Papers

Transfer and multi-nucleon transfer reactions are essential tools for probing nuclear structure and reaction dynamics, requiring precise determination of the identity, energy, and emission angles of reaction products. The increasing granularity of modern silicon telescope arrays enhances experimental capabilities but challenges detector calibration, as conventional channel-by-channel approaches become inefficient and difficult to scale. In this work, we present a fully automated, physics-informed calibration framework based on neural networks, specifically designed for highly segmented silicon detector arrays. The method formulates calibration as a global optimization problem, in which detector gains and geometrical corrections are determined simultaneously by minimizing the width of the reconstructed excitation energy under two-body kinematics constraints. The approach relies exclusively on experimental data and well-established physical principles, without requiring explicit modeling of detector response. A distinctive feature is the use of multiple neural network sub-models sharing a common loss function with embedded physics constraints, enabling coherent and self-consistent calibration across all detector channels. This strategy ensures scalability, robustness, and reproducibility, making it particularly suitable for next-generation detector systems with increasing complexity. The performance of the method is demonstrated using experimental data from the Particle-Identification Silicon-Telescope Array (PISTA) in high-resolution fission studies in inverse kinematics. The results show excellent agreement with theoretical kinematics, high-quality particle identification, and a significant improvement in calibration efficiency. The proposed framework provides a general and adaptable solution for the calibration of complex detector systems in modern nuclear physics experiments.

Low-energy nuclear structure is encoded in a broad body of experimental information across the chart of nuclides. Learning how this information is organized across observables and nuclei can provide a data-driven empirical baseline for theoretical extrapolations and experimental design. Here, we develop held-out ensembles based on NuCLR (Nuclear Co-Learned Representations), a multi-task model of nuclear data, to study charge radii and electric-quadrupole transition strengths. Out-of-fold (OOF) validation shows that shared representation improves performance over single-task learning, yielding a charge-radius $\mathrm{RMS}$ deviation of $0.0147~{\rm fm}$ and a $\mathrm{B(E2)}$ $\mathrm{RMS}$ deviation of $0.192~e^2{\rm b}^2$ across hundreds of nuclides, competitive with state-of-the-art nuclear models. Our error bars estimate the expected prediction accuracy across the nuclear chart, highlighting regions where new data would encode information beyond the learned patterns. NuCLR thus serves as a data-driven surveyor of nuclear structure and a step toward a shared, multi-observable foundation model of the nuclear chart.

A species-resolved anisotropy-response scaling framework is used to investigate the structure and formation dynamics of the $f_0(980)$ in relativistic nuclear collisions. Published measurements in high-multiplicity p+Pb collisions at $\sqrt{s_{NN}}=8.16$~TeV exhibit broad scaling closure under a single-meson response construction, with a small effective final-state response, $\zeta_{f_0}\simeq0.04$, whereas a symmetric ${\rm K\bar K}$ constituent-response construction gives substantially poorer closure. An explicitly molecular ${\rm K\bar K}$ calculation also exhibits single-meson-like scaling but gives a substantially larger effective final-state response, $\zeta_{f_0}\simeq0.16$. Thus, single-meson scaling alone is not a unique structural discriminator. The combined response construction and $\zeta_{f_0}$ constraints characterize the measured $f_0(980)$ by a single-meson-like anisotropy response with weak final-state sensitivity, distinctly different from the molecular benchmark. These results establish anisotropy-response scaling as a new experimental probe of $f_0(980)$ formation dynamics and motivate systematic tests across collision systems and beam energies.

Recent measurements of two-particle transverse-momentum correlations, $C_{p_T}$, in Au+Au collisions have revealed a statistically significant non-monotonic beam-energy dependence over the range $\sqrt{s_{NN}}=3.0$–$7.7$~GeV that has been interpreted as potentially indicative of critical phenomena associated with a critical end point (CEP) in the QCD phase diagram. This interpretation is assessed in light of the absence of a controlled framework establishing $C_{p_T}$ as a quantitative proxy for the underlying critical response. The implications of this limitation are examined by considering the expected finite-size and finite-time modification of critical fluctuations, substantial non-critical dynamical contributions, the lack of demonstrated critical scaling, and the sizeable discrepancy between the CEP region inferred from the observed $C_{p_T}$ non-monotonicity and that constrained by susceptibility-based measurements and finite-size scaling analyses. Taken together, these considerations indicate that the observed $C_{p_T}$ non-monotonicity does not, by itself, establish a critical origin nor provide reliable quantitative constraints on the existence or location of a possible CEP.

Charge-dependent directed flow provides a sensitive probe of early electromagnetic fields and baryon stopping in relativistic heavy-ion collisions. Recent STAR measurements show a centrality-dependent sign change in the directed flow splitting (the difference between the directed flow of protons and antiprotons), indicating that electromagnetic effects alone are not sufficient to describe this observable and that the baryon stopping $-$ in particular the component of the stopped proton distribution that is odd in rapidity and odd under reflection in the impact parameter direction $-$ must also be included. We develop a semi-analytic hydrodynamic framework that combines spectator-induced electromagnetic fields with a Glauber-based description of baryon stopping, built upon an analytic solution for the background hydrodynamic flow due to Gubser together with the simplifying assumption of a constant electrical conductivity. For Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV, we find that baryon stopping gives a positive contribution to the directed flow splitting that decreases for more peripheral collisions, while electromagnetic fields give a negative contribution that is larger for more peripheral collisions. The competition between these two effects naturally reproduces the observed sign change in Au+Au collisions as a function of centrality, describes the observed rapidity dependence in the $50$–$80\%$ centrality interval, and reproduces trends seen in U+U collisions. Although the simplifying assumptions that we have made regarding the analytic background and constant conductivity limit our ability to make quantitative comparisons, our model provides a transparent explanation of how transported baryon number and spectator-induced electromagnetic fields jointly shape charge-dependent directed flow.

We present new results on the matching relations for gluon transverse momentum dependent parton distribution functions up to one-loop accuracy. At tree-level, employing the spinor formalism, we obtain these relations up to twist 3 accuracy for both T-even and T-odd distributions, including the hadron-mass corrections. At one-loop order, we extend the parton-in-parton approach to include higher-twist operators in the small-$b$ expansion. As a result, we derive for the first time the Wandzura-Wilczek relation for the worm-gear T distributions and establish a systematic method to include mass corrections at one-loop and twist-2 accuracies.

Contributions of parton's orbital motion to the nucleon spin are encoded in the transverse-momentum dependent distributions (TMDs) and generalized parton distributions (GPDs). Currently these distributions are accessed through the lepton-induced processes such as semi-inclusive deep-inelastic scattering (SIDIS) and deeply virtual Compton Scattering (DVCS). The (un)polarized Drell-Yan process with hadron beams provides a unique and complementary probe, enabling critical tests of the universality properties of TMDs and GPDs in the space-like and time-like approaches. This talk reviews recent results of TMDs obtained from the Drell-Yan measurements and discusses future prospects for accessing nucleon GPDs through measurements of the exclusive pion-induced Drell-Yan process at J-PARC.

We present a feasibility study demonstrating how recent advances in quantum-sensing technologies can facilitate stringent comparisons between theoretical predictions and experimental measurements of contact-free transitions in muonic atoms. Such comparisons can probe previously unexplored regions of the parameter space governing spin-independent muon-proton interactions and disentangle the extraction of fundamental constants from searches for physics beyond the Standard Model.

Supernovae are major drivers of cosmic chemical evolution. They synthesize heavy elements and disperse them into the interstellar medium via their explosion shocks. Light elements are converted into heavier ones during both presupernova evolution and the explosive event itself. Supernova explosions generate nucleosynthesis environments rich in neutrons, protons, and neutrinos under unique thermodynamic conditions, which can enable the production of heavy elements beyond iron. Modern numerical simulations are constructing increasingly realistic explosion models of various supernova channels, providing more accurate nucleosynthesis conditions and chemical yields. In tandem with advances in large-scale spectroscopic surveys delivering precise, high-resolution stellar abundance data, as well as isotopic ratios from presolar grains and meteorites, our understanding of the supernova role in cosmic nucleosynthesis is poised to advance significantly. We review recent progress in modeling various supernova channels, with particular emphasis on nucleosynthesis yields derived from state-of-the-art simulations. We examine the roles of Type Ia, core-collapse, electron-capture, and pair-instability supernovae in producing intermediate-mass, iron-peak, trans-iron, and very heavy elements, as well as their characteristic chemical imprints. We also outline major theoretical uncertainties that affect yield predictions. We intend this review to serve as a timely reference for theoretical model development and a practical guide for interpreting observational abundance data.

The EXFOR library is a nearly complete database for experimental radionuclide production cross sections for light charged-particle induced reactions, and retrieval of the experimental cross sections in EXFOR is the first step in determination of the best estimate of the radionuclide production cross section. The EXFOR format was designed with 80-column punched cards as the recording media, but the format is still preferred for compilation and exchange of the nuclear reaction data. The format is suitable for reading and processing by EXFOR compilers, but it is not a good choice for reading by EXFOR users with modern computer languages such as Python. We have recently attempted to lower the barrier for modern software engineers to access the information stored in the EXFOR by developing tools converting an EXFOR file to (1) the HTML format for human reading (X4IVEW), and (2) the CX4 (Compact EXFOR) format for tabulation and plotting (X4TOCX). This article introduces X4VIEW and a preliminary version of X4TOCX with the radionuclide production cross section as an example.

Upon transmission through an unpolarized target initially unpolarized nuclei with spin $S\ge1$ acquire tensor polarization due to spin dichroism effect. For nuclei passing several nuclear lengths in the target, the acquired component $p_{zz}$ can reach substantial values of ~0.2-0.8. The beam obtained in this way can be effectively used to study reactions with tensor-polarized nuclei.

Recent progress in collider physics has reformulated phenomenological questions in terms of detector correlation functions and advanced their theoretical understanding. These advances have primarily focused on correlators of the average null energy operator, $\mathcal{E}(\vec{n})$, known as energy correlators. However, colliders have access to a much broader class of detector operators, $\mathcal{E}^n_R(\vec{n})$, which measure powers of the energy on a subset of hadrons $R$, such as charged hadrons. These generalized detectors are generically not infrared and collinear safe, and their description requires nonperturbative matching between the hadronic detectors measured in the infrared and the partonic detectors used in ultraviolet calculations. We develop a framework for computing their multi-point correlation functions. We introduce universal nonperturbative matching coefficients, termed "detector functions", that implement this infrared-ultraviolet matching. For the $\mathcal{E}_R^n$ operators studied here, these coefficients are represented by energy-weighted moments of single- and multi-hadron fragmentation functions. We present their renormalization group structure, derive QCD factorization theorems for the projected correlators, and compute jet functions through next-to-leading order. In the fixed-coupling pure Yang-Mills limit, we derive the light-ray OPE of hadronic detectors and connect it to the QCD factorization framework. We also identify universal nonperturbative power corrections generated by soft radiation, which are enhanced in the collinear limit and can substantially modify the perturbative angular scaling. A parton shower study finds qualitative agreement with the predicted perturbative and nonperturbative scaling behaviors. Our work significantly broadens the space of detector operators under theoretical control, with potential phenomenological applications.

The neutron skin, defined by the difference between neutron and proton root-mean-square radii, is a characteristic manifestation of isospin asymmetry and an important probe of the isovector nuclear interaction. This focused review examines how neutron skins influence particle emission and collective dynamics in heavy-ion collisions, from the Fermi-energy regime to ultra-relativistic energies. By modifying the initial neutron and proton density profiles, the neutron skin affects the isospin composition and geometry of the participant region, pre-equilibrium emission, particle production, fragment formation, and collective flow. We review neutron-to-proton and $\rm{t}/^3\rm{He}$ yield ratios, light clusters, pion ratios, bremsstrahlung photons, isoscaling and fragment momentum distributions, and neutron-proton differential flow and momentum observables, emphasizing their interplay with the symmetry energy and transport dynamics. At high energies, neutron skins also modify the initial geometry, eccentricities, multiplicities, and anisotropic flows in isobar and heavy-nucleus collisions. We discuss the challenge of disentangling these effects from deformation, surface diffuseness, shell structure, clustering, and model dependence. Broader connections to parity-violating electron scattering, dipole responses, coherent elastic neutrino-nucleus scattering, SRC-induced proton skins in momentum space, and neutron-star observables are also explored. Finally, we highlight opportunities from radioactive beams, improved collision experiments, microscopic many-body and transport calculations, and Bayesian inference. Combining multiple reaction systems and observables with complementary nuclear-structure and astrophysical information will be essential for quantitatively constraining neutron skins and the density dependence of the symmetry energy.

The observed fluid behavior of the matter produced in heavy ion and $pp$ collisions implies that the strings stretched between the constituents of the projectile and target should have a hard core giving rise to a repulsion between them. It is shown that in these collisions there are two critical string densities, one corresponding to the well studied percolation of strings and another to the percolation of the hard core of the strings. These two critical densities are related to two critical temperatures, one T $\sim $ 160 MeV would correspond to the restoration of chiral symmetry and partial deconfinement and a second transition T $\sim $ 220 MeV form the fluid behavior of QCD matter strongly interacting to a quasi free gas of quarks and gluons. This argument is supported by the recently published results on the sudden increase in the degrees of freedom above the deconfinement temperature in pp and A-A collisions.

We analyze the impact of rotation on the chiral crossover transition of QCD matter within the framework of a hadron resonance gas model. By extending the conventional formulation of the renormalized chiral condensate to a rotating hadronic medium, we find that rotation significantly modifies the chiral condensate and systematically suppresses the pseudocritical temperature as the angular velocity increases. The pseudocritical line in the $T-\omega$ plane is examined, and the rotational dependence of the pseudocritical temperature is quantified through leading- and next-to-leading-order rotational curvature coefficients. We further investigate the combined effects of angular velocity and baryon chemical potential and find that their interplay leads to a stronger suppression of the pseudocritical temperature. Additionally, the spatial dependence of the chiral crossover transition is examined through the radial variation of the pseudocritical temperature. We find that the pseudocritical temperature decreases with increasing radial distance, indicating that the chiral crossover sets in at progressively lower temperatures as one goes away from the rotation axis.

The precision of the electromagnetic proton-neutron mass difference $\delta m_\mathrm{QED}$ extracted from the Cottingham formula hinges on a subtraction function whose low-energy normalization $\bar S(0)$ is fixed by the isovector combination of the proton and neutron polarizabilities, $(\alpha_{E1}-\beta_{M1})^{p-n}$. We derive a dispersive sum rule for this combination in terms of $s$-channel photoabsorption cross sections and the product of $t$-channel $\gamma\gamma\to\pi\eta/K\bar K_{I_t=1}$ and $\pi\eta/K\bar K_{I_t=1}\to N\bar N$ amplitudes, without invoking Reggeon dominance. Combining empirical pion-photoproduction multipoles with coupled-channel Muskhelishvili–Omnès representations of the scalar-isovector $\pi\eta/K\bar K$ amplitudes, we obtain $(\alpha_{E1}-\beta_{M1})^{p-n}=-2.26(73)\times10^{-4}\,\mathrm{fm}^3$, fixing its sign and reducing the uncertainty by a factor of 4 compared with the previously known value. This result yields $\bar S(0)=-1.76(61)\,\mathrm{GeV}^{-2}$, leading to $\delta m_\mathrm{QED}=0.71^{+0.03}_{-0.06}\,\mathrm{MeV}$, substantially more precise than previous Cottingham determinations. The negative $\bar S(0)$ also provides a stringent low-energy test of Reggeon dominance in the subtraction function.

We report on our study of inclusive neutral-kaon photoproduction on the deuteron, $d(\gamma,K^0)YN$, for photon energies between 0.9 and 1.1 GeV. The calculation is performed in the impulse approximation, with the deuteron wave function generated from the Bonn One-Boson-Exchange-Potential in $q$-space (OBEPQ) within a non-relativistic framework, while the kinematics and the elementary operator are kept relativistic. For the elementary operator we employ a recently developed isobar model that includes high-spin nucleon and $\Delta$ resonances and has been constrained by nearly 20,000 data points, and we compare its predictions systematically with those of the Kaon-Maid model. For the first time, the NKS1 and NKS2 data are subjected to a quantitative analysis within a modern elementary production framework. The New Operator provides a considerably better description of the data, whereas Kaon-Maid overestimates the measured cross section by up to a factor of four at the higher photon energies, a discrepancy that can be traced back to its unconstrained $\gamma n \to K^0\Lambda$ amplitude. We further show that the finite photon-energy and kaon-angle bins of the existing measurements generate a theoretical uncertainty comparable to the difference between the two models, so that a proper comparison with the data requires the calculation to be averaged over the experimental acceptance. A three-dimensional mapping of the cross section over the kaon momentum and angle reveals a narrow quasi-free ridge, accompanied by a second structure associated with the opening of the $\Sigma$ channels, from which we identify the kinematics most favorable for future measurements. Finally, the tensor target asymmetries are found to be far less sensitive to the elementary operator than the cross section, and therefore probe the nuclear dynamics in a way that is complementary to the cross section.

In many physics and space experiments the direction of a magnetic field must be known to one milliradian or better. We have developed a new type of magnetic compass, based on rotation, in which a spinning Hall probe (HP) produces an alternating signal proportional to the component of the magnetic field transverse to the axis of rotation. Aligning the rotation axis so that this signal vanishes gives the direction of the field. The device requires no calibration and is insensitive to electronics drift. A spinning-HP compass was built and used in a recent experiment at Jefferson Lab, where it determined the direction of the 25~G holding field of a polarized $^3$He target to about 1~mrad; the direction of the rotation axis was transferred to the laboratory frame with a laser and a flat mirror attached to the rotor. A second implementation of the rotation approach, a spinning field concentrator (SFC) with a stationary Hall probe, was also built. With 10 seconds of averaging the SFC compass resolves a transverse field of 18~$\mu$G, corresponding to a directional resolution of 70~$\mu$rad in a field of 0.25 G, close to the Earth's field.

We develop and implement a two-step location-scale analysis for repeated physical measurements when the underlying distribution is not known. For a chosen substitute distribution, stationarity of population Kullback-Leibler information loss at fixed scale motivates the location score, which we apply to the observed measurements through empirical cross-entropy. Steiner's curvature rule then defines a companion scale separately. We place Gaussian, Cauchy, and logistic substitutes in one common construction and implement them reproducibly on a physics benchmark. For the logistic substitute, we pair the established bounded location score with a scale defined by the curvature rule rather than by a fitted tuning constant or a scale-likelihood equation. For Gaussian measurements with different quoted uncertainties, an experiment-level curvature convention and a stated variance mapping give an exact algebraic connection to a standard residual-based variance estimate for a weighted fit. Applied to a published 21-measurement neutron-lifetime compilation, the inverse-variance weighted, most frequent value, and logistic locations are 878.689, 881.164, and 882.835 s, respectively. These values are benchmark results of the compared constructions and are not proposed as a new recommended neutron lifetime.

In relativistic heavy-ion collisions, the linear polarization of quasi-real photons can correlate the spin orientation of photon-induced vector mesons with the collision geometry. To explore this sensitivity, we present the first measurement of the decay angular distribution of photon-induced $J/\psi$ with respect to the event plane in heavy-ion collisions with hadronic overlap. The analysis uses Ru+Ru and Zr+Zr collisions at a nucleon–nucleon center-of-mass energy of $\sqrt{s_{\mathrm{NN}}}=200$ GeV recorded by STAR. After correcting for the finite event-plane resolution and subtracting the residual hadronic contribution, we extract a negative second-order modulation, $A_2^{\rm phot} = -0.39 \pm 0.11~(\mathrm{stat.}) \pm 0.04~(\mathrm{sys.})$, for $|y^{ee}|<0.8$, $p_{\mathrm T}^{ee}<0.2~\mathrm{GeV}/c$, and 30–80% centrality. This modulation provides evidence that the $J/\psi$ polarization is correlated with the event plane, as expected for linearly polarized photons. The observed modulation establishes polarized $J/\psi$ photoproduction as a direct probe of the transverse orientation of the initial collision geometry.

In the LEPS2 facility constructed at SPring-8, hadron photoproduction experiments have been carried out by using a photon beam with high linear polarization in the tagged energy range of 1.3-2.4 GeV. The BGOegg and Solenoid experiments are alternately running with large-acceptance detector setups, which have been prepared by focusing on the measurement of gamma-rays and charged particles, respectively. These two projects have covered a wide range of hadron physics research, including the search for in-medium meson mass modification, the baryon resonance spectroscopy, the studies on exotic hadrons, and so on. This article reviews the physics programs, the obtained results, and the future prospects in the LEPS2 facility.

We present a systematic framework to extract QCD thermodynamic properties at finite baryon density from ultra-central heavy-ion collisions, where the impact parameter is nearly zero and volume fluctuations are strongly suppressed. By mapping the measured multi-particle state of each event to an effective homogeneous fireball through the conservation of total energy, total entropy and net baryon number, a near-thermal state with variations is realized from event to event, which allows thermodynamic response relations to be tested. Using STAR Beam Energy Scan data on charged particle multiplicity and net proton fluctuations, we show that the thermalization condition is satisfied within uncertainties across collision energies, validating the interpretation of ultra-central events as small deviations from a thermally equilibrated state. We then generalize the response relations to finite baryon chemical potential, expressing the response coefficients in terms of the speed of sound and susceptibilities. Our results provide a baseline for using ultra-central collisions to probe the QCD equation of state and phase structure, including the search for the critical endpoint.

This is the second of two papers discussing a new experimental signature of mixed-symmetry states (MSS) in the vibrational nuclei $^{92,94}$Zr and $^{94}$Mo based on proton and neutron transition densities. Quasiparticle-phonon model calculations for these nuclei are extensively tested by comparison to ground-state properties, energies and moments of excited states, transition probabilities between them, and the momentum transfer dependence in $(e,e^\prime)$ and $(p,p^\prime)$ reactions. The overall very good agreement permits the extraction of information on the wave functions of the MSS and their fully symmetric (FSS) counterparts. MSS can be identified by a sign change between the leading proton and neutron two-quasiparticle configurations compared to the FSS. Possible candidates for $2^+$, $3^-$, and $4^+$ MSS are identified. The modification of proton and neutron transition densities, which can be derived from a combined analysis of inelastic electron and proton scattering, by the sign change provide a new experimental signature of MSS. The collectivity of ground-state excitations of predominantly one-phonon FSS and MSS is generated to a large extent by the coupling to high-lying states forming giant resonances with the same spin and parity.

This is the first of two papers discussing a new signature of quadrupole mixed-symmetry states in the vibrational nuclei $^{92,94}$Zr and $^{94}$Mo based on proton and neutron transition densities derived from the comparison of inelastic electron and proton scattering experiments. Results of the $(e,e^\prime)$ and $(p,p^\prime)$ experiments on these nuclei as well as $(p,p^\prime)$ data for other potential cases $^{96}$Mo and $^{70}$Zn are presented. Spin and parity quantum numbers of excited states are assigned based on angular distributions from the proton scattering data in comparison to calculations employing form factors from the collective model in distorted-wave Born approximation. Possible candidates of one-phonon fully symmetric and mixed-symmetry states as well as members of two-phonon multiplets are identified.

The cross sections and resonance structures of $\rm^{75}As$(n,$\gamma$)$\rm^{76}As$ reaction are critical to the neutrinoless double-$\beta$ (0$\nu\beta\beta$) decay searches of $\rm^{76}Ge$, the $s$-process nucleosynthesis of nuclear astrophysics, and Neutron Resonance Capture Analysis for determining the elemental and isotopic composition of archaeological and cultural heritage. We report a high-precision measurement of the $\rm^{75}As$ neutron capture cross sections from 1~eV to 1~MeV, performed at the Back-n facility of the China Spallation Neutron Source using the Time-of-Flight method. In the resolved resonance region, nineteen resonance structures of $\rm^{75}As$(n,$\gamma$)$\rm^{76}As$ reaction have been discovered for the first time, and inconsistencies between evaluated libraries has been resolved. Resonance parameters for the newly observed structures were extracted with the $R$-matrix code SAMMY. These findings will help refine the theoretical predictions of half-lives and decay constants for the double-$\beta$ decay searches of $\rm^{76}Ge$. Astrophysical Maxwellian-averaged cross sections were calculated based on the averaged cross sections in the unresolved resonance region. And the $\rm^{75}As$(n,$\gamma$)$\rm^{76}As$ reaction rates were derived over the astrophysically relevant temperature range in both the main and weak $s$-processes nucleosynthesis. The present reaction rates deviate significantly from the recent theoretical predictions, and the uncertainties are significantly reduced.

We present preliminary results from a measurement campaign conducted with the FIPPS $\gamma$-ray spectrometer at the ILL using an active target made of $^{235}$U dissolved in a liquid scintillator. Prompt $\gamma$ rays were used to extract absolute, independent isotopic fission yields. We obtained yields for a selected set of well-produced even-even nuclei from the $^{235}$U(n$_{\mathrm{th}}$,f) reaction and compared them with JEFF-3.3 evaluated data. This included the doubly magic nucleus $^{132}$Sn, for which we observed a pronounced deficit (about a factor 7) with respect to JEFF-3.3. Using the FIFRELIN fission fragment de-excitation code, we interpreted this discrepancy as evidence that $^{132}$Sn is mainly produced in its ground state at scission or after neutron evaporation. Delayed $\gamma$ rays recorded in the same experiment were also analysed. No deviation was found in the beta decay of $^{132}$Sn compared to the nuclear database. However, an excess of about a 40% was found in the $\beta$ decay of $^{90}$Kr, which may originate from an overestimated ground-state feeding of $^{90}$Rb in the evaluated data.

Background: The generation of spin distributions in fission fragments has attracted substantial interest in recent years and its mechanism is becoming clear alongside the refined description with microscopic theories. In contrast, the microscopic origin of spin distributions in reaction products remain largely unexplored. Methods: Three-dimensional TDHF calculations are performed for multinucleon transfer processes in the $^{40}\text{Ca} + {}^{124}\text{Sn}$ reaction at $E_{\text{c.m.}} \simeq 128.54\,\text{MeV}$ using the Skyrme SLy5 energy density functional. To obtain spin distributions in each transfer channel, the particle-number projection (PNP) and the angular-momentum projection (AMP) are simultaneously achieved for a reaction product. Results: By performing PNP+AMP for TDHF wave functions after collisions, spin-dependent transfer cross sections are calculated for projectile-like fragments (PLFs). From the results, we find that abundant spin distributions can be obtained from the TDHF wave functions. For one-nucleon addition and removal channels, the calculated spin values agree well with those of single-particle states in the $pf$- and $sd$-shell, respectively. Moreover, for a-few-nucleon transfer channels, we show that the obtained spin distributions can be well explained by combinations of total angular momenta of those single-particle states. Furthermore, as the number of transferred nucleons increases, we find that the calculated spin distributions exhibit a smooth singly-peaked shape with a long tail as a function of $J$, which resembles that of empirical spin distributions for thermally equilibrated fragments. An exploratory calculation for induced fission of $^{240}$Pu is also carried out, obtaining similar results as in multinucleon transfer reactions. (shorted due to the arXiv's word limit)

A newly developed, highly-integrated multi-channel front-end readout system – FEAM-256 – is presented for use with position-sensitive gaseous detectors, including parallel-plate avalanche counters (PPACs) and multi-wire drift chambers (MWDCs). The system's position resolution was characterized using both an $\alpha$ source and cosmic-ray muons. Intrinsic position resolutions of 320 $\mu$m for the PPAC, and 424 $\mu$m for the MWDC were achieved. Designed specifically for integration into the data-acquisition infrastructure at the High-Rigidity radioactive Ion Beam Line (HIRIBL) of China's High Intensity heavy-ion Accelerator Facility (HIAF), FEAM-256 enables seamless incorporation of PPAC and MWDC detectors into the HIRIBL experimental setup.

Quantum machine learning has the potential to become a new tool for understanding complex nuclear structures. In this work, we apply a hybrid quantum convolutional neural network (QCNN) to nuclear charge-radius prediction for the first time, aiming to explore the feasibility of quantum machine learning in nuclear-physics data analysis. Based on a classical convolutional neural network (CNN) framework, a small variational quantum convolutional filter is introduced as a quantum feature map to extract local correlations on the nuclear chart. The QCNN shows promising predictive accuracy and training stability, and provides a reliable description of the charge-radius evolution along several representative isotopic chains. These results support further investigation of quantum convolutional architectures for nuclear-structure data analysis.

We investigate the twist-2 and twist-3 tensor-polarized partonic structures of the spin-1 deuteron. Using the operator product expansion with local operators, we derive a Wandzura-Wilczek (WW)-like twist-2 relation between the tensor-polarized twist-2 quark distribution $f_{1LL}$ and the twist-3 distribution $f_{LT}$, together with a Burkhardt-Cottingham (BC)-like sum rule. The local-operator formalism makes the Lorentz structure and rotational invariance manifest and provides useful constraints on the twist-3 sector. We then use a phenomenological parametrization of the twist-2 distribution $f_{1LL}(x)$, constrained by HERMES data on the deuteron structure function $b_1$ at $Q^2=2.5~\text{GeV}^2$, to quantitatively estimate the twist-3 distribution $f_{LT}(x)$ within the WW approximation. The resulting $f_{LT}(x)$ has a shape and magnitude comparable to those of $f_{1LL}(x)$, indicating that subleading-twist effects may be relevant for future experiments at relatively low $Q^2$. In this contribution, we summarize the theoretical derivation of the WW-like relation and BC-like sum rule and present a phenomenological estimate of the tensor-polarized twist-3 quark distribution $f_{LT}$ in the deuteron.