Nuclear Theory·nucl-th

Friday·February 28, 2025

14 papers—8 primary·6 cross-listed

01
Sensitivity of neutron drip lines and neutron star properties to the symmetry energy
Yeunhwan Lim🇰🇷 · Jeremy W. Holt🇺🇸
We investigate the influence of the nuclear symmetry energy and its density slope parameter on the neutron dripline and neutron star properties using a semi-classical liquid drop model (LDM) and energy density functionals constrained by chiral effective field theory. To analyze finite nuclei and mass tables, the nuclear symmetry energy at saturation density is fixed, and the surface tension is determined to minimize the root-mean-square deviation of the total binding energy for 2208 nuclei. Correlations between symmetry energy parameters and neutron driplines, crust-core transition densities, and the radii of $1.4 \msun$ neutron stars are explored using the LDM framework. Additionally, we examine the relationship between macroscopic properties, such as neutron star radii ( $R_{1.4}$ ), and microscopic properties, including the number of isotopes and the last bound nucleus for $Z = 28$ , within the LDM context.
nucl-thnucl-exPRC(2026)·6 citations
02
Beta decay and electron capture rates on manganese isotopes in astrophysical environments
R. Shehzadi · J.-U. Nabi · F. Farooq
The isotopes of manganese in the mass range A equal to 53 to 63 are abundant in the core material of high mass stars and are believed to be of prime importance in the progression of the pre collapse phases. During these late evolutionary phases, nuclear processes associated with weak interactions, including decay and electron capture (EC) on these isotopes, significantly alter the Ye (lepton to baryon ratio) of the cores composition. The temporal change of this parameter is one of the basic elements to simulate a successful explosion. Hence, the decay and EC rates of manganese (Mn) nuclides may serve as an important input in the simulation codes of core collapse supernova. In this paper, we focus on the study of the weak decay characteristics of 55 63Mn nuclides. The strength distributions of Gamow Teller transitions in the directions of decay and EC for these isotopes were calculated employing the proton neutron quasi particle random phase approximation (pn QRPA) model. The decay half life values of Mn isotopes under terrestrial conditions were computed and compared with measured data and previous calculations. The pn QRPA estimated half lives are in good agreement with the experimental values. The and EC rates were later calculated covering a large range of stellar temperatures (001 30) 109 K and densities (10 1011) g/cm3.
nucl-thastro-ph.SRNew Astron.(2023)·3 citations
03
Investigation of weak-rates for odd-A nuclei for presupernova simulations
Muhammad Riaz🇵🇰 · Jameel-Un Nabi🇵🇰 · Muhammad Majid🇵🇰
Calculating weak decay rates under stellar conditions for studying presupernova evolution of massive stars is a challenging task. Here we show the importance of odd A nuclei for presupernova simulations. In order to calculate the required nuclear matrix elements we apply the pn QRPA model in a deformed basis. Nuclear deformation, thought to play an integral role in calculation of associated weak decay rates, is taken into account in our model. We calculate Gamow Teller (GT) strength distributions, emission and positron capture rates for selected odd A nuclei. Our model does not employ the Brink Axel hypothesis as used in previous calculations of weak decay rates and we perform a state by state microscopic calculation of GT strength distributions from all parent excited states. Our calculated decay rates are in good agreement with large scale shell model calculations.
nucl-thBraz.J.Phys.(2021)·0 citations
04
Bayesian inferences on covariant density functionals from multimessenger astrophysical data: Nucleonic models
Jia-Jie Li (Southwest U., Chongqing) · Yu Tian (Southwest U., Chongqing) · Armen Sedrakian (FIAS, Frankfurt and U. Wroclaw)
[Background] Bayesian inference frameworks incorporating multi-messenger astrophysical constraints have recently been applied to covariant density functional (CDF) models to constrain their parameters. Among these, frameworks utilizing CDFs with density-dependent meson-nucleon couplings furnishing the equation of state (EoS) of compact star (CS) matter have been explored. [Purpose] The aforementioned inference framework has not yet incorporated astrophysical objects with potentially extreme high masses or ultra-small radii among its constraints, leaving its flexibility and predictive power under such extreme parameters still unknown. [Method] We apply the Bayesian inference framework based on CDFs with density dependent couplings. The astrophysical data is expanded to include not only the latest multi-messenger constraints from NICER and gravitational wave events but also the highest measured mass to date for the ``black widow" pulsar PSR J0952-0607 and the mass-radius estimates for the ultra-compact, low-mass object HESS J1731-347. [Results] Our systematic Bayesian analysis indicates that our CDF models can support higher maximum masses for CSs, reaching up to $2.4$ - $2.5 M_{⊙}$ . However, achieving sufficient softening of the EoS in the low-density regime to accommodate the HESS J1731-347 data remains challenging. Nonetheless, we are able to impose tighter constraints on the parameter space of CDF models, ensuring consistency with current nuclear experimental and astrophysical data. [Conclusions] CDF models with density-dependent meson-nucleon couplings encompass a wide range of nuclear and astrophysical phenomena, providing a robust theoretical framework for interpreting compact objects. However, the predicted lower limit for the radii of low-mass stars is approximately 12 km, which stems from the restricted degrees of freedom in the isovector sector.
nucl-thastro-ph.HEPRC(2025)·14 citations
05
The $η^{'} N$ interaction from the $η^{'} p$ correlation function
Natsumi Ikeno🇯🇵
We evaluate for the first time the $η^{'} p$ femtoscopic correlation function to study the $η^{'} N$ interaction. We find it extremely sensitive to the value of the $η^{'} p$ scattering length, for which at present there exists only very limited information, not even knowing its sign. The measurement of this correlation function would provide much valuable information on the $η^{'} N$ interaction, which could then also be used to settle the issue of possible $η^{'}$ nucleus bound states, an issue attracting much attention in the nuclear physics community.
nucl-thhep-exhep-phnucl-exEPJA(2025)·7 citations
06
Electromagnetic form factors of $^{6}$ Li, $^{7}$ Li, and $^{7}$ Be in cluster effective field theory
Son T. Nguyen
Effective field theory (EFT) provides a powerful model-independent theoretical framework for illuminating complicated interactions across a wide range of physics areas and subfields. In this work, we consider the low-energy deuteron-Helium-4, triton-Helium-4, and helion-Helium-4 systems at low energies in cluster EFT. In particular, we focus on the deuteron + Helium-4 cluster configuration of the Lithium-6 nucleus, the triton + Helium-4 cluster configuration of the Lithium-7 nucleus, and the Helium-3-Helium-4 configuration of the Beryllium-7 nucleus, respectively. We illustrate how to directly extract the asymptotic normalization coefficient and several observables using experimental measurement of the electromagnetic form factors of these nuclei.
nucl-th1 citation
07
Inferring the Equation of State from Neutron Star Observables via Machine Learning
N. K. Patra🇨🇳 · Tuhin Malik🇵🇹 · Helena Pais🇵🇹 · Kai Zhou🇨🇳 · B. K. Agrawal🇮🇳 · Constança Providência🇵🇹
We have conducted an extensive study using a diverse set of equations of state (EoSs) to uncover strong relationships between neutron star (NS) observables and the underlying EoS parameters using symbolic regression method. These EoS models, derived from a mix of agnostic and physics-based approaches, considered neutron stars composed of nucleons, hyperons, and other exotic degrees of freedom in beta equilibrium. The maximum mass of a NS is found to be strongly correlated with the pressure and baryon density at an energy density of approximately 800 MeV.fm $^{- 3}$ . We have also demonstrated that the EoS can be expressed as a function of radius and tidal deformability within the NS mass range 1-2 $M_{⊙}$ . These insights offer a promising and efficient framework to decode the dense matter EoS directly from the accurate knowledge of NS observables.
nucl-thastro-ph.HEastro-ph.SRgr-qc+1PLB(2025)·19 citations
08
Global Framework for Emulation of Nuclear Calculations
Antoine Belley · Jose M. Munoz · Ronald F. Garcia Ruiz
We introduce a hierarchical framework that combines ab initio many-body calculations with a Bayesian neural network, developing emulators capable of accurately predicting nuclear properties across isotopic chains simultaneously and being applicable to different regions of the nuclear chart. We benchmark our developments using the oxygen isotopic chain, achieving accurate results for ground-state energies and nuclear charge radii, while providing robust uncertainty quantification. Our framework enables global sensitivity analysis of nuclear binding energies and charge radii with respect to the low-energy constants that describe the nuclear force.
nucl-thcs.LGPRL(2026)·12 citations
09
Structure of center-vortex matter in SU(4) Yang-Mills theory
Jackson A. Mickley🇦🇺 · Derek B. Leinweber🇦🇺 · Luis E. Oxman🇧🇷
The structure of center vortices is studied in SU(4) Yang-Mills theory for the first time to illuminate the interplay between elementary (center charge $\pm 1$ ) and doubly charged vortices. Unlike in SU(3), where charge $+ 2$ vortices are simply elementary vortices with reversed orientations in spacetime, these possibilities are physically distinct in SU(4). Visualizations of the vortex structure in three-dimensional slices reveal the various ways in which doubly charged objects manifest, as the convergence and matching of elementary vortices or as isolated doubly charged loops. An algorithm is described to classify every doubly charged chain as one of these three types. A collection of vortex statistics is considered to quantify the vortex structure. Many of these pertain to the novel doubly charged objects, including their relative proportions and chain lengths, which are analyzed to highlight the differences between each chain type. Three different lattice spacings are employed to investigate the approach to the continuum limit. Vortex matching chains are found to be shorter on average but also more prevalent than vortex convergences, ascribed to their interpretation as extended center monopoles. In addition, the lengths of both vortex convergences and vortex matchings are observed to follow an exponential distribution, allowing the introduction of a constant probability for a doubly charged chain to split into two elementary vortices as it propagates. Combined, these findings provide a characterization of the vortices that comprise center-vortex structures in SU(4) Yang-Mills theory.
↳ hep-lathep-phhep-thnucl-thPRD(2025)·3 citations
10
Gross-Llewellyn Smith sum rule from lattice QCD
K. Utku Can🇦🇺 · Joshua A. Crawford🇦🇺 · Roger Horsley🇬🇧 · Paul E. L. Rakow🇬🇧 · Thomas G. Schar🇦🇺 · Gerrit Schierholz🇩🇪 · Hinnerk Stüben🇩🇪 · Ross D. Young🇦🇺 · James M. Zanotti🇦🇺
We compute the Gross-Llewellyn Smith sum rule, i.e. the lowest odd moment of the parity-violating structure function, $F_{3}$ , of the nucleon from a lattice QCD calculation of the Compton amplitude. Our calculations are performed on $4 8^{3} \times 96$ lattices at the $S U (3)$ symmetric point for two lattice spacings. We extract the moments for several values of the current momenta in the range $0.5 ≲ Q^{2} ≲ 10 GeV^{2}$ , covering both the nonperturbative and perturbative regimes. We compare our moments to the Gross-Llewellyn Smith sum rule and discuss the implications for higher-twist effects, a determination of $α_{s} (Q^{2})$ from a hadronic quantity complementing the phenomenological and other lattice approaches, and electroweak box contributions crucial for Cabibbo-Kobayashi-Maskawa matrix unitarity studies.
↳ hep-lathep-phnucl-exnucl-thPRD(2025)·3 citations
11
QCD Vacuum Energy and Its Implication for Quark Nugget Stability
Yang Bai🇺🇸 · Ting-Kuo Chen🇺🇸
In this work, we employ both theoretical and data-driven methods to derive the QCD vacuum energy, utilizing the GMOR relation, the low-energy theorem, and the equation of state from Lattice QCD. The QCD vacuum energy is determined to be between around $(163 \mbox M e V)^{4}$ and $(190 \mbox M e V)^{4}$ . With the assumptions of complete deconfinement, vanishing gluon condensate, full chiral-symmetry restoration, and the validity of perturbative QCD at baryon chemical potentials of order of the proton mass, a very specific kind of quark nugget is found to be less stable than ordinary nuclei.
↳ hep-phhep-latnucl-thPRD(2026)·8 citations
12
Generative adversarial neural networks for simulating neutrino interactions
Jose L. Bonilla🇵🇱 · Krzysztof M. Graczyk🇵🇱 · Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Beata E. Kowal🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱
We propose a new approach to simulate neutrino scattering events as an alternative to the standard Monte Carlo generator approach. Generative adversarial neural network (GAN) models are developed to simulate charged current neutrino-carbon collisions in the few-GeV energy range. We consider a simplified framework to generate muon kinematic variables, specifically its energy and scattering angle. GAN models are trained on simulation data from \nuwro{} Monte Carlo event generator. Two GAN models have been obtained: one simulating quasielastic neutrino-nucleus scatterings and another simulating all interactions at given neutrino energy. The models work for neutrino energy ranging from 300 MeV to 10 GeV. The performance of both models has been assessed using two statistical metrics. It is shown that both GAN models successfully reproduce the distribution of muon kinematics.
↳ hep-phcs.LGhep-exnucl-ex+1PRD(2025)·5 citations
13
Long-range interactions in double heavy tetraquarks $Q ˉ Q ˉ q q$
Muhammad Naeem Anwar🇬🇧
At the large distances compared to the chiral symmetry breaking scale, a four-quark system $Q ˉ Q ˉ q q$ (with $Q$ as heavy and $q$ as light quarks) can be treated as two asymptotic mesons interacting via strong residual forces. The static heavy quark assumption enables using the Born-Oppenheimer approximation, where one can compute the potential between two heavy antiquarks in the presence of two light quarks of finite mass -- a prescription utilized in several lattice QCD studies. To analyse the long-range strong force in a $Q ˉ Q ˉ q q$ system, we study the interaction between two bottom mesons in the heavy quark limit using chiral effective field theory and dispersion theory with unphysical pion mass. We present methods to obtain two-pion-exchange potential between two static heavy mesons at non-physical pion mass and compare our preliminary results with the corresponding lattice QCD potentials.
↳ hep-phhep-latnucl-thPoS(2025)·0 citations
14
Rotational Brownian motion and heavy quark polarization in QCD medium
Sourav Dey🇮🇳 · Amaresh Jaiswal🇮🇳
We consider the rotational Brownian motion of heavy quark in QCD medium and provide analytical results for polarization of open heavy-flavor hadrons. We calculate expressions for vector and tensor polarization, corresponding to baryon spin polarization and vector meson spin alignment, respectively. Assuming that heavy quarks are initially fully spin polarized along the direction of magnetic field, we compare our results with recent experimental data from ALICE collaboration for $D^{*+}$ meson and provide predictions for spin polarization of open charm baryons. We propose that the transverse momentum dependence of heavy quark polarization may serve as a distinctive signature of the intense initial magnetic field generated in off-central relativistic heavy-ion collisions.
↳ hep-phnucl-thPLB(2026)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE