Recently the nucleon-nucleon interaction derived using time-ordered perturbation theory in manifestly Lorentz-invariant chiral effective field theory was shown to yield promising results for peripheral neutron-proton scattering. In this work we study low partial waves at next-to-leading order by treating the potential nonperturbatively in the scattering equation. Reasonable description of the phase shifts in the $S$ and $P$ waves as well as the deuteron properties is observed, which can be regarded as a feasibility study for the application of our formalism to the few- and many-body calculations.

We investigate the shell structure of the ${}^{22}\mathrm{Al}$ (hyper)nucleus within the deformed Skyrme-Hartree-Fock approach, precisely reproducing the core binding energies by modifications to the nuclear force parameters. We analyze proton single-particle levels and density distributions and in particular the effect of adding a $\mathrm{\Lambda }$ hyperon in the deformed calculation. The latter might induce important core configuration changes, enhancing a possible proton halo feature.

Background: Cluster radioactivity is a rare decay mode that bridges $\alpha$ decay and spontaneous fission. Despite extensive study, the quantitative role of nuclear structure effects in this process remains unclear.

Purpose: This work aims to investigate the influence of nuclear deformation parameters and their signs on the calculated half-lives of cluster decay. It further explores how quadrupole and higher-order deformations, along with orientation effects, affect cluster preformation probabilities and decay dynamics within the preformed cluster-decay model (PCM). To enhance predictive accuracy and reveal structural correlations, symbolic regression using genetic programming (GPlearn) is applied.

Methods: The cluster-daughter interaction potential is derived from the Skyrme energy density functional using the two-parameter Fermi (2pF) model. PCM calculations explicitly include deformation and orientation degrees of freedom for cluster emissions leading to ${}^{208}\mathrm{Pb}$ and neighboring isotopes. The GPlearn model is trained to establish functional relationships between structural inputs and decay half-lives.

Results: The decay half-lives are primarily calculated using the PCM, which reproduces the available experimental data with remarkable consistency and accuracy, establishing its reliability for predictive purposes. The observed agreement between theory and experiment reflects the strength of the Skyrme-based microscopic framework, where deformation-induced modifications in nuclear densities and interaction terms directly influence the calculated decay half-lives. The analysis demonstrates that higher-order multipole deformations play a crucial role in improving the agreement with experimental half-lives by introducing significant structural corrections. While the quadrupole deformation provides a baseline contribution, the inclusion of higher-order terms substantially modifies the fragmentation potential and barrier penetrability, influencing the relative preformation probabilities of competing decay channels. The study further shows that cold elongated configurations yield half-lives much closer to experimental values compared with cold optimum orientations, emphasizing their role in reducing barrier heights at larger interaction radii. For comparison, the PCM results are also examined alongside various semi-empirical formulas and the GPlearn-based regression technique. Both comparative approaches exhibit a similar overall trend, supporting the robustness of the PCM predictions, especially in regions where experimental data are not yet available.

Conclusion: The PCM successfully captures the recent experimental trends in decay half-lives, particularly when higher-order deformations and orientations are incorporated. These effects significantly refine the calculated results and confirm the model's predictive strength across a wide range of nuclei. The GPlearn-based regression and semi-empirical formulas are employed primarily for comparison, validating the consistency and reliability of the PCM outcomes in both known and unexplored regions. This combined analysis establishes PCM as the principal theoretical framework for predicting cluster decay half-lives, supported by data-driven and semi-empirical approaches for cross-verification.

A measurement of the thermal neutron capture cross section of ${}^{73}\mathrm{As}$ (${\mathrm{t}}_{1/2}=80.3$ d) was performed utilizing the University of Missouri Research Reactor. Two sealed quartz tubes containing ${}^{73}\mathrm{As}$ were prepared and characterized before being irradiated for $\approx 1$ week. The resulting production of ${}^{74}\mathrm{As}$ was quantified with γ-ray spectroscopy. Monitor foils of Fe, Zr, and Mo were irradiated alongside the ${}^{73}\mathrm{As}$ samples to assess the thermal and resonance region neutron fluxes. The thermal ${}^{73}\mathrm{As}(n,\gamma )$ cross section was determined to be $56.1\pm 8.9$ b based on the average of the two ${}^{73}\mathrm{As}$ samples and represents the first neutron-induced reaction cross section measured on ${}^{73}\mathrm{As}$.

Cluster radioactivity has been successfully described as a superasymmetric fission mode within the microscopic self-consistent Gogny Hartree-Fock-Bogoliubov approximation [M. Warda and L. M. Robledo, Phys. Rev. C 84, 044608 (2011)]. For nuclei preserving the neutron-to-proton $N/Z$ ratio of the doubly magic ${}^{208}\mathrm{Pb}$, a cluster radioactivity fission valley has been identified. Such a valley can also be found both in actinides and superheavy nuclei. In this paper, chains of isotopes and isotones are examined to determine the limits of existence of the cluster radioactivity fission mode. It is shown that the superasymmetric valley can be found in a wide range of the nuclear chart. Nevertheless, the valley flattens more and more when diverging from the isospin asymmetry of ${}^{208}\mathrm{Pb}$. For neutron-deficient nuclei with $N/Z<$ 1.41, it is found that the valley diminishes before reaching the scission point, and cluster radioactivity cannot be observed.

The study of heavy-flavored baryon and meson production in proton-proton (pp) collisions provides crucial insight into the hadronization mechanisms of quantum chromodynamics (QCD). In this work an attempt has been made to describe the existing ALICE and LHCb results on the $p_{\mathrm{T}}$-differential production cross section of ${\mathrm{\Lambda }}_c^{+}, D^0, {\mathrm{\Lambda }}_b^0$, and ${\overline{B}}^0$, and $p_{\mathrm{T}}$-dependent ${\mathrm{\Lambda }}_c^{+}/D^0$ and ${\mathrm{\Lambda }}_b^0/{\overline{B}}^0\left(B^0\right)$ ratios, in light of the color-string junction inspired PYTHIA-8.314 model. A comparison of the results obtained with various event samples generated with different tuning parameters and the existing experimental results of ALICE and LHCb at $\sqrt{s}=$ 7 and 13 TeV underlines the relevance of string-junction dynamics in heavy-flavored particle production. The results of the present investigation reveal that while stopping the junction-antijunction reconfiguration in the nonperturbative PYTHIA-8.314 model successfully describes the considered ALICE experimental observables of the charm sector, on the other hand, allowing junction-antijunction reconfiguration, keeping other fragmentation parameters the same, better describes the LHCb experimental observables of both charm and bottom sectors.

We study the evolution of matter composition from nuclear to quark densities in the confining regime by extending an ideal model of quarkyonic matter, the IdylliQ model, to multiflavor systems including strangeness. The model provides a dual description of quark and baryon occupation probabilities which are determined by minimizing the energy of the system. Saturation of low-momentum quark states drives the formation of quark matter and constrains baryon distributions, inducing statistical repulsion among baryon species. Applying the model to charge-neutral matter composed of neutrons, ${\mathrm{\Lambda }}_0$, and ${\mathrm{\Sigma }}_0$ hyperons, we find that, for typical size of baryons, $d$-quark saturation occurs before hyperons appear, delaying their onset and shifting the threshold density from $\sim 2-3n_{\mathrm{sat}}$ to $\sim 5-6n_{\mathrm{sat}}$ ($n_{\mathrm{sat}}\approx 0.16{\mathrm{fm}}^{-3}$: nuclear saturation density). After hyperons emerge, low-momentum hyperon states remain only sparsely occupied due to the quark saturation. These features mitigate the hyperon puzzle, in which the appearance of hyperons softens neutron star equations of state significantly by increasing energy density with little pressure increase. Our results highlight the key role of quark saturation in dense baryonic matter and provide new insights into the interplay between quark dynamics and hyperon physics in neutron stars.

We investigate the contribution of radial excitations to Fermi $\beta$-decay matrix element. To this end, exact no-core shell-model calculations are performed for the mirror $\beta$ decay of tritium, where full convergence can be achieved on an ordinary computer. The differences between the isospin-mixing correction values obtained in the full and in a restricted model spaces are matched to the radial overlap correction term, analogous to that required in the shell-model approach, where the configuration space is extremely limited. We examine this complementary correction term using a nonorthogonal harmonic-oscillator basis, generated by slightly differentiating the oscillator frequencies between the initial and final nuclei, while all desirable properties, including translational invariance, are still preserved. For $N_{\max }\le 8$, we find that the radial excitation contribution is negative, with a typical magnitude of approximately 10% to 20% of the radial diagonal contribution. This effect becomes more pronounced as the model space increases. Therefore, the ${\delta }_{C2}$ values obtained in the shell-model approach, where radial excitations are not explicitly included, are likely overestimated. Based on experimental $ft$ data and the corrective terms adopted in the survey by Hardy and Towner [Phys. Rev. C 102, 045501 (2020)], we show that the incorporation of radial excitations for the superallowed $0^{+}\to 0^{+}$ nuclear $\beta$ decay tends, however, to worsen agreement with the standard model.

We report a high-precision mass measurement of ${}^{61}\mathrm{Zn}$, performed with the ISOLTRAP mass spectrometer at ISOLDE, CERN. Our result agrees with a recent measurement from the LEBIT Penning trap at FRIB and reduces the mass uncertainty by a factor of four. Combined with recent measurements of the mirror nuclide ${}^{61}\mathrm{Ga}$ performed by TITAN at TRIUMF and CSRe at HIRFL, we obtain a more accurate $Q$ value. This new value slightly improves the determination of the corresponding $\mathcal{F}t$ value in the $T_z=1/2$ mirror beta decays used to test the conserved vector current hypothesis in the standard model.

This work presents a combined experimental and theoretical investigation of the ${}^9\mathrm{Be}({}^6\mathrm{Li}, {}^4\mathrm{He}){}^{11}\mathrm{B}$ transfer reaction at an incident energy of 68 MeV. Angular distributions of the emitted ${}^4\mathrm{He}$ particles were measured for several low-lying states of ${}^{11}\mathrm{B}$. The experimental data were analyzed within the coupled reaction channel (CRC) and coupled-channels Born approximation (CCBA) frameworks. Shell-model calculations provided spectroscopic amplitudes necessary for evaluating transfer mechanisms. The results confirm the dominant role of direct deuteron transfer in populating low-lying states. Theoretical predictions agree well with the measured angular distributions. These findings provide new insights into the role of cluster degrees of freedom and proton-neutron correlations in light nuclei.

The formation probability of the compound nucleus $P_{\mathrm{CN}}$, predominated by quasifission, is pivotal for synthesizing heavy and superheavy elements via fusion-evaporation reactions. However, $P_{\mathrm{CN}}$ has thus far been formulated only phenomenologically, with substantial discrepancies observed in certain systems. Therefore, accurate prediction of $P_{\mathrm{CN}}$ is essential when designing heavy-ion fusion experiments. In this study, we quantitatively investigate $P_{\mathrm{CN}}$ using a machine learning (ML) algorithm, eXtreme Gradient Boosting. To reproduce entrance-channel properties as accurately as possible, we introduced various input features, including the charge product, the ratio of center-of-mass energies to the Bass barrier, fissility parameters, mass asymmetry, and static deformation parameters of the compound nucleus. The precision of the ML model was characterized using the mean absolute error (MAE), which is the average absolute difference between log ${}_{10}$ of the predicted and experimental $P_{\mathrm{CN}}$ values. The associated uncertainty was evaluated by repeatedly training on randomly split subsets of the dataset. The trained models achieved mean MAEs of 0.056 and 0.070 for the training and validation sets, respectively. For the test set, the mean MAE was 0.077, and the ratios between the predicted and experimental $P_{\mathrm{CN}}$ values were mostly distributed within a factor of ${10}^{\pm 0.2}$. Furthermore, we compared the predictability of our ML approach with $P_{\mathrm{CN}}$ values calculated using the semiempirical formula proposed by Zagrebaev and Greiner, revealing that our ML model yielded better performance on the test set by aligning closer with the experimental results.

In this work, we investigate the sequential $\alpha$-decay chains of ${}^{219}\mathrm{Np}, {}^{220}\mathrm{Np}, {}^{223}\mathrm{Np}$, and ${}^{224}\mathrm{Np}$ nuclei produced in fusion-evaporation reactions, within the framework of the Dynamical Cluster-decay Model (DCM) using compact configurations. For comparison, the ground-state $\alpha$ decay of the ${}^{227}\mathrm{Np}$ nucleus is analyzed using the Preformed Cluster Model (PCM) with elongated configurations. The sensitivity of $\alpha$-decay half-lives to the nuclear surface diffuseness parameter is examined, revealing contrasting trends in compact and elongated orientations, which impart significant modifications in the corresponding barrier characteristics. Motivated by these observations, an empirical prescription for the diffuseness parameter is proposed, explicitly incorporating isospin asymmetry, mass number, and decay energy. This relation reproduces experimental half-lives at near-touching configurations, yielding a root-mean-square deviation of approximately 0.04 across the studied Np chains. Its predictive strength is further validated in reference to the $\alpha$-decay chain of ${}^{214}\mathrm{U}$, confirming its wider applicability. Overall, the results demonstrate that the proposed diffuseness formulation provides a physically grounded and quantitatively reliable framework for describing sequential $\alpha$-decay dynamics in the heavy and actinide nuclei.

This study investigates the impact of nucleon-nucleon correlations on heavy-ion collisions using the hadronic transport model smash in $\sqrt{s_{NN}}=3$ GeV ${}^{197}\mathrm{Au}+{}^{197}\mathrm{Au}$ collisions. We developed an innovative Monte Carlo sampling method that incorporates both single-nucleon distributions and nucleon-nucleon correlations. By comparing three initial nuclear configurations—a standard Woods-Saxon distribution (un-corr), hard-sphere repulsion (step corr), and ab initio nucleon-nucleon correlations (nn-corr)—we revealed minimal differences in traditional observables except for ultracentral collisions. When distinguishing between un-corr and nn-corr configurations, conventional attention-based point-cloud networks and multievent mixing classifiers failed (accuracy 50%). To resolve this, we developed a novel deep learning architecture integrating multievent statistics and high-dimensional latent space feature correlations, achieving 60% overall classification accuracy, which improved to 70% for central collisions. This method enables the extraction of subtle nuclear structure signals through statistical analysis in high-dimensional latent space, offering a new paradigm for studying initial-state nuclear properties and quark-gluon plasma characteristics in heavy-ion collisions. It overcomes the limitations of traditional single-event analysis in detecting subtle initial-state differences.

The Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy provides a time-reversal-symmetric framework for describing the nonequilibrium evolution of many-body systems. Despite the success of Boltzmann-based numerical approaches, systematically extending beyond this lowest-order truncation to the full nonlinear BBGKY hierarchy remains a major challenge. Moreover, even at the Boltzmann level, accurately treating the nonlinear collision term still presents significant difficulties. Here we propose the spectral BBGKY hierarchy, an analytically equivalent and numerically tractable reformulation of the conventional BBGKY hierarchy. The spectral formulation reduces the original $6n$-dimensional phase-space problem to the evolution of spectral coefficients over the $3n$-dimensional coordinate space, thereby eliminating the need for momentum-space discretization. In addition, we develop an analytic scheme for computing the collision integrals, which achieves high accuracy and removes the need for ensemble averaging over repeated stochastic evolutions from the same initial state. The scheme evaluates the full eight-dimensional integral exactly for massless particles, and reduces it to a three-dimensional one for massive particles. The validity of the spectral BBGKY hierarchy is verified through conservation law analysis, comparison with an analytical solution, convergence tests, and analysis of spectral coefficient leakage. At minimal truncation, the spectral BBGKY yields a spectral nonlinear Boltzmann equation that captures nonlinear dynamics with a computational cost comparable to that of conventional linearized approaches. When extended to higher-order truncations ($n\ge 2$), the spectral BBGKY hierarchy provides a flexible framework for studying multiparticle correlations across a wide range of systems—from ultracold atomic gases and quark-gluon plasma produced in relativistic heavy-ion collisions to the primordial plasma of the early universe. This framework advances our ability to investigate the early thermalization puzzle in relativistic heavy-ion collisions and to elucidate the applicability of hydrodynamics at remarkably early stages of quark-gluon plasma evolution.

It is shown that longitudinally polarized protons can be used to induce chirality in the final states of the $(\vec{p},pN)$ reaction at intermediate energies, when there exist three final-state particles with non-coplanar momentum vectors. The analyzing power $A_z$ is proposed as a measure of this effect. Theoretical descriptions to obtain $A_z$ based on an intuitive picture as well as a distorted wave impulse approximation are presented, showing that the helicity of incident protons is coupled to the chirality of the orbital motion of a single-particle wave function, resulting in the chirality of the final states and a large $A_z$ value.

In the present work, experimental study of incomplete fusion in the ${}^{19}\mathrm{F}+{}^{93}\mathrm{Nb}$ system has been carried out in the energy range of $\approx$ 3–6 MeV/nucleon. The off-line $\gamma$-ray spectrometry was used to measure the cross sections of evaporation residues populated in this system. The analyses of experimentally measured excitation functions have been performed with theoretical predictions from the statistical model code PACE4 to probe the associated reaction mechanism. The imitation of $xn/pxn$ channels data grossly by the statistical model confirms the production of these residues via complete fusion process. However, the noticeable enhancement observation in $\alpha$-channel cross sections hints at the signatures of breakup fusion in addition to the dominant complete fusion. Furthermore, the present study, in light of literature data involving the interaction of ${}^{13}\mathrm{C}, {}^{16}\mathrm{O}$, and ${}^{18}\mathrm{O}$ projectiles with the same target ${}^{93}\mathrm{Nb}$, imparts the reliance of projectile structure on incomplete fusion, and the results may be understood on the basis of the projectile $Q_{\alpha }$ value. An attempt has also been made to discuss the trend of incomplete fusion fraction through the Coulomb factor and total asymmetry of the interacting partners. For the present studied system, the fusion function calculated from the experimentally measured fusion cross section data is compared with the universal fusion function to get information about fusion supression.

Rather than using the geometric method employed in the original extended quantum molecular-dynamics (EQMD) model, this article employs a stochastic approach to analyze the collision term and examine the width of the isovector giant-dipole resonance (GDR) in ${}^{208}\mathrm{Pb}$. Based on the “soft” EQMD model, which we recently developed, the response and strength functions are self-consistently determined for various symmetry energy coefficients and in-medium reduction-factor values. The results confirm that the peak position and GDR width in ${}^{208}\mathrm{Pb}$ are highly sensitive to the symmetry energy and the in-medium nucleon-nucleon ($\mathit{NN}$) cross section. This provides an opportunity to study the nuclear equation of state (EoS) and the medium effect. A significant reduction in free $\mathit{NN}$ elastic cross sections within the medium is necessary to accurately reproduce the GDR width, as demonstrated by a comparison with the evaluation data.

Measurements of semi-inclusive deep-inelastic scattering multiplicities for ${\pi }^{+}$ and ${\pi }^{-}$ from proton and deuteron targets are reported on a grid of hadron kinematic variables $z, P_T$, and ${\varphi }^{*}$ for leptonic kinematic variables in the range $0.3<x<0.6$ and $3<Q^2<5{\mathrm{GeV}}^2$. Data were acquired in 2018 and 2019 at Jefferson Lab Hall C with a 10.6 GeV electron beam impinging on 10-cm-long liquid hydrogen and deuterium targets. Scattered electrons and charged pions were detected in the High Momentum Spectrometer and Super High Momentum Spectrometer, respectively. The multiplicities were fitted for each bin in $(x,Q^2,z,P_t)$ to extract the ${\varphi }^{*}$—independent $M_0$ and the azimuthal modulations $\langle cos\left({\varphi }^{*}\right)\rangle$ and $\langle cos\left(2{\varphi }^{*}\right)\rangle$. The $P_t$ dependence of the $M_0$ results was found to be remarkably consistent for the four cases studied: $ep\to e{\pi }^{+}X, ep\to e{\pi }^{-}X, ed\to e{\pi }^{+}X, ed\to e{\pi }^{-}X$ over the range $0\text{GeV}<P_t<0.4\text{GeV}$, as were the multiplicities evaluated near ${\varphi }^{*}={180}^{\circ }$ over the extended range $0\text{GeV}<P_t<0.7\text{GeV}$. The Gaussian widths of the $P_t$ dependence exhibit a quadratic increase with $z$. The $cos\left({\varphi }^{*}\right)$ modulations were found to be consistent with zero for ${\pi }^{+}$, in agreement with previous world data, while the ${\pi }^{-}$ moments were, in many cases, significantly greater than zero. The $cos\left(2{\varphi }^{*}\right)$ modulations were found to be consistent with zero. The higher statistical precision of this dataset of about 20 000 individual multiplicity values, compared with previously published data, should allow improved determinations of quark transverse momentum distributions and higher twist contributions.