dark matter, Reparametrization Invariance, Scale-Invariant Vacuum (SIV)}
Comments:
4 pages, two column text, 1 figure and 1 table, to appear in A&A as letter article
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2509.10721 [pdf]
Astron.Astrophys.(2025)·0 citations
03
[Submitted on 14 Sept 2025]
Data-driven trap theory for nuclear scattering
Hantao Zhang · Dong Bai · Xilin Zhang · Zhongzhou Ren
We present a novel data-driven trap theory (abbreviated as DDTT) for nuclear scattering, which aims to overcome the limitations of the traditional trap method in dealing with narrow potential wells, while also providing a more efficient framework for handling long-range Coulomb interactions. As proof-of-concept examples, we employ this unified theory to analyze the elastic scattering of nucleon-nucleon and nucleon-{\alpha} systems. DDTT can successfully produce results consistent with those from traditional approaches, highlighting its significance for ab initio light nuclei scattering studies and potential for applications in the heavier mass region.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2509.11072 [pdf]
0 citations
04
[Submitted on 14 Sept 2025]
Few-Nucleon Systems within Finite-Cutoff Pionless EFT
Liron H. Avraham🇮🇱 · Betzalel Bazak🇮🇱
We investigate pionless effective field theory (\nopieft) with finite-cutoff regularization as a framework for describing few-nucleon systems. This formulation incorporates effective-range effects already at leading order (LO), thereby reaching next-to-leading-order (NLO) accuracy while maintaining computational efficiency. Using correlated-Gaussian stochastic variational methods in a weak harmonic-oscillator trap, together with neutral and Coulomb-modified quantization conditions, we calculate binding energies and low-energy $S$ -wave scattering parameters for systems with up to five nucleons. At an optimal cutoff, the computed binding energies of the deuteron, triton, helion, and alpha particle reproduce experimental values at the percent level once a three-body force is included. Scattering parameters for proton--proton, nucleon--deuteron, nucleon--triton, proton--helion, deuteron--deuteron, and nucleon--alpha channels are obtained and found to be consistent with both experimental data and existing NLO \nopieft\ calculations. These results demonstrate that finite-cutoff \nopieft\ offers a robust and predictive framework for few-body nuclear physics.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2509.11180 [pdf]
PLB(2026)·5 citations
05
[Submitted on 15 Sept 2025]
Nuclear transitions on demand
C.-J. Yang
I show a way to tune photo-nuclear cross section effectively and therefore achieve nuclear transitions "on demand". The method is based on combinatorial enhancement of multiphoton processes under intense conditions. Taking advantage of recent advances in high-power laser systems (HPLS) and nuclear structure calculations, efficient control of nuclear transitions up to E4 in multipolarity can be reached today. The same idea can be extended to the search for rare transitions and hidden states, which applies to the $γ$ -beams generated from conventional sources as well.
Comments:
7 pages, 5 figures, to appear in the Proceedings of the 14th Int. Spring Seminar on Nuclear Physics: "Cutting-edge developments in nuclear structure physics", one new figure added
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2509.11794 [pdf]
EPJ Web Conf.(2025)·0 citations
06
[Submitted on 12 Sept 2025] (cross-list from hep-lat)
Renormalization Group Approach to Confinement
Gerrit Schierholz🇩🇪
While we have several complementary models of confinement, some of which are phenomenologically appealing, we do not have the ability to calculate analytically even simple aspects of confinement, let alone have a framework to eventually prove confinement. The problem we are facing is to evolve the theory from the perturbative regime to the long distance confining regime. This is generally achieved by renormalization group transformations. With the gradient flow we now have a technique to address the problem from first principles. The primary focus is on the running coupling $α_{S} (μ)$ , from which confinement can be concluded alone. A central point is that the gluon condensate is scale invariant, which reflects its self-similar behavior across different scales. Building on that, we derive $α_{S} (μ) ≃ Λ_{S}^{2} / μ^{2}$ , which evolves to the infrared fixed point $1/ α_{S} = 0$ in accordance with infrared slavery. The only important factor appears to be the presence of the gluon condensate, which is a universal feature that QCD shares with many other models. The analytical results are supported by numerical simulations.
Comments:
17 pages, 6 figures, some improvements to the text, matches published version
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2509.10658 [pdf]
EPJC(2026)·1 citation
07
[Submitted on 12 Sept 2025] (cross-list from hep-ph)
Glauber quark and gluon contributions to quark energy loss at next-to-leading order and next-to-leading twist
Amit Kumar🇨🇦 · Gojko Vujanovic🇨🇦
The higher-twist formalism is used at $O (α_{s}^{2})$ to compute all possible medium-induced single-scattering emission kernels for an incoming highly energetic and virtual quark traversing the nuclear environment. The effects of the heavy-quark mass scale are taken into account [Phys. Rev. C 94, 054902 (2016)] both in the initial state as well as in the final state, along with interactions involving both in-medium Glauber gluons and quarks [Nucl. Phys. A 793, 128 (2007)], as well as coherence effects [Phys. Rev. C 105, 024908 (2022)]. As this study is a continuation of our work on medium-induced photon production [Phys. Rev. C 112, 025204 (2025)], the general factorization procedure for $e$ - $A$ deep-inelastic scattering is still used. An incoming quark energy loss in the nuclear medium yields four possible scattering kernels $K_{i}$ with the following final states: (i) $q + g$ , (ii) $g + g$ , (iii) $q + q ˉ^{'}$ , where the quark $q$ may have a flavor different from the antiquark $q ˉ^{'}$ , and (iv) $q + q^{'}$ , where, again, $q$ may have a flavor different from $q^{'}$ . The collisional kernels include full phase factors from all non-vanishing diagrams and complete first-order derivative in the longitudinal direction ( $k^{-}$ ) as well as second-order derivative in the transverse momentum ( $k_{⊥}$ ) gradient expansion. Furthermore, in-medium parton distribution functions and the related jet transport coefficients have a hard transverse-momentum dependence (of the emitted quark or gluon) present within the phase factor.
Comments:
66 pages, 23 figures, single column; Updated introduction and discussion; Matched to published version [Phys. Rev. C 113, 055207 (2026)]
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2509.10743 [pdf]
PRC(2026)·4 citations
08
[Submitted on 13 Sept 2025] (cross-list from hep-ph)
Collective motion in the massive Schwinger model via Tensor Network
Haiyang Shao🇨🇳 · Shile Chen🇨🇳 · Shuzhe Shi🇨🇳
We simulate the real-time dynamics of a massive Schwinger model using the Time-Evolving Block Decimation tensor network algorithm. Starting from a non-equilibrium initial state with localized energy excitation on top of vacuum, we track the subsequent evolution to investigate two distinct physical phenomena. First, by analyzing the system's energy-momentum tensor, we show that this system exhibits hydrodynamic behavior analogous to Bjorken flow at large coupling-to-mass ratio, a signature that diminishes as the coupling weakens, or mass increases. Second, by examining the evolution of the electric field and charge density, we observe the signal of spontaneous parity symmetry breaking phase transition in a dynamical system. The parity-restored regime is marked by ''string breaking'' and efficient charge screening, while the parity-broken regime displays stable propagation of nearly free charges and persistent electric fields connecting them.
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2509.10835 [pdf]
5 citations
09
[Submitted on 13 Sept 2025] (cross-list from hep-ph)
Onset of Bjorken Flow in Quantum Evolution of the Massive Schwinger Model
Haiyang Shao🇨🇳 · Shile Chen🇨🇳 · Shuzhe Shi🇨🇳
The onset of hydrodynamics in the hot medium created in relativistic heavy-ion collisions is a crucial theoretical question. A first-principle simulation requires a real-time, non-perturbative calculation of the quantum system. In this Letter, we perform such simulations using the tensor network method, which enables large-scale quantum many-body simulations by retaining only the most essential quantum states for collective behaviors. We focus on the massive Schwinger model, a low-dimensional analog of quantum chromodynamics (QCD), as they share important properties such as confinement and chiral symmetry breaking. Starting from an initial state that puts a localized excitation atop the vacuum and mimics the energy deposition from colliding nuclei, we observe hydrodynamic behavior consistent with Bjorken flow in all relevant degrees of freedom: energy density, fluid velocity, and bulk pressure. The time scale for hydrodynamic onset aligns with the thermalization time of the quantum distribution function.
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2509.10855 [pdf]
9 citations
10
[Submitted on 14 Sept 2025] (cross-list from hep-ph)
Diffractive vector meson photo-production in oxygen-oxygen and neon-neon ultraperipheral collisions at energies available at the CERN Large Hadron Collider
J. Cepila🇨🇿 · J. G. Contreras🇨🇿 · M. Matas🇨🇿 · A. Ridzikova🇨🇿
The energy-dependent hotspot model is used to predict cross sections for vector-meson diffractive photo-nuclear production off oxygen ( $γ$ O) and neon ( $γ$ Ne) that can be extracted from ultra-peripheral O--O and Ne--Ne collisions, recently recorded at the LHC. In both cases, two models are used to describe the nuclear shapes. Woods-Saxon prescriptions for O and Ne as well as an alpha-cluster description of O and a bowling-pin-like shape for Ne, according to the PGCM formalism. Predictions are presented for the dependence on the centre-of-mass energy of the photon--nucleus system, as well as on Mandelstam- $t$ , of the cross sections for the coherent and the incoherent photo-nuclear production of $ρ^{0}$ and J/ $ψ$ vector mesons. Furthermore, the rapidity dependence of the ultra-peripheral cross section is reported for all cases. It is found that the incoherent process provides a measurable signature for the approach to the gluon-saturation regime, and that the simultaneous determination of $ρ^{0}$ and J/ $ψ$ coherent and incoherent production provides a strong constraint on nuclear models for both O and Ne.
Comments:
19 pages, 9 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2509.11359 [pdf]
PRC(2026)·2 citations
11
[Submitted on 14 Sept 2025] (cross-list from quant-ph)
Observation of quantum-field-theory dynamics on a spin-phonon quantum computer
Anton T. Than🇺🇸 · Saurabh V. Kadam🇺🇸 · Vinay Vikramaditya🇺🇸 · Nhung H. Nguyen🇺🇸 · Xingxin Liu🇺🇸 · Zohreh Davoudi🇺🇸 · Alaina M. Green🇺🇸 · Norbert M. Linke🇺🇸
Simulating out-of-equilibrium dynamics of quantum field theories in nature is challenging with classical methods, but is a promising application for quantum computers. Unfortunately, simulating interacting bosonic fields involves a high boson-to-qubit encoding overhead. Furthermore, when mapping to qubits, the infinite-dimensional Hilbert space of bosons is necessarily truncated, with truncation errors that grow with energy and time. A qubit-based quantum computer, augmented with an active bosonic register, and with qubit, bosonic, and mixed qubit-boson quantum gates, offers a more powerful platform for simulating bosonic theories. We demonstrate this capability experimentally in a hybrid analog-digital trapped-ion quantum computer, where qubits are encoded in the internal states of the ions, and the bosons in the ions' motional states. Specifically, we simulate nonequilibrium dynamics of a (1+1)-dimensional Yukawa model, a simplified model of interacting nucleons and pions, and measure fermion- and boson-occupation-state probabilities. These dynamics populate high bosonic-field excitations starting from an empty state, and the experimental results capture well such high-occupation states. This simulation approaches the regime where classical methods become challenging, bypasses the need for a large qubit overhead, and removes truncation errors. Our results, therefore, open the way to achieving demonstrable quantum advantage in qubit-boson quantum computing.
Comments:
14 pages, 6 figures
Subjects:
Quantum Physics (quant-ph); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2509.11477 [pdf]
12 citations
12
[Submitted on 15 Sept 2025] (cross-list from nucl-ex)
$A_{β} [E_{β}]$ in $^{37}$ K decay: new physics with opposite $β$ helicity
Melissa Anholm🇨🇦 · J.A. Behr🇨🇦 · D.G. Melconian🇺🇸 · G. Gwinner🇨🇦 · A. Gorelov🇨🇦 · J.C. McNeil🇨🇦 · B. Fenker🇺🇸 · S. Behling🇺🇸
By extending our analysis and simulations of our $^{37}$ K $β$ -decay data set to allow the $β$ asymmetry with respect to nuclear spin to vary with $β$ energy $E_{β}$ , we have gained sensitivity to new physics that depends on a helicity factor for the $β$ , $m_{β} / E_{β}$ . In particular, we constrain Lorentz scalar and tensor quark-lepton interaction strengths at a sensitivity complementary to the similar Fierz interference term in neutron $β$ decay. Our result for that new physics is a Fierz interference term $b$ = 0.033 $\pm$ 0.084 (stat) $\pm$ 0.039 (syst), consistent with the standard model electroweak interaction value $b = 0$ . We consider presently achieved complementarity to $β$ -decay and particle physics experiments, along with projectable technical improvements to our method.
Comments:
Observable now labelled b throughout, pedagogy including equations fixed. Included combined Abeta, b, fT constraint on revised exclusion plot more carefully
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2509.11502 [pdf]
PRC(2026)·0 citations
13
[Submitted on 15 Sept 2025] (cross-list from astro-ph.HE)
Investigating the correlations of bulk properties of hyperon star with dark matter
Rashmita Jena🇮🇳 · Padmalaya Dash🇮🇳 · S.K. Biswal🇮🇳
The strong gravitational pull of the neutron star leads to the accretion of dark matter (DM) inside the core of the neutron star. The accretion of DM affects the bulk properties of the neutron star. Here, we study how the accretion of WIMP (Weakly Interacting Massive Particles) dark matter particles affects the $Δ -$ admixed hyperon star's bulk properties specifically mass, radius, tidal deformability, $f -$ mode frequency and moment of inertia. The inclusion of dark matter softens the EOS (equation of state) and reduces the maximum possible mass, canonical radius, canonical tidal deformability, and moment of inertia of canonical star. However, the $f -$ mode frequency of the canonical star increases. We find a cubical correlation between the dark matter fermi momenta $k_{f}^{D M}$ and bulk properties of canonical star.
Comments:
28 pages, 8 Figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2509.11758 [pdf]
0 citations
14
[Submitted on 15 Sept 2025] (cross-list from physics.ed-ph)
Nuclear Beavers
Joshua Wylie · Pablo Giuliani · Kyle Godbey · Sylvester Agbemava
Nuclear physics is a very abstract field with little accessibility for wider audiences, and yet it is a field of physics with far reaching implications for everyday life. The Nuclear Beavers demonstration is a hands-on experience that offers an intuitive lens into nuclear structure and decay. We aim to provide a more accessible entry point for students and educators by substituting complex nuclear structures and interactions with tactile building blocks following well-defined rules, thereby opening nuclear physics concepts to the general public.
Comments:
10 pages, 4 figures in main. Supplemental material available with 9 pages and 5 figures. The following article has been submitted to/accepted by The Physics Teacher. After it is published, it will be found at https://doi.org/10.1119/5.0253360
Subjects:
physics.ed-ph (physics.ed-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2509.12055 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE