Nuclear Theory·nucl-th

Friday·January 3, 2025

23 papers—11 primary·12 cross-listed

01
Erratum: Exact solutions to the fermion propagator Schwinger-Dyson equation in Minkowski space with on-shell renormalization for quenched QED \newline [Phys. Rev. D 96, 036021 (2017)]
Shaoyang Jia · Michael R. Pennington
With the introduction of a spectral representation, the Schwinger--Dyson equation (SDE) for the fermion propagator is formulated in Minkowski space in QED. After imposing the on-shell renormalization conditions, numeric solutions for the fermion propagator spectral functions are obtained in four dimensions with a renormalizable version of the Gauge Technique Ansatz for the fermion-photon vertex in the quenched approximation in the Yennie gauge. Despite the limitations of this model, having an explicit solution provides a guiding example of the fermion propagator with the correct analytic structure.
nucl-thhep-ph0 citations
02
Bayesian analysis of hybrid neutron star EOS constraints within an instantaneous nonlocal chiral quark matter model
Alexander Ayriyan🇵🇱 · David Blaschke🇵🇱 · Juan Pablo Carlomagno🇦🇷 · Gustavo A. Contrera🇦🇷 · Ana Gabriela Grunfeld🇦🇷
We present a physics-informed Bayesian analysis of equation of state constraints using observational data for masses, radii and tidal deformability of pulsars and a generic class of hybrid neutron star equation of state with color superconducting quark matter on the basis of a recently developed nonlocal chiral quark model. The nuclear matter phase is described within a relativistic density functional model of the DD2 class and the phase transition is obtained by a Maxwell construction. We find the region in the two-dimensional parameter space spanned by the vector meson coupling and the scalar diquark coupling, where three conditions are fulfilled: (1) the Maxwell construction can be performed, \mbox{(2) the maximum} mass of the hybrid neutron star is not smaller than \mbox{2.0 M $_{⊙}$ } and (3) the onset density of the phase transition is not below the nuclear saturation density $n_{0} = 0.15$ fm $^{- 3}$ . The result of this study shows that the favorable neutron star equation of state has low onset masses for the occurrence of a color superconducting quark matter core between 0.5-0.7 $M_{⊙}$ and maximum masses in the range 2.15-2.22 $M_{⊙}$ . In the typical mass range of 1.2-2.0 $M_{⊙}$ , the radii of these stars are between 11.9 and 12.4 km, almost independent of the mass. In principle, hybrid stars would allow for larger maximum masses than provided by the hadronic reference equation of state.
nucl-thastro-ph.HEhep-phUniverse(2025)·20 citations
03
Systematic study of large-momentum distribution in nuclei with the operator product expansion
Jiexin Yu🇨🇳 · Bingwei Long🇨🇳
The operator product expansion (OPE) is applied in conjunction with Pionless effective field theory to study the short-rang structure of nuclei. By matching the OPE with the selected nuclear potentials for nucleon-nucleon scattering states, we obtain the Wilson coefficients. The nucleon momentum distribution in the deuteron is then used to test the OPE against the predictions of these nuclear potentials. In order to achieve a systematic separation of short-range and long-range interactions, we discuss how the OPE approximation can be improved by including higher-order EFT potentials and higher-dimension local operators.
nucl-thPRC(2025)·1 citation
04
Deep learning for exploring hadron-hadron interactions
Lingxiao Wang🇯🇵
In this proceeding, we introduce deep learning technologies for studying hadron-hadron interactions. To extract parameterized hadron interaction potentials from collision experiments, we employ a supervised learning approach using Femtoscopy data. The deep neural networks (DNNs) are trained to learn the inverse mapping from observations to potentials. To link between experiments and first-principles simulations, we further investigate hadronic interactions in Lattice QCD simulations from the HAL QCD method perspective. Using an unsupervised learning approach, we construct a model-free potential function with symmetric DNNs, aiming to learn hadron interactions directly from simulated correlation functions (equal-time Nambu-Bethe-Salpeter amplitudes). On both fronts, deep learning methods show great promise in advancing our understanding of hadron interactions.
nucl-thhep-latJ.Subatomic Part.Cosmol.(2025)·5 citations
05
Closed-form formulas in number-conserved pairing theory
G. J. Fu
In this work, I present closed-form formulas for the norm and many-body density matrices between general wave functions with exact particle numbers in pairing theory, using properties of the generalized Kronecker delta. These formulas, expressed as sums of minors and Pfaffians, apply to both even and odd particle-number systems and accommodate pair condensate as well as broken-pair configurations. This formalism directly facilitates applications in the generator coordinate method and symmetry restoration techniques, including angular momentum projection.
nucl-th1 citation
06
Reexamination of nuclear structure properties and shape coexistence of nuclei around A70
Jameel-Un Nabi · Tuncay Bayram · Mahmut Boyukata · Asim Ullah · Anes Hayder · Syeda Zainab Naqvi
We reexamine the nuclear structure properties of waiting point nuclei around A70 using the interacting boson model 1 (IBM 1) and the relativistic mean field (RMF) model. Effective density dependent meson exchange functional (DD ME2) and density dependent point coupling functional (DD PC1) were used for the RMF calculations. We calculated the energy levels, the geometric shapes, binding and separation energies of nucleons and quadrupole deformation parameters (\b{eta}2). The shape coexistence phenomena in A 70 nuclei (68Se, 70Se, 70Br, 70Kr, 72Kr, 74Kr, 74Rb, and 74Sr) was later investigated. Spherical and deformed shapes of the selected waiting point nuclei were computed using the IBM 1 and RMF models, respectively. The proton neutron quasiparticle random phase approximation (pn QRPA) model was used to calculate \b{eta} decay properties (Gamow Teller strength distributions, \b{eta} decay half lives, and branching ratios) of selected nuclei as a function of \b{eta}2. The results revealed a significant variation in calculated half lives and Gamow Teller strength distributions as the shape parameter was changed. The \b{eta}2 computed via DD ME2 functional resulted in half lives in best agreement with the measured data.
nucl-thastro-ph.SRNPA(2024)·0 citations
07
General features of the stellar matter equation of state from microscopic theory, new maximum-mass constraints, and causality
Francesca Sammarruca🇺🇸 · Tomiwa Ajagbonna🇺🇸
The profile of a neutron star probes a very large range of densities, from the density of iron up to several times the density of saturated nuclear matter, and thus no theory of hadrons can be considered reliable if extended to those regions. We emphasize the importance of taking contemporary ab initio theories of nuclear and neutron matter as the baseline for any extension method, which will unavoidably involve some degree of phenomenology. We discuss how microscopic theory, on the one end, with causality and maximum-mass constraints, on the other, set strong boundaries to the high-density equation of state. We present our latest neutron star predictions where we combine polytropic extensions and parametrizations guided by speed of sound considerations. The predictions we show include our baseline neutron star cooling curves.
nucl-thFront.Astron.Space Sci.(2025)·2 citations
08
Unexpected Rise in Nuclear Collectivity from Short-Range Physics
Kevin S. Becker · Kristina D. Launey · Andreas Ekström · Tomáš Dytrych · Daniel Langr · Grigor H. Sargsyan · Jerry P. Draayer
We discover a surprising relation between the collective motion of nucleons within atomic nuclei, traditionally understood to be driven by long-range correlations, and short-range nucleon-nucleon interactions. Specifically, we find that quadrupole collectivity in low-lying states of $^{6}$ Li and $^{12}$ C, calculated with state-of-the-art ab initio techniques, is significantly influenced by two opposing $S$ -wave contact couplings that subtly alter the surface oscillations of one largely deformed nuclear shape, without changing that shape's overall contribution within the nucleus. The results offer new insights into the nature of emergent nuclear collectivity and its link to the underlying nucleon-nucleon interaction at short distances.
nucl-thPRL(2026)·8 citations
09
Isospin effect on the liquid-gas phase transition for finite nuclei
S. Mallik
The phenomenon of nuclear liquid-gas phase transition is a topic of contemporary interest. In heavy-ion collisions, there is no direct way of accessing the thermodynamic variables like pressure, density, free energy, entropy etc., and unambiguous detection of phase transition becomes difficult. A peak in the first order derivative of total multiplicity with respect to temperature (commonly abbreviated as the multiplicity derivative) has been established as a new experimentally accessible signature of the nuclear liquid-gas phase transition. In this work, the effect of isospin asymmetry in the fragmenting system, as well as the nuclear equation of state, on the multiplicity derivative and specific heat at constant volume is investigated within the framework of the Canonical Thermodynamical Model (CTM) with a semi-microscopic cluster functional.
nucl-thhep-phnucl-exNPA(2025)·3 citations
10
White Paper on Software Infrastructure for Advanced Nuclear Physics Computing
P. M. Jacobs🇺🇸 · A. Boehnlein🇺🇸 · B. Sawatzky🇺🇸 · J. Carlson🇺🇸 · I. Cloet🇺🇸 · M. Diefenthaler🇺🇸 · R. G. Edwards🇺🇸 · K. Godbey🇺🇸 · W. R. Hix🇺🇸 · K. Orginos🇺🇸 · T. Papenbrock🇺🇸 · M. Ploskon🇺🇸 and 40 other authors
This White Paper documents the discussion and consensus conclusions of the workshop "Software Infrastructure for Advanced Nuclear Physics Computing" (SANPC 24), which was held at Jefferson Lab on June 20-22, 2024. The workshop brought together members of the US Nuclear Physics community with data scientists and funding agency representatives, to discuss the challenges and opportunities in advanced computing for Nuclear Physics in the coming decade. Opportunities for sustainable support and growth are identified, within the context of existing and currently planned DOE and NSF programs.
nucl-thhep-phnucl-ex3 citations
11
Validation and extrapolation of atomic mass with physics-informed fully connected neural network
Yiming Huang · Jinhui Chen · Jiangyong Jia · Lu-Meng Liu · Yu-Gang Ma · Chunjian Zhang
Machine learning offers a powerful framework for validating and predicting atomic mass. We compare three improved neural network methods for representation and extrapolation for atomic mass prediction. The powerful method, adopting a macroscopic-microscopic approach and treating complex nuclear effects as output labels, achieves superior accuracy in AME2020, yielding a much lower root-mean-square deviation of 0.122 MeV in the test set, significantly lower than alternative methods. It also exhibits a better extrapolation performance when predicting AME2020 from AME2016, with a root-mean-square deviation of 0.191 MeV. We further conduct sensitivity analyses against the model inputs to verify interpretable alignment beyond statistical metrics. Incorporating theoretical predictions of magic numbers and masses, our fully connected neural networks reproduce key nuclear phenomena including nucleon pairing correlation and magic number effects. The extrapolation capability of the framework is discussed and the accuracy of predicting new mass measurements for isotope chains has also been tested.
nucl-thnucl-exPRC(2025)·14 citations
12
Twist-3 contributions to wide-angle photoproduction of pions
P. Kroll🇩🇪 · K. Passek-Kumericki🇭🇷
We investigate wide-angle pi^0 photoproduction within the handbag approach to twist-3 accuracy. In contrast to earlier work both the 2-particle as well as the 3-particle twist-3 contributions are taken into account. It is shown that both are needed for consistent results that respect gauge invariance and crossing properties. The numerical studies reveal the dominance of the twist-3 contribution. With it fair agreement with the recent CLAS measurement of the pi^0 cross section is obtained. We briefly comment also on wide-angle photoproduction of other pseudoscalar mesons.
↳ hep-phnucl-thPRD(2018)·20 citations
13
On the Wiedemann-Franz law violation in Graphene and quark-gluon plasma systems
Ashutosh Dwibedi🇮🇳 · Subhalaxmi Nayak🇮🇳 · Sathe Subodh Kiran🇮🇳 · Sabyasachi Ghosh🇮🇳 · Sesha Vempati🇮🇳
A comparative study of the thermodynamic and transport properties of the ultra-relativistic quark-gluon plasma produced in heavy ion collisions with the "quasi-relativistic" massless electron-hole plasma in graphene sample has been performed. We observe that the enthalpy per net charge carriers emerges as a useful physical quantity determining the transport variables in hydrodynamic domain. Lorenz ratio is defined as thermal to electrical conductivity ratio, normalized by temperature and Lorenz number $L_{0} = \frac{π ^{2}}{3} (\frac{k _{B}}{e})^{2}$ . The validity of the Wiedemann-Franz law can be checked by evaluating the Lorenz ratio, which is expected to be unity. We investigate the validity of the Wiedemann-Franz law by examining whether the Lorenz ratio equals unity or deviates from it. Our findings indicate that, within the fluid-based framework, the Lorenz ratio consistently leads to a violation of the Wiedemann-Franz law. This is attributed to the proportional relation between Lorenz ratio and enthalpy per net charge carriers in the fluid. Based on the experimental observation, graphene and quark-gluon plasma, both systems at a low net carrier density, violate the Wiedemann-Franz law due to their fluidic nature. However, graphene at a relatively high net carrier density obeys the Wiedemann-Franz law, followed by metals with high Fermi energy or electron density. It indicates a fluid to the non-fluid transition of the graphene system from low to high carrier density. In this regard, the fluid or non-fluid aspect of quark-gluon plasma at high density is yet to be explored by future facilities like Compressed Baryonic Matter and Nuclotron-based Ion Collider fAcility experiments.
↳ cond-mat.str-elcond-mat.stat-mechnucl-thEur.Phys.J.B(2025)·3 citations
14
Tricritical behavior of a relativistic field theory in one dimension
Heron Caldas🇧🇷 · A. L. Mota🇧🇷
The tricritical behavior in a class of one-dimensional (1D) field theories that exhibit spontaneous symmetry breaking at zero temperature and chemical potential is analyzed. In the Gross-Neveu (GN)-type models of massless fermions the discrete chiral symmetry is spontaneously broken. After doping, the symmetry is restored at a critical chemical potential. We investigate the temperature effects on this doped 1D system under an external constant Zeeman magnetic field $B_{0}$ . We find that $B_{0}$ suppresses the gapless behavior present for certain values of chemical potential and is able to induce a gapless-gapped phase transition at a critical field strength. We also discuss about the consequences of the consideration of inhomogeneous condensates to the tricritical point, within the Ginzburg-Landau expansion.
↳ hep-thcond-mat.str-elhep-phnucl-thJ.Stat.Mech.(2025)·0 citations
15
Uncertainties in tellurium-based dark matter searches stemming from nuclear structure uncertainties
Daniel J. Heimsoth🇺🇸 · Rebecca Kowalski🇺🇸 · Danielle H. Speller🇺🇸 · Calvin W. Johnson🇺🇸 · A. Baha Balantekin🇺🇸 · Susan N. Coppersmith🇦🇺
Using tellurium dioxide as a target, we calculate uncertainties on 90% upper confidence limits of Galilean effective field theory (Galilean EFT) couplings to a weakly-interacting massive particle (WIMP) dark matter candidate due to uncertainties in nuclear shell models. We find that these uncertainties in naturally-occurring tellurium isotopes are comparable across the different Galilean EFT couplings to uncertainties in xenon, with some reaching over 100%. We also consider the effect these nuclear uncertainties have on estimates of the annual modulation of dark matter from these searches, finding that the uncertainties in the modulation amplitude are proportional to the non-modulating upper confidence limit uncertainties. We also show that the determination of the modulation phase is insensitive to changes in the nuclear model for a given isotope.
↳ hep-phastro-ph.COhep-exnucl-thPRD(2025)·0 citations
16
Strangeness in the proton from W+charm production and SIDIS data
Trey Anderson🇺🇸 · W. Melnitchouk🇺🇸 · N. Sato🇺🇸
We perform a global QCD analysis of unpolarized parton distribution functions (PDFs) in the proton, including new $W +$ \,charm production data from $pp$ collisions at the LHC and semi-inclusive pion and kaon production data in lepton-nucleon deep-inelastic scattering, both of which have been suggested for constraining the strange quark PDF. Compared with a baseline global fit that does not include these datasets, the new analysis reduces the uncertainty on the strange quark distribution over the range $0.01 < x < 0.3$ , and provides a consistent description of processes sensitive to strangeness in the proton. Including the new datasets, the ratio of strange to nonstrange sea quark distributions is $R_{s} = (s + s ˉ) / (u ˉ + d ˉ) = {0.7 2_{- 0.34}^{+ 0.52}, 0.4 6_{- 0.20}^{+ 0.30}, 0.3 2_{- 0.15}^{+ 0.23}}$ for $x = {0.01, 0.04, 0.1}$ at $Q^{2} = 4$ ~GeV $^{2}$ . The data place more stringent constraints on the strange asymmetry $s - s ˉ$ , which is found to be consistent with zero in this range.
↳ hep-phhep-exnucl-thPRD(2025)·14 citations
17
Collins-Soper Kernel in the QCD Instanton Vacuum
Wei-Yang Liu🇺🇸 · Ismail Zahed🇺🇸 · Yong Zhao🇺🇸
We outline a general framework for evaluating the non-perturbative soft functions in the QCD instanton vacuum. In particular, from the soft function we derive the Collins-Soper (CS) kernel, which drives the rapidity evolution of the transverse-momentum-dependent parton distributions. The resulting CS kernel, when supplemented with the perturbative contribution, agrees well with recent lattice results and some phenomenological parameterizations. Moreover, our CS kernel depends logarithmically on the large quark transverse separation, providing a key constraint on its phenomenological parametrization. Finally, a lattice calculation can be directly compared to our generic results in Euclidean signature, thus providing a new approach for evaluating the soft function and extracting the CS kernel by analytical continuation.
↳ hep-phhep-lathep-thnucl-thPRD(2025)·10 citations
18
Exploring QGP-like phenomena with Charmonia in $p + p$ collisions at $s = 13$ TeV
Captain R. Singh🇮🇳 · Partha Bagchi🇮🇳 · Raghunath Sahoo🇮🇳 · Jan-e Alam🇮🇳
In ultrarelativistic collisions of nuclei at the Large Hadron Collider, the created QCD environment rapidly changes, leading to a non-adiabatic evolution of the quantum states involved. Considering this, we first examine the pre-equilibrium state of QCD matter and its effect on the initially produced charmonium using a temperature-independent Hamiltonian. As the QCD matter reaches local thermal equilibrium, this Hamiltonian transforms to its finite temperature counterpart. To model the pre-equilibrium stage, we use the bottom-up thermalization approach to determine the effective temperature of the QCD matter, followed by a Gubser-type expansion for the thermalized medium. Additionally, we consider collisional damping, gluonic dissociation, and regeneration mechanisms, which specifically modify the charmonium yield in the thermalized medium. Mainly, the gluonic dissociation and collisional damping cause a reduction in the yield conversely, regeneration through gluonic deexcitation enhances the yield of charmonium. Further, we explore the combined effects of these mechanisms on the collective yield of charmonium states with transverse momentum ( $p_{T}$ ) and event multiplicity in the proton-proton collisions at $s = 13$ TeV. Based on our findings, we contend that the combined effects of these mechanisms can serve as a robust probe for determining the possible existence of a thermalized QCD medium in such a small collision system.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·3 citations
19
First-order phase transition in dynamical 3-flavor QCD at imaginary isospin
Gergely Endrodi🇭🇺 · Guy D. Moore🇩🇪 · Alessandro Sciarra🇩🇪
We revisit QCD with three mass-degenerate quark flavors at an imaginary isospin chemical potential set to 4 pi T/3. This choice corresponds to a special point in the parameter space, where the theory possesses an exact Z(3) center symmetry. Through a finite-size scaling analysis, we demonstrate that in this case the finite temperature QCD transition is of first order and entails singular behavior both in the Polyakov loop and in the quark condensate. Our results are based on simulations with stout-smeared staggered quarks and a dedicated multi-histogram analysis.
↳ hep-lathep-phnucl-thPoS(2025)·4 citations
20
Stellar Weak Rates and Mass Fractions of 20 Most Important $f p$ -shell Nuclei with $A < 65$
Asim Ullah · Jameel-Un Nabi
This work presents stellar weak rates and mass fractions of 20 most important electron capture (ec) and beta decay (bd) nuclei with $A < 65$ according to a recent study during the presupernova evolution of massive stars. The mass fractions of these nuclei were calculated using the Sahas equation which assumes nuclear statistical equilibrium for a set of initial conditions ( $T_{9}$ , $ρ$ and $Y_{e}$ ) that represents the trajectory which a massive stars central region takes after its silicon core burns. Our computed mass fractions were found in decent comparison in most cases, and up to a factor 4 difference was noted when compared with the Independent Particle Model results. The weak interaction (ec and bd) rates were calculated in a totally microscopic fashion using the proton neutron quasiparticle random phase ap proximation model and without assuming the Brink Axel hypothesis. The rates were computed for a wide range of density ( $10$ - $1 0^{11}$ ) g/cm $^{3}$ and temperature (0.01-30) GK. In comparison with large scale shell model, our computed rates were found bigger at high values of core temperature. The current study may contribute in a more realistic simu lation of stellar evolution processes and modeling of core collapse supernovae.
↳ astro-ph.SRnucl-thBraz.J.Phys.(2022)·1 citation
21
Gluon mass scale through the Schwinger mechanism
M. N. Ferreira🇨🇳 · J. Papavassiliou🇪🇸
It has long been argued that the action of the Schwinger mechanism in the gauge sector of Quantum Chromodynamics leads to the generation of a gluon mass scale. Within this scenario, the analytic structure of the fundamental vertices is modified by the creation of scalar colored excitations with vanishing mass. In the limit of zero momentum transfer, these terms act as massless poles, providing the required conditions for the infrared stabilization of the gluon propagator, and producing a characteristic displacement to the associated Ward identities. In this article we offer an extensive overview of the salient notions and techniques underlying this dynamical picture. We place particular emphasis on recent developments related to the exact renormalization of the mass, the nonlinear nature of the pole equation, and the key role played by the Fredholm alternative theorem.
↳ hep-phhep-lathep-thnucl-thPPNP(2025)·23 citations
22
Measurement of $^{6} H$ ground state energy in an electron scattering experiment at MAMI-A1
Tianhao Shao · Jinhui Chen · Josef Pochodzalla · Patrick Achenbach · Mirco Christmann · Michael O. Distler · Luca Doria · Anselm Esser · Julian Geratz · Christian Helmel · Matthias Hoek · Ryoko Kino and 19 other authors
For the first time the neutron-rich hydrogen isotope $^{6} H$ was produced in an electron scattering experiment in the reaction $^{7} Li (e, e^{'} p π^{+})^{6} H$ using the spectrometer facility of the A1 Collaboration at the Mainz Microtron accelerator. By measuring the triple coincidence between the scattered electron, the produced proton, and $π^{+}$ , the missing mass spectrum of $^{6} H$ was obtained. A clear peak above $^{3}$ H+n+n+n energy threshold was seen resulting in a ground state energy of $^{6} H$ at $2.3 \pm 0.5 (stat.) \pm 0.4 (syst.)$ MeV with a width of $1.9 \pm 1.0 (stat.) \pm 0.4 (syst.)$ MeV. This work challenges the understandings of multi-nucleon interactions and presents a new method to study light neutron-rich nuclei with electron scattering experiments.
↳ nucl-exnucl-thPRL(2025)·9 citations
23
Impact of QCD sum rules coupling constants on neutron stars structure
F. Moradi Jangal🇮🇷 · H. R. Moshfegh🇮🇷 · K. Azizi🇮🇷
We present a detailed investigation on the structure of neutron stars, incorporating the presence of hyperons within a relativistic model under the mean-field approximation. Employing coupling constants derived from QCD sum rules, we explore the particle fraction in beta equilibrium and establish the mass-radius relationship for neutron stars with hyperonic matter. Additionally, we compute the stellar Love number ( $K_{2}$ ) and the tidal deformability parameter ( $Λ$ ), providing valuable insights into the dynamical properties of these celestial objects. Through comparison with theoretical predictions and observational data, our results exhibit good agreement, affirming the validity of our approach. These findings contribute significantly to refining the understanding of neutron star physics, particularly in environments containing hyperons, and offer essential constraints on the equation of state governing such extreme astrophysical conditions.
↳ hep-phastro-ph.HEnucl-thEPJC(2025)·5 citations

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