arXiv subjects

Zhongzhou Ren

Publications and source records attributed to Zhongzhou Ren.

At least 19 recordsLinked to original sources

arXiv2026

Kolmogorov-Arnold networks in nuclear binding energy prediction

This study explores the application of Kolmogorov-Arnold networks (KANs) in predicting nuclear binding energies, leveraging their ability to decompose complex multiparameter systems into simpler univariate functions. By utilizing data from the Atomic Mass Evaluation (AME2020) and incorporating features such as atomic number, neutron number, and shell effects, KANs achieved a significant lower root mean square error (0.26 MeV), surpassing traditional models. The symbolic regression analysis yielded simplified analytical expressions for binding energies, aligning with classical models like the liquid drop model and the Bethe-Weizsaecker formula. These results highlight KANs' potential in enhancing the interpretability and understanding of nuclear phenomena, paving the way for future applications in nuclear physics and beyond.

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arXiv2026

Channel couplings redirect absorbed flux from peripheral loss to fusion in weakly bound nuclear reactions

In reactions of weakly bound nuclei, the absorption cross section mixes two physically distinct contributions: inner capture associated with compound-nucleus formation, and peripheral losses from breakup, transfer, and other direct reactions. Within a framework that combines an ingoing-wave boundary condition (IWBC) at an inner radius with a complex potential in the external region, we derive the exact flux identity $σ_{\rm abs}=σ_{\rm fusion}+σ_W$ from the radial continuity equation. The resulting partition is exact within the adopted CC/CDCC model space and provides a practical diagnostic of where absorbed flux is removed. Applied to $^6$Li+$^{209}$Bi, the analysis reveals that channel couplings qualitatively reorganize the absorbed flux: the dominant absorption mechanism shifts from peripheral loss at sub-barrier energies to inner capture above the barrier, whereas the single-channel baseline remains peripheral-loss dominated throughout. The resulting IWBC-defined inner-capture cross section tracks the measured complete-fusion excitation function with only a modest dependence on the chosen boundary radius. Together with the exact identity $σ_{\rm abs}=σ_{\rm fusion}+σ_W$, this agreement supports interpreting the peripheral term $σ_W$ as a major spatial contributor to the well-known CF suppression in weakly bound systems.

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arXiv2026

Exact construction and uniqueness of the coupled-channel Green's function

We present a rigorous construction and uniqueness proof of the matrix Green's function for coupled radial Schrodinger equations with symmetric coupling potentials. The Green's matrix $G(R,R')$ is built from two fundamental sets of $N$ linearly independent solutions, regular and outgoing, of the coupled radial equations. We prove that the associated Wronskian matrix is diagonal with elements $W_n = -k_n$ and independent of the radial coordinate, and demonstrate through the symplectic structure of the $2N$-dimensional phase space that the resulting construction is the unique Green's matrix satisfying the defining equation with correct boundary conditions, continuity at the source point, and the prescribed derivative discontinuity. The construction applies to any system of coupled radial Schrodinger equations with symmetric coupling potentials and open channels, including coupled-channels problems arising in nuclear, atomic, and molecular scattering. As an illustrative application, we show how the Green's matrix enters the nonlocal dynamical polarization potential within the continuum-discretized coupled-channels framework, where retaining the off-diagonal elements captures multistep excitation pathways beyond the weak-coupling approximation.

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arXiv2026

Coherent Absorption Dynamics: The Dual Role of Off-Diagonal Couplings in Weakly Bound Nuclei

Disentangling reaction mechanisms in weakly bound nuclei remains a long-standing challenge, complicated by the common practice of treating absorption as an incoherent sum of channel contributions. Within the continuum-discretized coupled-channels (CDCC) framework, we apply the generalized optical theorem [Nucl. Phys. A 842, 48 (2010)] and show that the total absorption cross section, $σ_A \propto -\langleΨ|W|Ψ\rangle$, decomposes as $σ_A = σ_D + σ_B + σ_{int}$, where $σ_{int}$ is a coherent interference term between channel components. For the systems and complex fragment-target optical potentials considered, $σ_{int}$ is negative and comparable in magnitude to the direct absorption terms. The off-diagonal imaginary couplings play a dual role: they redistribute flux among channels and generate $σ_{int}$, which is required for flux-balance consistency. In calculations for $d+^{93}$Nb and $^6$Li$+^{59}$Co/$^{208}$Pb, retaining the full non-diagonal coupling matrix nearly doubles the breakup-channel absorption for the heavy target, while reducing the total absorption through $σ_{int}$. Neglecting the off-diagonal imaginary couplings $W_{ij}$ ($i \neq j$) is not merely an approximation but leads to a systematically biased physical picture: the total absorption is overestimated while the breakup absorption component is severely underestimated. Experimental analyses that employ incoherent-sum models to extract direct and breakup cross sections from data will inherit this bias. The full coupling matrix is therefore essential for mechanism-resolved cross-section extraction, and we advocate that experimentalists adopt full-coupling CDCC calculations as the standard for consistent interpretation of absorption data in weakly bound systems.

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arXiv2026

Exact Treatment of Continuum Couplings in Nuclear Optical Potentials via Feshbach Theory

We present a full-coupling construction of the Feshbach effective interaction in a converged continuum-discretized coupled-channels (CDCC) calculation. The method retains the complete Green's function in the excluded continuum space, treating the continuum-continuum couplings to all orders within the discretized CDCC model space, and therefore yields an explicitly non-local dynamic polarization potential. Applied to $d+^{58}$Ni scattering, the projected two-body potential reproduces the parent CDCC elastic observables and gives a reasonable description of the available experimental data, providing a direct numerical check of the projection. The resulting non-local potential exposes the spatial structure generated by virtual breakup, continuum propagation, and absorption in the continuum. Through the generalized optical theorem, we quantify the continuum-coupling contribution to the elastic flux loss and compare it with the elastic-breakup cross section over a broad incident-energy range. The calculation shows that the elastic-breakup fraction increases with energy, whereas the additional absorption associated with continuum components is strongest at intermediate energies.

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arXiv2026

Theoretical calculations on half-lives of spontaneous one-proton radioactivity

Research on the unstable nuclei beyond the nucleon drip line is an important method to study the nuclear interaction and structure in the extremely neutron-deficient or rich systems. Various nuclides beyond the proton drip line mainly decay through spontaneous one-proton emission. Using deformed Woods-Saxon potential, spin-orbit potential, and expanded Coulomb potential to construct the daughter-proton potential, the half-life data of various proton emitters are systematically calculated based on the quantum tunneling model and the microscopic Gamow state theory. By using nuclear data from different sources and comparing them with the measurements, the dependence of proton emission on decay energy and spectroscopic factors is evaluated. Additionally, based on previous observations, the half-life of the possibly lighter proton emitter in the fpg-shell below has been theoretically predicted. Our results are compiled into a comprehensive dataset of half-lives for both experimentally confirmed emitters (50 < Z < 84) and theoretically predicted emitters (30 < Z < 50), providing a useful reference for future experimental investigations related to the proton drip line. The datasets presented in this paper, including our results of calculation, are openly available at https://www.doi.org/10.57760/sciencedb.27551.

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arXiv2026

Coulomb bridge mechanism for peripheral polarization of weakly bound projectiles

We identify the matrix elements that carry peripheral polarization of weakly bound projectiles through the Feshbach dynamical polarization potential (DPP) within the continuum-discretized coupled-channels (CDCC) framework. Splitting the two P-Q bridge couplings into nuclear and Coulomb parts, while keeping a single Q-space propagator common to every term, decomposes the DPP into a nuclear, a Coulomb, and an interference component, $ΔU_{\rm DPP}=ΔU_N+ΔU_C+ΔU_{NC}$. Applied to $d+{}^{58}$Ni, ${}^{6}$Li$+{}^{208}$Pb, ${}^{11}$Be$+{}^{64}$Zn, and ${}^{8}$B$+{}^{64}$Zn, the decomposition reveals a controlled hierarchy: a nuclear bridge in the light system, a mixed bridge with strong destructive interference in the heavy stable case, and a Coulomb-dominated bridge in both halo systems, with the proton halo showing constructive nuclear-Coulomb interference. For the halo reactions, peripheral partial waves ($L\gtrsim 35$) satisfy $σ_R^L\simeqσ_{\rm DPP}^L\simeqσ_{\rm BU}^L$, with the high-$L$ DPP tail dominated by $σ_C^L$. Two diagnostic calculations isolate the responsible matrix elements: removing the off-diagonal Coulomb propagation inside Q leaves the pattern essentially intact, whereas removing the Coulomb part of the P-Q bridge collapses both DPP-induced absorption and breakup. The peripheral polarization of halo reactions is therefore a Coulomb-bridge effect, and the high-$L$ elastic-breakup yield serves as its observable signature.

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arXiv2026

Three-Body Barrier Dynamics of Double-Alpha Decay in Heavy Nuclei

The simultaneous emission of two $α$ particles--double-$α$ decay--represents a long-predicted but unobserved mode of nuclear radioactivity. Here we formulate this process as a genuine three-body problem within the hyperspherical coordinate framework and evaluate decay probabilities by numerically solving the corresponding hyperradial Schrödinger equation, combined with large-scale random sampling of the potential parameters; the latter treatment ensures that the present results are more convincing. Inspired by this, we demonstrate that the penetrability ratio between simultaneous and sequential $α$ emission exhibits a strikingly linear dependence on $ZQ_{αα}^{-1/2}$, extending the barrier penetration dynamics into the correlated few-body regime. The nuclei $^{108}$Xe, $^{218}$Ra, $^{224}$Pu, $^{222}$U, $^{216}$Rn, and $^{220}$Th are suggested as the most promising candidates for the observation of double-$α$ decay, with predicted half-lives potentially accessible within present detection limits. Our results provide a unified framework for multi-$α$ decay and open a pathway to probing nuclear clustering and few-body correlations in heavy nuclei.

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arXiv2025

Nucleon momentum distributions of complex nuclei from inclusive electron scattering

Nucleon momentum distributions (NMDs) reveal essential information about Fermi motion and short-range correlations (SRCs). In extracting NMDs from inclusive electron scattering data, theoretical analyses, such as the scaling analysis, are typically employed. For complex nuclei, consistently treating the excitation energy of the residual system is a complicated task, leading to discrepancies between existing extracted NMDs and ab initio calculations, particularly around the Fermi momentum $k_F$. To address this issue, we introduce an improved description of the excitation energy in the framework of the relativistic Fermi gas (RFG) model. With this treatment, the extracted NMDs of complex nuclei show better agreement with ab initio calculations across the low- and high-momentum range, especially around $k_F$, successfully reproducing both the behaviors of Fermi motion and SRCs. These results provide a new experimental perspective on the interplay between Fermi motion and SRCs in complex nuclei.

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arXiv2025

Spontaneous fission half-lives for heavy and super-heavy nuclei from phenomenological models

A phenomenological model is proposed for a systematic description of the spontaneous fission (SF) half-lives $T_{\rm SF}$ of heavy and super-heavy nuclei. Based on the effective tunneling barrier (ETB), the proposed approach reproduces the SF half-lives of 79 known nuclei with an average deviation of 0.8, which is $17\%$ smaller than that of the linear correlation approach recently proposed in [N. S. Moiseev, N. V. Antonenko and G. G. Adamian, Phys. Rev. C 112, 034607 (2025)]. For superheavy nuclei with $45\leqslant N-Z \leqslant 61$, the predicted SF half-lives from these two different phenomenological models are in good agreement with each other. The ETB calculations implies that the $β$-decay energy affects the SF half-lives of nuclei far from the $β$-stability line. For superheavy nuclei around the magic number $N=184$, the predicted $T_{\rm SF}$ of $^{304}$120 is much shorter than that of $^{298}$Fl. With predicted values of about $10 \sim 160$ ms for $T_{\rm SF}$, the unmeasured SHN $^{293}119 $ could survive for long enough to reach the focal-plane detector in detection systems like the gas-filled recoil separator SHANS in Lanzhou.

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arXiv2025

Ground-state properties of finite nuclei in relativistic Hartree-Bogoliubov theory with an improved quark mass density-dependent model

A relativistic Hartree-Bogoliubov (RHB) model based on quark-meson coupling is developed, with a new parametrization derived from experimental observables. Using this model, we systematically investigate the ground-state properties of even-even nuclei spanning $8\leq Z\leq118$, including binding energies, quadrupole deformations, root-mean-square (rms) charge radii, two-nucleon separation energies, two-nucleon shell gaps, and $α$-decay energies. Comparisons with available experimental data demonstrate that this subnucleon-based RHB model reliably describes the ground-state properties of finite nuclei.

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arXiv2025

Data-driven trap theory for nuclear scattering

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-α 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.

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arXiv2025

Enhancement of primordial curvature perturbations in $R^3$-corrected Starobinsky-Higgs inflation

We provide a systematic study of the Starobinsky-Higgs inflation model in the presence of an additional cubic term of the Ricci scalar. We investigate, in particular, the effects of the cubic term on the spectral index $n_s$ and the tensor-to-scalar ratio $r$. Through both analytical and numerical analyses, we show that the $R^3$-corrected Starobinsky-Higgs model can achieve compatibility with cosmic microwave background observations while producing distinct observational signatures with different frequency ranges. In addition, we discuss the complementarity between different observational probes, including the scalar-induced gravitational waves and spectral distortions, offering an independent probe of the enhanced curvature perturbations. Detection prospects are also discussed.

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arXiv2025

Studying few cluster resonances with quantum neural network driven iterative Harrow-Hassidim-Lloyd algorithm

By using the quantum computing the properties of hypernuclei ${}^5_Λ$He, ${}^{\ 6}_{ΛΛ}$He and ${}^9_Λ$Be can be investigated within microscopic cluster model. Our approach combines quantum neural network (QNN) with iterative Harrow-Hassidim-Lloyd (IHHL) algorithm (abbreviated as QNN-IHHL) to solve the quantum many-body problem. To efficiently describe resonance phenomena, we employ complex scaling and eigenvector continuation techniques, providing a robust framework for identifying few-cluster resonance parameters within quantum computing. To validate our quantum algorithm, the resonant $4^{+}$ state of ${}^9_Λ$Be is chosen as a core example. With QNN-IHHL algorithm we realize a fully quantum workflow, which provides a novel framework and some ground work for exploring resonance properties in complex nuclear many-body systems.

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arXiv2025

Iterative Harrow-Hassidim-Lloyd quantum algorithm for solving resonances with eigenvector continuation

We propose a novel quantum algorithm for solving nuclear resonances, which is based on the iterative Harrow-Hassidim-Lloyd algorithm and eigenvector continuation with complex scaling. To validate this approach, we compute the resonant states of $α-α$ system and achieve results in good agreement with traditional methods. Our study offers a new perspective on calculating eigenvalues of non-Hermitian operators and lays some groundwork for further exploration of nuclear resonances using quantum computing.

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arXiv2025

Charged-current quasielastic neutrino scattering off nuclei with nucleon-nucleon short-range correlations

In recent years, many studies on neutrino-nucleus scattering have been carried out to investigate nuclear structures and the interactions between neutrinos and nucleons. This paper develops a charged-current quasielastic (CCQE) neutrino-nucleus scattering model to explore the nuclear mean-field dynamics and short-range correlation effects. In this model, the nuclear structure effect is depicted using the scaling function, while the neutrinonucleon interaction is represented by the elementary weak cross section. Results indicate that the double-differential cross section of scattered muon is influenced by the energy and momentum of nucleon in nuclei, and the total cross section depends primarily on the incident neutrino energy. Furthermore, incorporating short-range correlations yields the flux-integrated differential cross sections at high-T region producing larger values, a longer tail, and achieving better experimental consistency. It eventually elucidates the physical relationship between the neutrinonucleus scattering cross section and the variation in incident neutrino energy. The studies in this paper furnishes insights for the research of nucleon dynamics and provides detailed examinations of the neutrino-nucleus scattering mechanism.

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arXiv2025

Nuclear $α$-cluster structures from valence-space microscopic cluster model

Alpha clustering is an important dynamic in nuclear physics, with growing interest to its study in heavy nuclei in recent years. Theoretically, the microscopic cluster models taking nucleons as relevant degrees of freedom have been widely used to study $α$-cluster structures in light nuclei. However, a straightforward application on same footing in heavy nuclei is obstructed by the complexity of handling numerous nucleons. As a simplified alternative, the macroscopic cluster models built upon cluster degrees of freedom are usually employed in heavy nuclei, though these approaches typically lose several critical structural details. In this work, we propose to study the $α$-cluster structures within the framework of valence-space microscopic cluster model (VS-MCM), which is a hybrid between microscopic and macroscopic cluster models and inherits features from both models, making it capable to investigate the $α$-cluster structures in heavy nuclei from a relatively microscopic viewpoint. In VS-MCM, the valence $α$ clusters are described by antisymmetrized microscopic wave functions, with single-particle orbits in core nuclei removed systematically from the model space via the Pauli projection to simulate the antisymmetrization between $α$ clusters and doubly magic cores. As a proof of principle, we apply the VS-MCM to study the $α$-cluster structures in ${}^{20}$Ne and ${}^{44}$Ti at first, with the theoretical energy levels of the $K^π=0_1^{\pm}$ bands for ${}^{20}$Ne and ${}^{44}$Ti showing reasonable agreement with experimental data. These calculations lay the foundation for future applications of VS-MCM in general cluster structures across the nuclide chart, where more $α$ clusters and valence nucleons can exist outside the heavy doubly magic core, opening new avenues to study the $α$ and cluster decays in heavy nuclei microscopically.

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arXiv2024

A Complex Scaling Method for Efficient and Accurate Scattering Emulation in Nuclear Reactions

We present a novel scattering emulator utilizing the complex scaling method to enhance nuclear reaction analysis. This approach leverages a single set of reduced bases, allowing for efficient and simultaneous emulation across multiple channels and potential parameters, significantly reducing computational storage and accelerating calculations. Demonstrated through $n$+$^{40}$Ca and $^{11}$Be+$^{64}$Zn elastic scattering, our method achieves high accuracy and efficiency. This emulator exhibits stable and reliable performance without anomalies inherent in other techniques, showcasing its robustness.

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