Nuclear Theory·nucl-th

Tuesday·April 8, 2025

20 papers—9 primary·11 cross-listed

01
Determination of $S_{18}$ from $^{9}$ C breakup reaction within a four-body reaction model
Shoya Ogawa🇯🇵 · Tokuro Fukui🇯🇵 · Jagjit Singh🇬🇧 · Kazuyuki Ogata🇯🇵
The astrophysical factor $S_{18}$ for the $^{8}$ B( $p$ , $γ$ ) $^{9}$ C has indirectly been measured with the proton removal reactions from $^{9}$ C, elastic breakup of $^{9}$ C off a heavy target, and transfer reactions. Quite recently, the elastic breakup cross section data were reanalyzed with the continuum-discretized coupled channels method (CDCC) assuming a $p +^{8} B$ two-body model for $^{9}$ C and the $S_{18}$ was modified. It was not well justified, however, to treat $^{8}$ B as an inert nucleus given its proton separation energy is only 137~keV. We reexamine the elastic breakup of $^{9}$ C by the four-body CDCC with a $p + p +^{7} Be$ three-body model for $^{9}$ C and evaluate $S_{18}$ . To achieve this, we propose a method to disentangle the $p +^{8} B +^{208} Pb$ three-body channel in the four-body CDCC calculation, for the first time. We calculate the elastic breakup cross section of $^{9}$ C off a $^{208}$ Pb target at 65~MeV/nucleon. The obtained breakup cross sections are decomposed into the contributions of the $p +^{8} B +^{208} Pb$ and $p + p +^{7} Be +^{208} Pb$ channels by using the solution of the complex-scaled Lippmann--Schwinger equation. The breakup cross section to the $p +^{8} B +^{208} Pb$ channel reproduces well the shape of the experimental data in the low breakup energy region, which is important for determining $S_{18}$ . By fitting the theoretical result to the experimental data, the asymptotic normalization coefficient of $^{9}$ C for the $p +^{8} B$ configuration is determined and we obtain $S_{18} = 38.4 \pm 1.1$ eVb. This result is smaller than the previous value obtained with the three-body CDCC by about 45\%. Thus, our new results suggest the necessity of taking into account the fragile nature of $^{8}$ B in the $^{9}$ C breakup.
nucl-thPTEP(2026)·0 citations
02
Electromagnetic radii of light nuclei from variational Monte Carlo calculations
G. B. King🇺🇸 · G. Chambers-Wall🇺🇸 · A. Gnech🇺🇸 · S. Pastore🇺🇸 · M. Piarulli🇺🇸 · R. B. Wiringa🇺🇸
We present variational Monte Carlo calculations of charge and magnetic radii in $A \leq 10$ nuclei. The calculations are based on the Norfolk two- and three-nucleon interactions, and associated one- and two-nucleon electromagnetic charge and current operators derived up to next-to-next-to-next-to leading order in the chiral expansion. The charge and magnetic radii are extracted from the respective form factors. We find that the charge radii are within 5\% of the experimental values for the nuclei considered. For the magnetic radii, a comparison is available only with $^{3}$ H and $^{3}$ He electron scattering data that are affected by large error bars. We hope that our predictions foster an interest in precisely measuring magnetic radii of heavier systems.
nucl-thPRC(2025)·8 citations
03
Non-negligible influence of shape inheritance and staggering on {\alpha} decay
Ruixiong Li · Jingyu Xiao · Hongfei Zhang · Nana Ma
A series of findings in machine learning (ML) and decay theory are captured while exploring the role of deformation and preformation factors in {\alpha} decay. We provide a novel and practical paradigm for developing physics-driven machine learning in nuclear physics research by introducing known decay theory and statistical correlation analysis. Furthermore, this analysis verifies the Geiger-Nuttall law, and the relationship between the decay energy and {\alpha} formation amplitude, also releases a signal that nuclei with hexadecapole deformation are more likely to form {\alpha} clusters. In particular, we identify two novel phenomena, shape inheritance, in which the deformation properties are partially transmitted from parent to daughter nuclei; and half-life inversion due to shape staggering of adjacent even-even nuclei. This phenomenon occurs frequently in neutron-deficient nuclei near lead isotopes, which is consistent with shape coexistence in experiments. Surprisingly, it reappeared within the predicted half-life of the 119 and 120 isotope chains in the eighth period of the periodic table. The half-life considering the inversion effect is preferable for the study of new nuclides and shape coexistence in experiments.
nucl-th1 citation
04
Probability for synthesis of superheavy nuclei with Z=121
R. Zargini · S. A. Seyyedi
In this study the empirical method \cite{RN464} is used for calculating the evaporation residue (ER) cross section in the synthesis of superheavy nuclei (SHN). The superheavy nuclei examined in this work fall within the range $Z = 112 - 118$ . The theoretical calculations show good agreement with the experimental data. Furthermore, this model, along with an investigation of the optimal incident energy (OIE), is used to calculate the ER cross section for a hypothetical heavy system with $Z = 121$ . Five promising combinations are suggested for synthesis of SHN with $Z = 121$ : (1) $^{50} Ti +^{252} Es$ , with the maximum ER cross section $σ_{3 n} = 24.5 fb$ , at the optimal incident energy, $OIE = 230 MeV$ ; (2) $^{50} Ti +^{254} Es$ , with the maximum ER cross section $σ_{3 n} = 11.8 fb$ , at the optimal incident energy, $OIE = 229 MeV$ ; (3) $^{51} V +^{251} Cf$ , with the maximum ER cross section $σ_{3 n} = 1.2 fb$ , at the optimal incident energy, $OIE = 238 MeV$ ; (4) $^{51} V +^{249} Cf$ , with the maximum ER cross section $σ_{3 n} = 1.0 fb$ , at the optimal incident energy, $OIE = 238 MeV$ ; and (5) $^{54} Cr +^{247} Bk$ , with the maximum ER cross section $σ_{2 n} = 0.9 fb$ , at the optimal incident energy, $OIE = 243 MeV$ .
nucl-thPRC(2025)·0 citations
05
Harmonic Oscillator Representation of Scattering Theory in the Presence of Coulomb Potential
Ustin M Yanikov🇷🇺 · Vasily A Kulikov🇷🇺 · Andrey M Shirokov🇷🇺
Considering the problem of scattering of charged particles, we introduce a new approach of taking the Coulomb interaction into account within the HORSE formalism. Compared to the conventional HORSE approach for uncharged particles, we add a diagonal Coulomb term to} the three-term recurrent relation for expansion coefficients in the asymptotic region. The method simplifies calculations and demonstrates a good agreement with numerical solution.
nucl-thJ.Subatomic Part.Cosmol.(2025)·3 citations
06
Examination of the lattice QCD-motivated strong attractive $Ω N$ potentials in the $Ω^{-} n p$ system
I. Filikhin🇺🇸 · R. Ya. Kezerashvili🇺🇸 · B. Vlahovic🇺🇸
Within the framework of the Faddeev equations in configuration space, we examine the $Ω^{-} n p$ system, employing strongly attractive lattice HAL QCD and Yukawa-type meson exchange potentials for the $Ω N$ interaction. Our formalism incorporates the attractive Coulomb force between the $Ω^{-}$ and proton, treating the system as three non-identical particle pairs (the $A B C$ model). In this study, we assess the impact of the Coulomb interaction on the system and compare our results with recent $Ω N N$ ( $AA C$ model) calculations obtained using various approaches. The $A B C$ model yields low-energy characteristics for the $\Omega NN$ system that differ from previous calculations. The Coulomb potential has a marginal perturbative effect on the $AA C$ system, shifting the three-body binding energy by the Coulomb energy of the two-body $B C$ subsystem, but only slightly deviating the spatial configuration from isosceles triangle symmetry. These effects are primarily driven by the strong $\Omega N$ interaction. We demonstrate that the large binding energy of the $Ω^{-} n p$ system arises from the short-range behavior of the $Ω N$ potentials.
nucl-thhep-latPRD(2025)·4 citations
07
Identifying $α$ -cluster configurations in $^{20}$ Ne via ultracentral Ne+Ne Collisions
Pei Li🇨🇳 · Bo Zhou🇨🇳 · Guo-Liang Ma🇨🇳
The initial-state geometry in relativistic heavy-ion collisions provides a novel probe to nuclear cluster structure. For $^{20}$ Ne, a novel approach is proposed to distinguish between the cluster configurations (5 $α$ versus $α +^{16}$ O) in order to gain insight into nuclear structure transitions governed by many-body quantum correlations. Through analytical calculations with the microscopic Brink model and event-by-event simulations using the hydrodynamic framework, we establish the normalized symmetric cumulant NSC (3, 2) and the Pearson coefficient $ρ_{2} (v_{2}^{2}, δ [p_{T}])$ as quantitative discriminators to reveal enhanced cluster degrees of freedom in the ground state of $^{20}$ Ne. The ultracentral Ne+Ne collisions at the LHC can experimentally identify these two competing configurations via these flow correlation observables, opening a new paradigm for probing clustering in light nuclei.
nucl-thhep-phnucl-exPRL(2026)·15 citations
08
Fermi Operator Expansion for the Hartree-Fock-Bogoliubov Theory
Chengpeng Yu🇯🇵 · Takashi Nakatsukasa🇯🇵
A variety of phases in the inner crust of neutron stars are crucial for understanding the pulsar phenomena. However, the three-dimensional coordinate-space calculation of the phases is computationally demanding. We aim to generalize the Fermi operator expansion (FOE) method that is effective for finite-temperature coordinate-space simulation, from the Hartree-Fock theory to Hartree-Fock-Bogoliubov (HFB) theory including the pairing effects. Furthermore, the periodic structure with free neutrons in the inner crust requires us to treat the system with the band theory. We give a concise proof that the generalized density matrix in the HFB theory can be obtained with the FOE. The Chebyshev polynomial expansion is used for calculations of the HFB band theory. Using a model for a slab phase of the inner crust, the FOE method produces results in good agreement with those based on the diagonalization of the HFB Hamiltonian. The FOE method for the HFB band theory is a powerful tool for studying the nontrivial exotic structures in neutron stars. The FOE method is suitable for parallelization and further acceleration is possible with nearsightedness.
nucl-thPRC(2025)·0 citations
09
The role of the screening potential in the deuteron-deuteron thermonuclear reaction rates
Faisal Etminan🇮🇷
The deuteron-deuteron (D-D) thermonuclear reaction rates in metallic environments (considering the electron screening effects) is calculated using the S-factor functions which were obtained by fitting to low-energy data on D-D reactions. For this purpose, a fitted S-factor model based on the NACRE compilation is employed. This limited the energy range of Big Bang nucleosynthesis (BBN) for the $^{2} H (d, p)^{3} H$ and $^{2} H (d, n)^{3} He$ reactions. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from $1 0^{6}$ K to $1 0^{10} (or 1.3 \times 1 0^{8})$ K are provided in tabular formats. In these evaluations, the screening energy ( $U_{e}$ ) is assumed to be $100, 400, 750, 1000$ eV and $1250$ eV. This series of values has been selected based on theoretical and experimental studies conducted so far. % Eventually, our numerical analysis suggests that the ratio of the reaction rate with the screening potential to the reaction rate without the screening potential, can be described by the term $exp (4.70 + 6.50 U_{e} / T_{9})$ for both $^{2} H (d, p)^{3} H$ and $^{2} H (d, n)^{3} He$ reactions. This series of values has been selected based on theoretical and experimental studies conducted so far.
nucl-thnucl-exNPA(2026)·0 citations
10
Color superconductivity under neutron-star conditions at next-to-leading order
Andreas Geißel🇩🇪 · Tyler Gorda🇩🇪 · Jens Braun🇩🇪
The equation of state of deconfined strongly interacting matter at high densities remains an open question, with effects from quark pairing in the preferred color-flavor-locked (CFL) ground state possibly playing an important role. Recent studies suggest that at least large pairing gaps in the CFL phase are incompatible with current astrophysical observations of neutron stars. At the same time, it has recently been shown that in two-flavor quark matter, subleading corrections from pairing effects can be much larger than would be naïvely expected, even for comparatively small gaps. In the present Letter, we compute next-to-leading-order corrections to the pressure of quark matter in the CFL phase arising from the gap and the strong coupling constant, incorporating neutron-star equilibrium conditions and current state-of-the-art perturbative QCD results. We find that the corrections are again quite sizable, and they allow us to constrain the CFL gap in the quark energy spectrum to $Δ_{CFL} ≲ 140 MeV$ at a baryon chemical potential $μ_{B} = 2.6 GeV$ , even when allowing for a wide range of possible behaviors for the dependence of the gap on the chemical potential.
↳ hep-phnucl-thPRL(2025)·23 citations
11
Fragmentation functions for axial-vector heavy tetraquarks: A TQ4Q1.1 update
Francesco Giovanni Celiberto🇪🇸
We present and discuss the release of novel sets of collinear, variable-flavor-number-scheme fragmentation functions for axial-vector, fully heavy $T_{4 c} (1^{+-})$ and $T_{4 b} (1^{+-})$ tetraquarks. Working within the single-parton approximation at leading power and employing nonrelativistic QCD factorization adapted for tetraquark Fock states, we model the initial-scale fragmentation input using a recent calculation for the constituent heavy-quark channel. Standard DGLAP evolution is then applied, ensuring consistent implementation of evolution thresholds. To support phenomenology, we investigate NLL/NLO $^{+}$ rates for tetraquark-jet systems at the HL-LHC and FCC from (sym)JETHAD. This study further integrates exotic matter explorations with precision QCD calculations.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·18 citations
12
Nuclear Physics and the European Particle Physics Strategy Update 2026
L.M. Fraile🇪🇸 · J.J. Gaardhøje🇩🇰 · U. van Kolck🇮🇹 · H. Moutarde🇫🇷 · N. Patronis🇬🇷 · M.T. Peña🇵🇹 · L. Popescu🇧🇪 · V. Wagner🇨🇿 · E. Widmann (on behalf of NuPECC)🇦🇹
This document provides input to the update of the European Strategy for Particle Physics in fields that are related to Nuclear Physics as described in the NuPECC Long Range Plan 2024 (arXiv:2503.15575).
↳ nucl-exnucl-th0 citations
13
Study of nucleon and $Δ$ resonances from a systematic analysis of $K^{*} Σ$ photoproduction
Jun Shi🇨🇳 · Bing-Song Zou🇨🇳
A systematic analysis of the $K^{*} Σ$ photoproduction off proton is performed with all the available differential cross section data. We carry out a strategy different from the previous studies of these reactions, where, instead of fixing the parameters of the added resonances from PDG or pentaquark models, we add the resonance with a specific $J^{P}$ and leave its parameters to be determined from the experimental data. When adding only one resonance, the best result is to add one $N (3/ 2^{-})$ resonance around $2097$ MeV, which substantially reduces the $χ^{2}$ per degree of freedom to $1.35$ . There are two best solutions when adding two resonances, one is to add one $N^{*} (3/ 2^{-})$ and one $N^{*} (7/ 2^{-})$ , the other is to add one $N^{*} (3/ 2^{-})$ and one $Δ^{*} (7/ 2^{-})$ , leading the $χ^{2}$ per degree of freedom to be $1.10$ and $1.09$ , respectively. The mass values of the $N^{*} (3/ 2^{-})$ in the two resonance solutions are both near $2070$ MeV. Our solutions indicate that the $N (3/ 2^{-})$ resonance around $2080$ MeV is strongly coupled with the $K^{*} Σ$ final state and support the molecular picture of $N (2080, 3/ 2^{-})$ .
↳ hep-phnucl-thPRD(2025)·2 citations
14
Transverse-momentum-dependent pion structures from lattice QCD: Collins-Soper kernel, soft factor, TMDWF, and TMDPDF
Dennis Bollweg🇺🇸 · Xiang Gao🇺🇸 · Jinchen He🇺🇸 · Swagato Mukherjee🇺🇸 · Yong Zhao🇺🇸
We present the first lattice quantum chromodynamics (QCD) calculation of the pion valence-quark transverse-momentum-dependent parton distribution function (TMDPDF) within the framework of large-momentum effective theory (LaMET). Using correlators fixed in the Coulomb gauge (CG), we computed the quasi-TMD beam function for a pion with a mass of 300 MeV, a fine lattice spacing of $a = 0.06$ fm and multiple large momenta up to 3 GeV. The intrinsic soft functions in the CG approach are extracted from form factors with large momentum transfer, and as a byproduct, we also obtain the corresponding Collins-Soper (CS) kernel. Our determinations of both the soft function and the CS kernel agree with perturbation theory at small transverse separations ( $b_{⊥}$ ) between the quarks. At larger $b_{⊥}$ , the CS kernel remains consistent with recent results obtained using both CG and gauge-invariant TMD correlators in the literature. By combining next-to-leading logarithmic (NLL) factorization of the quasi-TMD beam function and the soft function, we obtain $x$ -dependent pion valence-quark TMDPDF for transverse separations $b_{⊥} ≳ 1$ fm. Interestingly, we find that the $b_{⊥}$ dependence of the phenomenological parameterizations of TMDPDF for moderate values of $x$ are in reasonable agreement with our QCD determinations. In addition, we present results for the transverse-momentum-dependent wave function (TMDWF) for a heavier pion with 670 MeV mass.
↳ hep-lathep-exhep-phnucl-ex+1PRD(2025)·33 citations
15
Perturbation theory of rotating scalar fields and vacuum insensitivity to rotation
Ryo Kuboniwa🇯🇵 · Kazuya Mameda🇯🇵
We formulate the finite-temperature perturbation theory of interacting scalar fields under external rotation. Because of the translational non-invariance in the radial direction, Green's functions are described using the Fourier-Bessel basis, instead of the conventional Fourier basis. We derive the leading-order correction to the partition function and the one-loop self-energy. The Feynman rules obtained in our perturbation theory shows that due to the finite-size effect required by the causality constraint, the zero-temperature thermodynamics in the perturbation theory is unaffected by rotation, similarly to that in the noninteracting theory.
↳ hep-thhep-phnucl-thPLB(2026)·7 citations
16
Charmonium-nucleon femtoscopic correlation function
Zhi-Wei Liu🇨🇳 · Duo-Lun Ge🇨🇳 · Jun-Xu Lu🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳
This study investigates the femtoscopic correlation functions of charmonium-nucleon pairs, utilizing the lattice QCD phase shifts provided by the HAL QCD Collaboration. A ``model-independent'' formalism is employed to transform scattering phase shifts directly into momentum correlation functions, thereby circumventing the approximations inherent in traditional methods, such as the Lednický-Lyuboshits model. The $J / ψ$ - $p$ correlation functions, including spin-averaged and partial-wave results, are predicted using near-physical pion mass lattice results. The $η_{c}$ - $p$ correlation function is calculated for the first time. The derived correlation functions provide critical references for future experiments, such as those at the LHC, where high-precision measurements of charmonium-nucleon correlations could unveil valuable insights into non-perturbative QCD dynamics.
↳ hep-phnucl-thPRD(2025)·16 citations
17
Investigation of the baryon time-like electromagnetic form factors in the electron-positron annihilation reactions
Ju-Jun Xie · Cheng Chen
Based on the experimental measurements of the electron-positron annihilation reactions into a baryon ( $B$ ) and anti-baryon ( $B ˉ$ ) pair, the electromagnetic form factors of hyperons in the time-like region can be investigated within the vector meson dominance model. The theoretical model parameters are determined by fitting them to the total cross sections of the process $e^{+} e^{-} \to B B ˉ$ , and it is found that the current experimental data on the baryon electromagnetic form factors in the time-like region can be well reproduced. In addition to the total cross sections, the electromagnetic form factors $G_{E}$ and $G_{M}$ , and the charge radii of those baryons are also estimated, which are in agreement with the experimental data. On the other hand, we have also investigated the nonmonotonic behavior of the time-like baryon electromagnetic form factors, and it is found that the previously proposed periodic behaviour of the nucleon time-like electromagnetic form factor is not confirmed. However, we do observe the nonmonotonic structures in the line shape of the baryon effective form factors or the ratio $∣ G_{E} / G_{M} ∣$ for the charmed baryon $Λ_{c}^{+}$ . These features can be naturally explained by incorporating contributions from excited vector states. More precise measurements of the $e^{+} e^{-} \to B B ˉ$ reaction offer a valuable opportunity to probe the properties of excited vector states, which are at present poorly known. Additionally, comprehensive theoretical and experimental studies of baryon timelike electromagnetic form factors can provide critical insights into the underlying mechanisms of electron-positron annihilation processes.
↳ hep-phhep-exnucl-exnucl-thPoS(2025)·0 citations
18
Finite density signatures of confining and chiral dynamics in QCD thermodynamics and fluctuations of conserved charges
Yi Lu🇨🇳 · Fei Gao🇨🇳 · Yu-xin Liu🇨🇳 · Jan M. Pawlowski🇩🇪
We evaluate thermodynamic observables such as pressure, baryon number, entropy and energy density, as well as the second and fourth order baryon number cumulants in the phase structure of QCD. The intertwined confinement and chiral dynamics is resolved within functional QCD, aiming for quantitative accuracy at larger densities. Specifically it is shown that the self-consistent resolution of the confining gluonic background is crucial in particular for even the qualitative properties of the cumulants. Our results are in quantitative agreement with lattice and functional QCD benchmarks at vanishing and small chemical potentials. Moreover, they offer novel insights in the dynamics at larger chemical potentials including the regime of the critical end point. A welcome by-product of this analysis is the computation of the Polyakov loop potential in finite density QCD, which, alongside the aforementioned observables, can be used as input and benchmark for effective theory computations at finite density.
↳ hep-phhep-thnucl-exnucl-thPRD(2026)·31 citations
19
One-loop transverse-momentum-dependent soft function at higher orders in the dimensional regulator
Hua-Sheng Shao🇫🇷 · Guoxing Wang🇫🇷
The transverse-momentum-dependent (TMD) soft function for a generic hadroproduction process involving massive colored particles is analytically calculated at the one-loop level, extended to higher orders in the dimensional regulator $ϵ$ . We present both the azimuthal-angle-averaged and azimuthal-angle-dependent soft functions in impact-parameter space, making them suitable for small $q_{T}$ resummation calculations. Their analytic expressions are provided in terms of multiple polylogarithms. Our results offer essential ingredients for a complete higher-order perturbative calculation of the TMD soft function.
↳ hep-phnucl-thJHEP(2025)·6 citations
20
Precision DIS thrust predictions for HERA and EIC
June-Haak Ee🇺🇸 · Daekyoung Kang🇨🇳 · Christopher Lee🇺🇸 · Iain W. Stewart🇺🇸
We present predictions for the DIS 1-jettiness event shape $τ_{1}^{b}$ , or DIS thrust, using the framework of Soft Collinear Effective Theory (SCET) for factorization, resummation of large logarithms, and rigorous treatment of nonperturbative power corrections, matched to fixed-order QCD away from the resummation region. Our predictions reach next-to-next-to-next-to-leading-logarithmic (N $^{3}$ LL) accuracy in resummed perturbation theory, matched to $O (α_{s}^{2})$ fixed-order QCD calculations obtained using the program NLOJet++. We include a rigorous treatment of hadronization corrections, which are universal across different event shapes and kinematic variables $x$ and $Q$ at leading power, and supplement them with a systematic scheme to remove $O (Λ_{QCD})$ renormalon ambiguities in their definition. The framework of SCET allows us to connect smoothly the nonperturbative, resummation, and fixed-order regions, whose relative importance varies with $x$ and $Q$ , and to rigorously estimate theoretical uncertainties, across a broad range of $x$ and $Q$ covering existing experimental results from HERA as well as expected new measurements from the upcoming Electron-Ion-Collider (EIC). Our predictions will serve as an important benchmark for the EIC program, enabling the precise determination of the QCD strong coupling $α_{s}$ and the universal nonperturbative first moment parameter $Ω_{1}$ .
↳ hep-phnucl-thJHEP(2025)·10 citations

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