Nuclear Theory·nucl-th

Tuesday·June 17, 2025

24 papers—10 primary·14 cross-listed

11
Asymmetric muon-antimuon emission from $Z^{0}$ decays: a clear magnetometer in relativistic heavy-ion collisions
Alejandro Ayala🇲🇽 · Ana Julia Mizher🇧🇷 · Javier Rendón🇲🇽
We show that a very clear signal of the presence of a strong magnetic field during the early stage of a high-energy heavy-ion collision is provided by the decay of the $Z^{0}$ into dimuon pairs. We find that the process is highly anisotropic, producing pairs mainly out of plane, as signaled by a negative value of $v_{2}$ , and leads to an antimuon transverse momentum distribution which peaks at a higher value of the transverse momentum compared to the peak of the muon transverse momentum distribution. We also show that the process does not produce a significant distortion of the $Z^{0}$ spectral function. The signal can be identified by comparing the dimuon-invariant mass and the individual muon and antimuon spectra produced in semicentral heavy-ion collisions with the corresponding scaled spectra produced in p+p collisions at the $Z^{0}$ peak.
↳ hep-phhep-exnucl-exnucl-thPRC(2026)·3 citations
12
Charge Pickup Reaction Cross Section for Neutron-Rich p-Shell Isotopes at 900A MeV
J.-C. Zhang · B.-H. Sun · I. Tanihata · S. Terashima · F. Wang · R. Kanungo · C. Scheidenberger · F. Ameil · J. Atkinson · Y. Ayyad · S. Bagchi · D. Cortina-Gil and 25 other authors
We report charge pickup reaction cross sections for 24 \textit{p}-shell isotopes, including $^{8, 9}$ Li, $^{10 - 12}$ Be, $^{10, 13 - 15}$ B, $^{12, 14 - 19}$ C and $^{14, 15, 17 - 22}$ N, measured at relativistic energies (approximately 900 $A$ MeV) on both hydrogen and carbon targets. For the first time, we reveal a universal rapid increase in the charge pickup cross sections of unstable projectiles with isospin asymmetry along several isotopic chains. The cross sections can be decoupled into distinct contributions from the mass number and isospin asymmetry of the projectile, highlighting the critical role of the latter, and can be formulated empirically.
↳ nucl-exnucl-thPRX(2025)·4 citations
13
Properties and microscopic structures of dense stellar matter in RMF models
Jia-Xing Niu🇨🇳 · Hao Sun🇨🇳 · Cheng-Jun Xia🇨🇳 · Toshiki Maruyama🇯🇵
Data tables on the equation of state (EOS) and microscopic structures for cold dense stellar matter with proton fractions $Y_{p} = 0.01$ - $0.65$ and baryon number densities $n_{b} = 1 0^{- 8}$ - $2 fm^{- 3}$ are obtained adopting 13 different relativistic density functionals, i.e., NL3, PK1, PK1r, GM1, MTVTC, DD-LZ1, PKDD, DD-ME2, TW99, DD-MEX, DD-MEX1, DD-MEX2, and DD-MEY. The EOSs of dense stellar matter inside neutron stars with baryon number densities $n_{b} = 7.6 \times 1 0^{- 11}$ - $2 fm^{- 3}$ are obtained as well fulfilling $β$ -stability condition. In general, the dense stellar matter exhibits droplet phase at $n_{b} ≲ 0.015 fm^{- 3}$ , while more exotic structures such as rods, slabs, tubes, and bubbles appear sequentially as density increases. The critical proton fractions $Y_{p}^{drip}$ ( $\approx 0.26$ -0.31) for neutron drip are obtained, where neutron gas emerges outside of nuclei at $Y_{p} < Y_{p}^{drip}$ . For dense stellar matter at small densities ( $n_{b} ≲ 1 0^{- 5} fm^{- 3}$ ) or large proton fractions ( $n_{b} ≲ 0.1 fm^{- 3}$ and $Y_{p} ≳ Y_{p}^{drip}$ ), the EOSs and microscopic structures are generally insensitive to the adopted density functionals. With the onset of neutron drip at $Y_{p} ≲ Y_{p}^{drip}$ , the uncertainties emerge and peak at $n_{b} \approx 0.02 fm^{- 3}$ within the range $1 0^{- 5} ≲ n_{b} ≲ 0.1 fm^{- 3}$ . At $n_{b} ≳ 0.1 fm^{- 3}$ , the dense stellar matter becomes uniform and muons eventually appear, where the uncertainties in the EOSs grow significantly.
↳ astro-ph.HEnucl-thPRC(2026)·5 citations
14
The QUEST Database of Highly-Accurate Excitation Energies
Pierre-François Loos · Martial Boggio-Pasqua · Aymeric Blondel · Filippo Lipparini · Denis Jacquemin
We report theoretical best estimates of vertical transition energies (VTEs) for a large number of excited states and molecules: the \textsc{quest} database. This database includes 1489 \emph{aug}-cc-pVTZ VTEs (731 singlets, 233 doublets, 461 triplets, and 64 quartets) for both valence and Rydberg transitions occurring in molecules containing from 1 to 16 non-hydrogen atoms. \textsc{Quest} also includes a significant list of VTEs for states characterized by a partial or genuine double-excitation character, known to be particularly challenging for many computational methods. The vast majority of the reported values are deemed chemically-accurate, that is, are within $\pm 0.05$ eV of the FCI/\emph{aug}-cc-pVTZ estimate. This allows for a balanced assessment of the performance of popular excited-state methodologies. We report the results of such benchmarks for various single- and multi-reference wavefunction approaches, and provide extensive supporting information allowing testing of other models. All corresponding data associated with the \textsc{quest} database, along with analysis tools, can be found in the associated \textsc{GitHub} repository at the following URL: https://github.com/pfloos/QUESTDB.
↳ physics.chem-phcond-mat.mtrl-scicond-mat.str-elnucl-th+1J.Chem.Theor.Comput.(2025)·4 citations
15
Recent Results on the Tetraneutron
Thomas Faestermann · Roman Gernhäuser
We describe the recent experiments which claimed an observation of a tetra-neutron signal. Production reactions like transfer, knockout, fragmentation or photodisintegration have been used at very different experiments and facilities to form systems just made of neutrons. As a possible explanation of the partly contradicting results we suggest that some observed the bound ground state and some an unbound but still correlated state of the four neutrons at different exitation energy. We also refer to some of the theoretical works.
↳ nucl-exnucl-th3 citations
16
Gapless neutron superfluidity in the crust of the accreting neutron stars KS 1731-260 and MXB 1659-29
Valentin Allard · Nicolas Chamel
The interpretation of the thermal evolution of the transiently accreting neutron stars MXB 1659-29 and KS 1731-260 after an outburst is challenging, both within the traditional deep-crustal heating paradigm and the thermodynamically consistent approach of Gusakov and Chugunov that accounts for neutron diffusion throughout the crust. All these studies assume that the neutron superfluid in the crust is at rest. However, we have recently shown that a finite superflow could exist and could lead to a new gapless superfluid phase if quantized vortices are pinned. We have revisited the cooling of MXB 1659-29 and KS 1731-260 and we have found that gapless superfluidity could naturally explain their late time cooling. We pursue here our investigation by performing new simulations of the thermal relaxation of the crust of MXB 1659-29 and KS 1731-260 within a Markov Chain Monte Carlo method accounting for neutron diffusion and allowing for gapless superfluidity. We have varied the global structure of the neutron star, the composition of the heat-blanketing envelope, and the mass accretion rate. In all cases, observations are best fitted by models with gapless superfluidity. Finally, we make predictions that could be tested by future observations.
↳ astro-ph.HEcond-mat.supr-connucl-thEPJA(2024)·6 citations
17
Temperature Dependence of Heavy Quark Diffusion from (2+1)-flavor Lattice QCD
Dennis Bollweg🇺🇸 · Jorge Luis Dasilva Golán🇺🇸 · Olaf Kaczmarek🇩🇪 · Rasmus Norman Larsen🇩🇪 · Guy D. Moore🇩🇪 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Hai-Tao Shu🇨🇳 · Simon Stendebach🇩🇪 · Johannes Heinrich Weber🇩🇪
We present a lattice determination of the heavy-quark diffusion coefficient in (2+1)-flavor QCD with almost physical quark masses. The momentum and spatial diffusion coefficients are extracted for a wide temperature range, from $T = 163$ MeV to $10$ GeV. The results are in agreement with previous works from the HotQCD collaboration, and show fast thermalization of the heavy quark inside the QGP. Near the chiral crossover temperature $T_{c} ≃ 150$ MeV, our results are close to the AdS/CFT estimation computed at strong coupling.
↳ hep-lathep-thnucl-thJHEP(2025)·23 citations
18
A Generalized False Vacuum Skyrme model
L. A. Ferreira🇧🇷 · L. R. Livramento🇧🇷
We propose a generalization of the False Vacuum Skyrme model for any simple compact Lie groups $G$ that leads to Hermitian symmetric spaces. The Skyrme field that in the original theory takes its values in $S U (2)$ Lie group, now takes its values in $G$ , while the remaining fields correspond to the entries of a symmetric, positive, and invertible $dim G \times dim G$ -dimensional matrix $h$ . This model is also an extension of the generalized BPS Skyrme model. We prove that the global minima correspond to the $h$ fields being self-dual solutions of the generalized BPS Skyrme model, together with a particular field configuration for the Skyrme field that leads to a spherically symmetric topological charge density. As in the case of the original model, the minimization of the energy leads to the so-called reduced problem, defined in the context of false vacuum decay. This imposes a condition on the Skyrme field, which, if satisfied, makes the total energy of the global minima, as well as the main properties of the model, equivalent to those obtained for the $G = S U (2)$ case. We study this condition and its consequences within the generalized rational map ansatz and show how it can be satisfied for $G = S U (p + q)$ , where $p$ and $q$ are positive integers, with the Hermitian symmetric spaces being $S U (p + q) / S U (p) \otimes S U (q) \otimes U (1)$ . In such a case, the model is completely equivalent to the $G = S U (2)$ False Vacuum Skyrme model, independent of the values of $p$ and $q$ . We also provide a numerical study of the baryon density, RMS radius, and binding energy per nucleon, which deepens the previous analysis conducted for the $S U (2)$ False Vacuum Skyrme model. Additionaly, in the case of $G = S U (3)$ , we have studied the application of our model to the description of the binding energies and masses of the $Λ$ -hypernuclei.
↳ hep-thmath-phmath.MPnlin.SI+1J.Phys.G(2026)·1 citation
19
Exact Renormalization Relation and Binding Energies for Three Identical Bosons
Langxuan Chen · Pengfei Zhang
In the low-energy limit, non-relativistic particles with short-range interactions exhibit universal behavior that is largely independent of microscopic details. This universality is typically described by effective field theory, in which the two-body interaction is renormalized to a single parameter-the scattering length. For systems of identical bosons, the three-body problem reveals the Efimov effect, a novel phenomenon proposed that necessitates the introduction of an additional three-body parameter. However, the exact relation between this three-body parameter, the coupling constants in the effective field theory, and the binding energies of Efimov states remains unresolved. In this Letter, we address this question through a comprehensive analysis of the Skorniakov-Ter-Martirosian equation with a finite cutoff. We establish an exact renormalization relation for the three-body parameter and determine its connection to the energies of Efimov bound states. These results are validated through high-precision numerical simulations. We expect our findings to be of fundamental interest across various fields, including atomic, nuclear, condensed matter, and particle physics, and to have broad applications in both few-body and many-body physics.
↳ cond-mat.quant-gasnucl-thPRA(2025)·3 citations
20
Studying Maximal Entanglement and Bell Nonlocality at an Electron-Ion Collider
Wei Qi🇨🇳 · Zijing Guo🇨🇳 · Bo-Wen Xiao🇨🇳
In this paper, we propose to test quantum entanglement and Bell nonlocality at an Electron-Ion Collider (EIC). By computing the spin correlations in quark-antiquark pairs produced via photon-gluon fusion, we find that longitudinally polarized photons produce maximal entanglement at leading order, while transversely polarized photons generate significant entanglement near the threshold and in the ultra-relativistic regime. Compared to hadron colliders, the EIC provides a cleaner experimental environment for measuring entanglement through the $γ^{*} g \to q q ˉ$ channel, offering a strong signal and a promising avenue to verify Bell nonlocality. This study extends entanglement measurements to the EIC, presenting new opportunities to explore the interplay of quantum information phenomena and hadronic physics in the EIC era.
↳ hep-phhep-exnucl-exnucl-th+1PRD(2026)·32 citations
21
Connecting dilaton thermal fluctuation with the Polyakov loop at finite temperature
Bing-Kai Sheng🇨🇳 · Yong-Liang Ma🇨🇳
Understanding the character of the deconfinement phase transition is one of the fundamental challenges in particle physics. In this work, we derive a formula for the expectation value of the Polyakov loop -- the order parameter of the deconfinement phase transition -- in pure $SU (N_{c})$ gauge systems at finite temperatures starting from the Coleman\textendash Weinberg-type effective potential encoding the trace anomaly of QCD. Our results are in good agreement with the Lattice QCD data and can effectively describe the large- $N_{c}$ behaviors of the expectation value of the Polyakov loop. Notably, our findings predict the strongest first-order deconfinement phase transition as $N_{c} \to + \infty$ . Furthermore, to establish a relation between the dilaton field and the Polyakov loop, we also derive the scale transformation rule for temperature based on quantum statistical mechanics. The results of this work may shed a light on the connection between deconfinement phase transition and evolution of scale symmetry in the thermal system.
↳ hep-phhep-latnucl-thJHEP(2026)·2 citations
22
Joint analysis of reactor and accelerator CE $ν$ NS data on germanium: implications for the Standard Model and nuclear physics
M. Atzori Corona🇮🇹 · M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · G. Co'🇮🇹 · F. Dordei🇮🇹 · C. Giunti🇮🇹
This work presents the first comprehensive joint analysis of all available Coherent Elastic Neutrino-Nucleus Scattering (CE $ν$ NS) data on germanium: those observed at the Spallation Neutron Source (SNS) by the COHERENT collaboration and those of the nuclear reactors revealed by the CONUS+ experiment using germanium detectors. In addition to COHERENT and CONUS+, we incorporate reactor data from TEXONO and $ν$ GeN, thereby enhancing both the statistical significance and the systematic reliability of our study. We provide state-of-the-art determinations of key nuclear physics and Standard Model parameters, including the neutron root-mean-square (rms) radius of germanium nuclei, the weak mixing angle, and the neutrino charge radius. The observed tension of about $2 σ$ between the COHERENT germanium measurement and the Standard Model prediction motivates a detailed reassessment of the theoretical cross-section. In particular, we examine the impact of nuclear form factors and uncertainties in the nuclear radius, as well as the potential influence of a systematic shift in the neutrino flux normalisation at the SNS. Our results highlight the reliability of CE $ν$ NS as a precision tool, reinforced by the complementarity of different experimental inputs, and lay the groundwork for future advances in the field.
↳ hep-phhep-exnucl-thPLB(2025)·13 citations
23
Global QCD analysis of spin PDFs in the proton with high- $x$ and lattice constraints
C. Cocuzza🇺🇸 · N. T. Hunt-Smith🇦🇺 · W. Melnitchouk🇺🇸 · N. Sato🇺🇸 · A. W. Thomas🇦🇺
We perform a comprehensive global QCD analysis of spin-dependent parton distribution functions (PDFs), combining all available data on inclusive and semi-inclusive deep-inelastic scattering (DIS), as well as inclusive weak boson and jet production in polarized $pp$ collisions, simultaneously extracting spin-averaged PDFs and fragmentation functions. Including recent Jefferson Lab DIS data at high $x$ , together with subleading power corrections to the leading twist framework, allows us to verify the stability of the PDFs for $W^{2} \geq 4$ GeV $^{2}$ and quantify the uncertainties on the spin structure functions more reliably. We explore the use of new lattice QCD data on gluonic pseudo Ioffe-time distributions, which, together with jet production and high- $x$ DIS data, improve the constraints on the polarized gluon PDF. The expanded kinematic reach afforded by the data into the high- $x$ region allows us to refine the bounds on higher twist contributions to the spin structure functions, and test the validity of the Bjorken sum rule.
↳ hep-phhep-latnucl-thPRD(2025)·22 citations
24
Bayesian Quantification of Observability and Equation of State of Twin Stars
Xavier Grundler🇺🇸 · Bao-An Li🇺🇸
The possibility of discovering twin stars, two neutron stars (NSs) with the same mass but different radii, is usually studied in forward modelings by using a restricted number of NS matter equation of state (EOS) encapsulating a first-order phase transition from hadronic to quark matter (QM). Informing our likelihood function with the NS radius data from GW170817 and using a meta-model with 9-parameters capable of mimicking most NS EOSs available in the literature, we conduct a Bayesian quantification of the observability and underlying EOSs of twin stars. Of the accepted EOSs, between 12-18\% yield twin stars, depending on the restrictions we place on the second branch. The possibility of twin stars remains robust even under recent observational constraints. We show that many of these twin star scenarios are observable with currently available levels of accuracy in measuring NS radii. We also present the marginalized posterior probability density functions (PDFs) of every EOS parameter for each of four mass-radius correlation topologies. We find that the inferred EOS depends sensitively on not only whether twin stars are present, but also the category of twin stars, indicating that the observation of twin stars would provide a strong constraint on the underlying EOS. In particular, for two coexisting hybrid stars having QM cores at different densities, the PDF for QM speed of sound squared $c_{qm}^{2}$ has two peaks, one below and another above the conformal limit $c_{qm}^{2} = 1/3$ predicted by perturbative QCD.
↳ astro-ph.HEastro-ph.GAastro-ph.SRnucl-ex+1PRD(2025)·18 citations

Affiliations

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