In this paper we present a detailed impact study of semi-inclusive deep inelastic scattering unpolarized cross section measurements using the proposed SoLID apparatus at Jefferson Lab. This type of data, collected at large Bjorken $x_{bj}$, moderate values of $Q^2$, and small values of the transverse momentum of produced hadrons, $P_{hT}$, allows the study of transverse momentum dependent (TMD) parton distribution and fragmentation functions in a still poorly explored region. We present the projected results for charged light mesons based on simulated data. For the azimuthal-angle integrated cross sections we adopt the TMD framework up to the next-to-next-to-next-to-leading-logarithmic $\left({\mathrm{N}}^3\mathrm{LL}\right)$ accuracy, while a simpler TMD parton model is employed for the study of azimuthal angular dependencies.

This study explores the sensitivity of the equation of state (EoS) of dense asymmetric nuclear matter on the nuclear matter incompressibility $K$ and assesses the corresponding effects on the structural properties of neutron stars. To isolate the effect of $K$, we employ six relativistic mean-field parameter sets in which $K$ is systematically varied over the range 200–300 MeV, while the slope of symmetry energy is constrained to a fixed value, ensuring that the observed variations arise primarily from incompressibility. The resulting parameter sets are calibrated to reproduce ground-state properties of finite nuclei and bulk properties of symmetric nuclear matter. The corresponding EoSs for $\beta$-stable matter are then employed to evaluate several neutron-star properties. We find that $K$ affects the stiffness of the EoS at suprasaturation densities, primarily through modifications in higher-order density derivatives such as the skewness parameter $Q_0$. Larger values of $K$ lead to a stiffer EoS, resulting in systematically larger radii and tidal deformabilities, while the maximum mass shows comparatively weaker sensitivity. The radius $R_{1.4}$ of a canonical $1.4M_{\odot }$ neutron star and its associated dimensionless tidal deformability ${\mathrm{\Lambda }}_{1.4}$ respond sensitively to changes in the incompressibility parameter. The neutron-star properties lie in the ranges $M_{max}\approx 2.01M_{\odot }\text{–}2.18M_{\odot }, R_{1.4}\approx 12.88\text{–}13.30\mathrm{km}$, and ${\mathrm{\Lambda }}_{1.4}\approx 550.01\text{–}695.62$, consistent with observational constraints from NICER measurements and gravitational-wave events such as GW170817 and GW190814. The softer EoSs corresponding to lower $K$ values show better agreement with recent bounds on tidal deformability. The present study demonstrates that nuclear incompressibility plays an important role in governing the high-density behavior of the EoS and the structural properties of neutron stars, providing a clearer connection between terrestrial nuclear matter constraints and astrophysical observations of compact stars.

The neutron-deficient neptunium isotopes ${}^{219,220}\mathrm{Np}$ were reinvestigated via the fusion-evaporation reaction ${}^{169}\mathrm{Tm}$(${}^{54}\mathrm{Cr}$, $3\text{−}4n$)${}^{219,220}\mathrm{Np}$ at the gas-filled recoil separator SHANS2 (Spectrometer for Heavy Atoms and Nuclear Structure-2). The $\alpha$-decay properties for these Np isotopes, which are the heaviest $N=126\mathrm{and}127$ isotones known to date, were measured with more statistics and improved precision. The ground-state $\alpha$ decay of ${}^{220}\mathrm{Np}_{127}$ with the $\alpha$-particle energy of $E_{\alpha }=10078\left(16\right)$ keV and the half-life of $T_{1/2}={23}_{-5}^{+9} \mu \mathrm{s}$ was updated. In the case of ${}^{219}\mathrm{Np}_{126}$, the improved decay data with $E_{\alpha }$ = 9015(16) keV and $T_{1/2}$ = $0.{14}_{-0.03}^{+0.07}$ ms were determined. In the framework of the Rasmussen method, the systematics of $\alpha$-decay reduced width match well with the previously known tendency with $N=126$. However, the new data may imply a difference in the influence of the $N=126$ shell effects beyond $Z=92$. In addition, the cross sections of the reaction were measured at several beam energies at the level of picobarns, exhibiting the promising capability of the SHANS2 separator to explore the boundary of the nuclear chart in the most neutron-deficient actinide region.

This study examines the $\alpha$-decay properties of superheavy nuclei with proton numbers $82\le Z\le 126$ within the frameworks of deformed density functional theory and self-consistent Hartree-Fock-Bogoliubov calculations. The research employs the SkM* and SLy4 Skyrme interactions, which are parameterized for closed-shell nuclei up to the magic number 126 and have been extensively utilized for the $\alpha$-emitter nuclei in the superheavy region. Additionally, this research introduces a new set of effective Skyrme parameters, called OMGA*, which incorporates the subsequent neutron magic number $N=184$ to become more effective for the neutron-rich and $\alpha$-emitter nuclei. In addition, this approach seeks to improve descriptions of infinite nuclear matter and the nuclear properties of finite nuclei relevant to alpha emitters in the superheavy region. The calculations are conducted by employing an evolutionary algorithm to perform least-squares fitting of Skyrme parameters to accurately reproduce the corresponding experimental data. The resulting nuclear properties of the stable magic closed-shell nuclei, superheavy nuclei, and further $\alpha$-decay half-lives were systematically compared to experimental data and other theoretical models through self-consistent calculations based on the SkM*, SLy4, and OMGA* Skyrme interactions. The results indicated that the OMGA* Skyrme interaction yielded more realistic $\alpha -$decay properties, binding energies, and root-mean-square charge radii, demonstrating better consistency with experimental data and other theoretical models.

A high-precision experiment in search of the predicted Efimov state in ${}^{12}\mathrm{C}$ at 7.458 MeV excitation energy was performed. Using a state-of-the-art detector system and novel analysis techniques, it was possible to isolate potential Efimov state events at the predicted energy level above the $3\alpha$ threshold with much better sensitivity in the ${}^{12}\mathrm{C}$ excitation energy spectrum compared to the existing data. The mutual ${}^8\mathrm{Be}$ resonance (91.84 keV) condition filters out a total of 21 probable Efimov state events around 7.458 MeV. With $2\sigma$ confidence, it gives an upper limit of $0.014\%$ for the Efimov state $\alpha$-decay branching ratio, which is about an order of magnitude smaller than the latest upper limit found in the literature. This observation was supported by a new penetrability calculation assuming a relatively extended structure for the Efimov state compared to the Hoyle state. However, the triple-$\alpha$ reaction rate, including both the Hoyle state and the Efimov state, was found to be much larger than the allowed limit, strongly suggesting that the Efimov-like state may not exist in ${}^{12}\mathrm{C}$.

This study constrains the range of in-medium mass modification through a comparison of theoretical calculations with experimental transverse momentum spectra and the yield ratio $\overline{p}/p$ of protons and antiprotons. Based on the constrained range and a Gaussian source model with radial flow, the theoretical predictions for the fermion back-to-back correlation (fBBC) of $p\overline{p}$ pairs at BNL Relativistic Heavy Ion Collider energies are presented. The results reveal a strong sensitivity of the fBBC signal to the assumed source time distribution: a Lorentzian form generates a pronounced high-momentum signal, whereas an $\alpha$-stable Lévy form leads to a marked low-momentum signal. Moreover, the in-medium mass modification is shown to enhance the yield ratio $\overline{p}/p$. Therefore, events characterized by a larger $\overline{p}/p$ ratio are predicted to have a significantly higher probability of exhibiting a detectable fBBC signal. This study may propose a promising new direction for the experimental observation of this phenomenon.

We compute radiative corrections to the superallowed $\beta$ decay of ${}^{10}\mathrm{C}$ in an effective field theory approach using nuclear matrix elements obtained from quantum Monte Carlo calculations. These corrections are an important ingredient in the extraction of the Cabibbo-Kobayashi-Masakawa quark mixing matrix element $V_{ud}$, and the role of this work is to illuminate the uncertainties arising from nuclear structure. Our results provide good agreement with both the traditional extraction of $V_{ud}$, as well as with a more recent evaluation performed using the no-core shell model and a dispersion formalism. The dominant uncertainty in this approach is the presence of two unknown low-energy constants that enter into the relevant nuclear matrix elements. Future determinations of these low-energy constants—either from QCD or modeling them with two nucleon amplitudes—would improve the precision of the extraction in this formalism.

In the present work, we focus on reactions around ${}^{85}\mathrm{Rb}$, relevant to the astrophysical $\gamma$ process, where reaction flow is defined by the competition between two channels, the $(\gamma ,n)$ and the $(\gamma ,p)$. The $(\gamma ,p)$ channel was constrained in a previous measurement of the ${}^{84}\mathrm{Kr}(p,\gamma ){}^{85}\mathrm{Rb}$ reaction at Michigan State University using the Summing NaI(Tl)(SuN) detector. Here we present a reanalysis of the same data in which we provide new values for the reaction cross section, and in addition, we use the $\gamma$-ray spectra to constrain the statistical properties of ${}^{85}\mathrm{Rb}$, namely the nuclear level density (NLD) and the $\gamma$-ray strength function ($\gamma \mathrm{SF}$). Using these experimental inputs, we were able to provide a more stringent constraint on the ${}^{85}\mathrm{Rb}(\gamma ,n){}^{84}\mathrm{Rb}$ reaction channel. In addition, the proton optical model potential (pOMP) parameters were modified to obtain a better fit on the experimental data of $(p,\gamma ), (p,n)$, and $(p,2n)$ reaction channels. The constrained NLD and $\gamma \mathrm{SF}$, as well as the modified pOMP, were used to calculate the astrophysical reaction rates for the ${}^{85}\mathrm{Rb}(\gamma ,p){}^{84}\mathrm{Kr}$ and ${}^{85}\mathrm{Rb}(\gamma ,n){}^{84}\mathrm{Rb}$ channels. Based on our results, we conclude that the $(\gamma ,n)$ channel dominates at temperatures relevant for the production of the light $p$ nuclei.

Improvement of the accuracy of neutronics simulation of actual or future reactor designs is essential and requires a better knowledge of the core neutron population. The reactor neutron population is partially driven by $(n,xn)$ reactions that change the number and decrease the energy of the neutrons. However, the cross sections of these reactions are currently not measured with sufficient precision. This is particularly the case for the neutron inelastic-scattering cross section of ${}^{238}\mathrm{U}$, which represents around 90%–95% of the mass of fuel in present and many future reactor core designs. It therefore features on the High Priority Request List for measurement improvement. This cross section can be measured using prompt $\gamma$-ray spectroscopy coupled to neutron time-of-flight measurements, where the total $(n,n^{\prime })$ cross section can be deduced from a combination of the measured $(n,n^{\prime }\gamma )$ partial cross sections and the level scheme information. The knowledge of the ${}^{238}\mathrm{U}$ level scheme is still very incomplete, inducing significant uncertainties on the resulting inelastic-scattering cross section. Therefore, an effort has recently been carried out to experimentally revisit the ${}^{238}\mathrm{U}$ decay scheme by performing high-resolution coincidence spectroscopy of the ${}^{238}\mathrm{U}(n,n^{\prime })$ reaction. To obtain detailed level scheme information, the $\nu$-Ball $\gamma$ spectrometer was coupled to the LICORNE directional neutron source of the ALTO facility, allowing the study of inelastic scattering of fast neutrons (0.5–3 MeV) on ${}^{238}\mathrm{U}$ via $\gamma \text{−}\gamma$ coincidence spectroscopy. Coincidence matrices obtained during the first and the second $\nu$-Ball campaigns were analyzed using the RadWare ESCL8R software. 110 $\gamma$ transitions and 60 levels registered in the Evaluated Nuclear Structure Data File database have been confirmed, and 158 new $\gamma$ transitions and 58 new levels have been found. Although not exhaustive, the ${}^{238}\mathrm{U}$ level scheme information has been significantly improved, and its completeness has been estimated to be up to 1.7214 MeV compared with 1.27854 MeV at present. It is hence expected to decrease the uncertainties of ${}^{238}\mathrm{U} (n,n^{\prime })$ cross sections, which is needed for accurate reactor core modeling.

High-spin structures of holmium ($Z=67$) and erbium ($Z=68$) isotopes are presented near mass 160, a region where collective and single-particle modes of excitation compete in the generation of angular momentum at the highest experimentally attainable spins in atomic nuclei. The level schemes of the ${}^{156,157,158}\mathrm{Ho}$ isotopes have been significantly extended, reaching spins in the $40\hslash$ to $55\hslash$ range, through multiple experiments utilizing the Gammasphere spectrometer. In particular, several new noncollective band-terminating states are reported for these nuclei. The nature of these states, including both valence-space terminations and core-excited oblateconfigurations, is discussed in terms of proton particle-hole (p-h) excitations across the semimagic $Z=64$ shell closure. Cranked-Nilsson–Strutinsky (CNS) calculations have been used to interpret the nature of these noncollective states. The corresponding terminating states in ${}^{154–159}\mathrm{Er}$ are also included, providing a systematic description of band termination in this mass region. In addition, three weak rotational structures have been assigned to ${}^{157}\mathrm{Ho}$ at the highest spins. These collective bands are proposed to be based on a triaxial strongly deformed nuclear shape, involving neutron p-h excitations across the $N=82$ shell gap.

Conventionally, octupole deformation in nuclei has been attributed to strong $\mathrm{\Delta }l=3$ couplings between opposite-parity single-particle orbitals. In this work, we demonstrate that the often-overlooked $\mathrm{\Delta }l=1$ mode also plays an important role. Taking orbitals near the octupole magic number $N=134$ as a benchmark, we systematically evaluate the $\mathrm{\Delta }l=1$ and $\mathrm{\Delta }l=3$ mixing ratios of the wave functions within the Nilsson model. We introduce component-resolved single-particle octupole energy contributions, based on the Hellmann-Feynman relation, to quantify the contributions of each $(\mathrm{\Delta }l,\mathrm{\Delta }j)$ coupling. Furthermore, the impact of $\mathrm{\Delta }l=1$ coupling on the rotational structure is demonstrated via particle-rotor model calculations for ${}^{221}\mathrm{Ra}$ and ${}^{223}\mathrm{Th}$. Our work suggests that $\mathrm{\Delta }l=1$ and $\mathrm{\Delta }l=3$ octupole couplings act synergistically in driving reflection asymmetry, necessitating a revised paradigm for understanding octupole correlation.

The isospin properties and the collectivity of the pygmy dipole resonance (PDR) are longstanding open questions in nuclear structure studies. To answer these questions, the $\gamma$ decay of PDR states in ${}^{208}\mathrm{Pb}$ to the low-lying $2_1^{+}$ state is investigated using the Skyrme particle-vibration coupling model. It is found that the $E1 \gamma$ decay from the PDR states to the low-lying $2_1^{+}$ state is strongly suppressed compared to that from the isovector giant dipole resonance (IVGDR), which reveals the predominantly isoscalar character of PDR. A detailed decomposition of the decay diagrams of the amplitudes of the processes contributing to the decay demonstrates the non-negligible presence of the one-particl–one-hole configurations coupled to the $2_1^{+}$ phonon in the PDR wave function. Furthermore, we give a quantitative way to identify the components of complex-configurations in the wave function, and it is found that such component in PDR is smaller than that in IVGDR and much smaller than that in isoscalar giant quadrupole resonance (ISGQR). However, by analyzing the $E2 \gamma$ decay of the PDR and IVGDR to the $3_1^{-}$ state, we find that the $3_1^{-}$ phonon component is larger in the PDR wave function than in the IVGDR.

The solution of large-scale eigenvalue problems is crucial in nuclear many-body theory, where Hamiltonian matrices often reach extremely large dimensions. Quantum computing opens new perspectives for addressing such demanding problems. Although the quantum phase estimation algorithm offers, in principle, a systematic route to matrix diagonalization, its practical deployment demands levels of coherence and error correction that current quantum hardware cannot yet support. A viable near-term strategy is instead to exploit quantum annealing, which enables the recasting of eigenvalue problems into quadratic unconstrained binary optimization formulations that can be addressed by existing annealing-based processors. Here, we propose a hybrid quantum-classical algorithm that combines quantum annealing and classical deflation to iteratively extract the full eigenspectrum of both standard and generalized eigenvalue problems. We benchmark this method on eigenvalue problems arising from the equation-of-motion phonon method performing calculations on real quantum hardware. Our approach illustrates the capabilities and limitations of near-term quantum devices in addressing nuclear eigenvalue problems.

We present a physics-embedded Bayesian neural-network (PE-BNN) framework that integrates fission product yields (FPYs) with prior nuclear physics knowledge to predict energy-dependent FPY data with fine structure. By incorporating a phenomenological shell-related input feature with an excitation-energy damping term, the PE-BNN captures both fine structures and global energy trends. The combination of this physics-informed input with hyperparameter optimization via the Watanabe-Akaike Information Criterion (WAIC) significantly enhances predictive performance. Our results show that the PE-BNN framework is well suited to observables whose systematic features can be encoded as model inputs, and that it remains consistent with known shell-related trends and independently measured prompt-neutron systematics.

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 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.

Values of the quenching factor $Q$ and respectively specified Landau-Migdal parameter $g^{\prime }$ are deduced from a detailed comparison of experimental and theoretical Gamow-Teller strength distributions in the ${}^{48}\mathrm{Ca}, {}^{90}\mathrm{Zr}, {}^{132}\mathrm{Sn}$, and ${}^{208}\mathrm{Pb}$ parent nuclei. The theoretical distributions are obtained within the simply modified basic version of semimicroscopic particle-hole dispersive optical model, which has been successfully used for describing high-energy particle-hole-type charge-exchange spin-monopole excitations in mentioned parent nuclei. The deduced values are compared with those obtained in other studies. Values of adjusted “spreading” parameters of the model are also deduced from the above-mentioned comparison.

The earliest phase of an ultrarelativistic heavy ion collision can be described as a highly populated system of gluons called glasma. We study some glasma characteristics related to the system's angular momentum. The first one is the global angular momentum perpendicular to the reaction plane, which is spanned by the beam axis and impact parameter vector. We show that only a small fraction of the enormous initial angular momentum of the colliding ultrarelativistic nuclei is transferred to the glasma. Our main focus is the glasma angular momentum directed along the beam axis. This quantity has a local character and results from the inhomogeneous velocity field generated in the glasma. We calculate the vorticity and local angular momentum which show noticeably different behavior. The results are analyzed in detail and discussed in the context of existing experimental data. We argue that neither vorticity nor thermal vorticity but instead the local angular momentum controls the polarization of final-state hadrons.

We present a data-driven deep learning framework for predicting multiple bulk observables in $\mathrm{Au}+\mathrm{Au}$ collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC). A single neural network is trained exclusively on experimental measurements of charged-particle pseudorapidity density distributions, transverse momentum spectra, and elliptic flow coefficients over a broad range of collision energies and centralities, without using simulation outputs as training targets. The network architecture is inspired by the stages of a heavy-ion collision, from the quark-gluon plasma to chemical and kinetic freeze-out, and employs locally connected hidden layers and a structured input design that encodes basic geometric and kinematic features of the system. We demonstrate that these physics-motivated choices significantly improve test performance compared to purely fully connected baselines. The trained model is then used to predict the above observables at energies available at the RHIC, and the results are further cross-checked against the energy dependence of the total charged-particle multiplicity per participant pair, as well as against a CLVisc hydrodynamic calculation with ${\mathrm{T}}_{\mathrm{R}}{\mathrm{ENT}}_{\mathrm{o}}$ initial conditions. Our findings indicate that such physics-guided neural networks can provide useful data-driven interpolation tools for RHIC observables in regions not currently covered by the available measurements and can support further phenomenological studies.