We improve the Geiger-Nuttall framework for $\alpha$ decay by incorporating neutron-proton double-shell and valence-nucleon corrections as the main structural effects through phenomenological correction terms. The role of a second-order energy-dependent term derived from the expansion of the barrier penetration factor is also examined. Based on global fits to experimental $\alpha$-decay data for even-even, odd-$A$, and odd-odd nuclei, the results show that the inclusion of proton shell effect, in addition to the conventional neutron-shell correction, leads to systematic improvements in the description of $\alpha$-decay half-lives. A modified shell criterion considering unpaired valence nucleons further enhances the agreement, particularly for odd-$A$ and odd-odd nuclei, indicating the importance of pairing blocking and single-particle effects. The fitted shell-correction coefficients further reveal that neutron shell effect provides a more robust and global contribution, while proton shell effect is more sensitive to local nuclear structure. In contrast, the second-order correction yields only a marginal improvement and provides a comparatively small additional contribution once valence-nucleon effects are properly included. These results demonstrate that the main improvements in $\alpha$-decay systematics arise from nuclear structure effects, while higher-order tunneling corrections play a relatively small role. The present formulation provides a concise and physically transparent framework for improving empirical predictions of $\alpha$-decay half-lives, with potential applications to heavy and superheavy nuclei.

${}^{117m}\mathrm{Sn}$ and ${}^{119}\mathrm{Sb}$, the latter of which is produced via a ${}^{119m}\mathrm{Te}$ generator, are promising radionuclides for the targeted treatment of both osteoarthritis and small mass tumors via Auger therapy. Experiments were conducted at Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, and Brookhaven National Laboratory to measure the ${}^{\mathrm{nat}}\mathrm{Sb}(\mathrm{p},\mathrm{x}){}^{117m}\mathrm{Sn}$ and ${}^{\mathrm{nat}}\mathrm{Sb}(\mathrm{p},\mathrm{x}){}^{119m}\mathrm{Te}$ cross sections for incident proton energies up to 200 MeV. Additional measurements for coproduced isotopes are included as well. In addition to this dataset, this paper investigates improvements for proton-induced reaction modeling capabilities through comparison of these experimental dataset against theoretical models in TALYS 1.95. Parameter adjustments affecting level density, optical model potential, and preequilibrium emission were explored, with a goodness-of-fit metric established by the largest independent cross-section channels and cross-validated with remaining channels.

Background: A handful of neutron-deficient stable nuclei, known as the “p nuclei,” cannot be produced through astrophysical neutron capture processes. Instead, some of these nuclei are proposed to be produced by $\gamma$-induced reactions on existing r- and s-process seeds. The specific astrophysical site or sites are not yet identified, however, with uncertainties in the cross sections of these $\gamma$-induced reactions playing a role. Databases of reaction rates for astrophysical simulations often rely on theoretical statistical model calculations, such as Hauser-Feshbach, for rates where no experimental information is known. However, reasonable variations in the choice of parametrizations of various nuclear properties can create order-of-magnitude variations in the final predicted cross sections and reaction rates, which are then propagated through the models to the predicted final abundances.

Purpose: To better constrain these statistical model calculations and ultimately reduce the uncertainties from the nuclear physics on our understanding of the p nuclei, a measurement of the cross sections of $\gamma$-induced reactions on the p-nucleus ${}^{102}\mathrm{Pd}$ was undertaken. This work represents the first measurement of its kind, using segmented silicon detectors to measure prompt charged particle emission from $\gamma$-induced reactions.

Methods: Quasimonoenergetic gamma beams from the High Intensity $\gamma$ Source facility bombarded an enriched ${}^{102}\mathrm{Pd}$ target. A segmented silicon array was arranged to detect the particles emitted from $(\gamma ,p)$ and $(\gamma ,\alpha )$ reactions.

Results: Reaction cross sections were deduced at multiple $\gamma$-beam energies between 10 and 19 MeV, and compared to statistical model calculations using talys-1.96. The ${}^{102}\mathrm{Pd}(\gamma ,p){}^{101}\mathrm{Rh}$ reaction cross section was reasonably well reproduced by a subset of photon strength functions and level densities, though the strength to the ground state of ${}^{101}\mathrm{Rh}$ was underestimated at higher incident gamma energies. The ${}^{102}\mathrm{Pd}(\gamma ,\alpha ){}^{98}\mathrm{Ru}$ was in general overpredicted by the various alpha-nucleus optical model potentials.

Conclusions: While the theoretical cross sections used to model the $(\gamma ,p)$ reactions for the p process may be reasonable, a more careful approach is needed in the case of $(\gamma ,\alpha )$. Further work to probe gamma-induced reaction cross sections at and near the p nuclei is warranted.

Impacts of octupole correlations on low-energy excited $0^{+}$ states and two-neutron transfer intensities in Ra and Th isotopes are analyzed within the interacting boson model, using the Hamiltonian parameters that are obtained from microscopic nuclear density functional theory calculations. Incorporating the octupole degree of freedom in the model is shown to give an overall reasonable description of the ground-state-band energy levels and to lower the $0_2^{+}$ ones significantly. The calculation yields a number of excited $0^{+}$ states, most of which are formed by the configurations of more than one octupole boson. Octupole correlations make significant contributions to the $0_1^{+}\to 0_2^{+}(p,t)$ and $(t,p)$ transfer intensities in those nuclei in which the octupole collectivity is most enhanced. Behaviors of the predicted transfer intensities with the increasing neutron number along the isotopic chain reflect nuclear structural evolution.

The ground-state properties of holmium isotopes ($N=74–186$) are systematically studied using the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc). Significant deformation is found across the isotopic chain. Compared to the spherical relativistic continuum Hartree-Bogoliubov (RCHB) approach, the DRHBc theory substantially improves the description of binding energies and neutron separation energies. Abrupt shape transitions between prolate and oblate deformations occur between some neighboring isotopes, arising from two nearly degenerate local minima on the potential-energy curves. Triaxial deformation-constrained calculations reveal a soft potential-energy surface along the $\gamma$ direction, connecting the prolate and oblate shapes for these abrupt shape-transition nuclei. The asymmetric splitting of high-angular-momentum orbitals on prolate and oblate sides may drive the configuration competition, leading to the soft potential-energy surface and resulting in shape transitions.

We investigate the $\beta$-decay properties of $rp$-process waiting-point nuclei ${}^{72}\mathrm{Kr}, {}^{68}\mathrm{Se}$, and ${}^{64}\mathrm{Ge}$ from realistic nuclear forces based on chiral effective field theory. The ab initio valence-space in-medium similarity renormalization group method is employed for this purpose to consistently derive Hamiltonians and Gamow-Teller operators from chiral two- and three-nucleon interactions. The calculated half-lives and branching ratios indicate that nearly the entire decay intensity is confined within 1 MeV of excitation energy in the daughter nuclei. We address the isoscalar and isovector pairing and their impact on ground state properties of these waiting-point nuclei, along with several other $N=Z$ systems in the $fp$ shell. Our results do not provide evidence for an isoscalar condensate or any dominant isovector pairing condensate-like phase in these $N=Z$ nuclei. We present the full $B\left(\mathrm{GT}\right)$ strength distributions and discuss the influence of pairing correlations on them. The present work provides a microscopic picture of $\beta$-decay strengths and pairing in $N=Z$ nuclei far from the stability line.

Photodisintegration reactions play a crucial role in both fundamental physics and applied physics. The ${}^{13}\mathrm{C}(p,\gamma ){}^{14}\mathrm{N}$ reaction provides a potential quasimonoenergetic $\gamma$-ray source with an energy of 9.17 MeV, offering a promising avenue for studying the data discrepancy in photodisintegration reactions. The yield of 9.17 MeV $\gamma$ rays is intrinsically related to the width of the 9.17 MeV level in the compound nucleus ${}^{14}\mathrm{N}$ formed during the reaction. However, previous measurements of the width of this level have shown significant discrepancies, amounting to differences of up to a factor of 1.5. In the present study, we utilized a modern high-resolution $\gamma$ ray detection system and employed the resonance absorption method to obtain a more accurate determination of the width. Our results indicate that the total width of the 9.17 MeV energy level in ${}^{14}\mathrm{N}$ is $\mathrm{\Gamma }={81}_{-14}^{+8}\mathrm{eV}$, which is consistent with the results in 1959 but deviates from those reported in 1989. Our results help resolve the large discrepancies in the resonance width, and this improvement will further advance photonuclear studies and enhance nuclear reaction databases. Shell-model calculations were performed to understand the width difference between the two isospin $T=1 2^{+}$ states at 9.17 and 10.43 MeV.

The ${}^{252}\mathrm{Cf}$ spontaneous fission (sf), prompt fission neutron spectrum (PFNS) is a fundamental quantity for nuclear physics measurements of neutron-emitting reactions. This energy distribution of neutrons emitted from fission has been considered a neutron data standard for decades and has been utilized as a reference for neutron detection efficiency, validation of Monte Carlo simulations, benchmarking of dosimetry standards, and more. A significant portion of the global collection of nuclear data on neutron-induced reactions is correlated with the ${}^{252}\mathrm{Cf}\left(\mathrm{sf}\right)$ PFNS. Despite the reliance on this quantity by the nuclear physics community, the historical collection of ${}^{252}\mathrm{Cf}$ PFNS measurements display systematic disagreements that are not understood or easily explained. These experimental discrepancies could potentially bias the ${}^{252}\mathrm{Cf}$ PFNS Standard evaluation. On top of this, these past experiments frequently employed correlated experimental measurement or analysis methods. The artificial intelligence (AI)/machine learning (ML)-informed californium chi-nuclear data experiment (AIACHNE) project was formed to (a) investigate these discrepancies utilizing AI/ML methods to identify outlying regions of literature data, assign these regions to features of the experiment itself, and perform an improved evaluation of the ${}^{252}\mathrm{Cf}$ PFNS and (b) perform a new experimental measurement of this quantity designed to improve upon the existing literature database. In this work we report on the AIACHNE ${}^{252}\mathrm{Cf}$ PFNS experiment utilizing a new analysis method uncorrelated with all previous measurements: neutron efficiency determinations based on elastic neutron scattering on ${}^{12}\mathrm{C}$ and ${}^9\mathrm{Be}$. This new method provides an independent test of the existing literature data and evaluation of the ${}^{252}\mathrm{Cf}\left(\mathrm{sf}\right)$ PFNS. The method is described with detailed covariance quantification procedures, as well as a direct discussion of the sources of uncertainty described as requirements in the “Templates” series of papers. The ${}^{252}\mathrm{Cf}\left(\mathrm{sf}\right)$ PFNS reported in this work agrees well with the overall shape of the existing standard PFNS evaluation as well as many literature measurements, thus verifying the current evaluation utilizing new techniques. However, the results suggest that there are deficiencies in the angle-differential ${}^{12}\mathrm{C}$ and ${}^9\mathrm{Be}(n,n)$ evaluated nuclear data, which produce unphysical structures in the reported result. While these structures are relatively minor, they become obvious because of the high statistical precision of the data and the expected smooth continuity of the ${}^{252}\mathrm{Cf}\left(\mathrm{sf}\right)$ PFNS.

Under an appropriate scaling the experimental spectra of $\sigma E$ for all heavy-ion fusion excitation functions appear as horizontal curves, located on the $y$ axis at values corresponding to $R_g^2{W}_g$, where $R_g$ and $W_g$ are fit parameters obtained from the single-Gaussian barrier distribution model. In this presentation, the spectra occupy a narrow $Y$ range, and neighboring fusion systems exhibit parallel curves. Fine structures in the excitation functions are clearly visible, on their respective horizontal curves and separated from each other. The advantages of this new representation are further explored, and the systematic behavior of $R_g^2{W}_g$ and fine structure at high energy are presented, which can be useful for further research and for predicting unmeasured heavy-ion fusion cross sections.

Modern Brueckner-Hartree-Fock (BHF) calculations are very successful in describing various properties of symmetric and asymmetric nuclear matter. Within BHF theory, a microscopic optical potential (MOP) for nucleon-nucleus scattering is developed. First, we parametrize the energy and density dependence of complex optical potentials in nuclear matter based on BHF calculations, and then we construct the MOP for finite nuclei with the local density approximation extended to include the finite-range effects. The density distribution and the spin-orbit contribution are calculated from the Hartree-Fock approximation with the LNS5 Skyrme interaction, the latter being constrained by the BHF results. The central real and imaginary potentials turn out to be quantitatively consistent with the phenomenological global Koning-Delaroche potentials. The performance of MOP is evaluated by considering neutron and proton scattering on ${}^{40,48}\mathrm{Ca}$. The elastic-scattering differential cross sections, analyzing powers, total and reaction cross sections are analyzed in the energy range below 200 MeV. A good agreement between the theoretical results and the measurements is achieved. Since our results are presented in analytic forms, they can thus be used easily in the analysis of the experimental data of the nucleon scattering on exotic nuclei.

Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, we systematically investigate the in-medium effects of nucleon-nucleon ($NN$) cross sections on nucleonic and pionic observables in heavy-ion collisions, employing microscopic cross sections derived from the Brueckner-Hartree-Fock approach. Key observables include nuclear stopping, the neutron-to-proton ($n/p$) ratio, neutron-proton transverse flow differences, differential collective flow, pion multiplicities, and the resulting ${({\pi }^{-}/{\pi }^{+})}_{\text{like}}$ ratio. The analysis disentangles the respective contributions from the scattering amplitude, the density of states, and the total momentum ($K$) of the colliding pairs. We find that larger in-medium $NN$ cross sections generally enhance free nucleon emission and nuclear stopping with the nucleon effective mass playing a dominant suppressive role. However, it is insufficient to account only for the medium corrections from effective mass: both the medium effect from the scattering amplitude and the $K$ dependence exert noticeable influences on the observables. In particular, nuclear stopping is found to be highly sensitive to these in-medium modifications of cross sections. While the $n/p$ ratio and transverse flow difference remain largely insensitive, the differential collective flow and pion yields are strongly affected. These results indicate that the interplay between scattering amplitude, density-of-states and $K$ dependence is essential to accurately describe medium effects in heavy-ion collisions.

Background: Nucleon transfer reactions in heavy-ion collisions offer valuable insights into nuclear structure and reaction dynamics. These reactions are sensitive to shell structure, pairing correlations, and collective excitations. Theoretical interpretation of transfer reactions requires taking into account coupling among elastic, inelastic, and transfer of nucleons, necessitating theoretical formalisms based on the coupled reaction channel (CRC) approach.

Purpose: This study investigates one- and two-proton transfer channels in interactions of ${}^{19}\mathrm{F}$ with ${}^{100}\mathrm{Mo}$. The role of different inelastic excited states of the interacting nuclei in shaping angular distributions and the excitation functions is explored.

Method: The angular distribution measurements were carried out at $E_{\mathrm{lab}}=55.5$, 60, 66, and 72 MeV, while the transfer excitation function measurements were performed in the energy range $E_{\mathrm{lab}}$ = 42–72 MeV at different angles viz. at ${\theta }_{\mathrm{lab}}={80}^{\circ }, {100}^{\circ }, {120}^{\circ }, {140}^{\circ }$, and ${160}^{\circ }$. The projectile-like particles were identified using HYTAR ($\mathrm{\Delta }E-E$) telescope detectors at Inter-University Accelerator Centre, New Delhi. CRC calculations incorporating inelastic excitations of interacting nuclei were performed using the potential parameters derived from elastic $+$ inelastic scattering data.

Results: CRC analysis indicates a dominant contribution of low-lying excited states of ${}^{19}\mathrm{F}$ in shaping and enhancing the transfer cross sections. The $2^{+}$ and $3^{-}$ states of ${}^{100}\mathrm{Mo}$ further enhanced cross sections, highlighting its collective nature. Angular distributions exhibited a shift of peak cross sections towards forward angles with increasing beam energy. Transfer excitation functions peak near the Coulomb barrier, particularly at backward angles.

Conclusion: The transfer angular distribution and excitation functions for both one- and two-proton transfer (stripping) channels underscore the role of inelastic states of the ${}^{19}\mathrm{F}$ and ${}^{100}\mathrm{Mo}$ nucleus in influencing transfer processes. These measurements affirm that detailed CRC calculations are essential to understand the complex dynamics of transfer mechanisms, especially in odd-even systems. The present study highlights the need for systematic measurements across different mass regions to understand the interplay between structure and reaction dynamics.

The neutron-to-proton $(N/Z)$ equilibration and nucleon-transfer dynamics in heavy-ion fusion reactions leading to the superheavy nucleus ${}^{297}\mathrm{Og}$ are investigated within the dinuclear system model with a dynamical potential-energy surface (DNS-DyPES model). By studying a series of reactions induced by ${}^{44–55}\mathrm{Ca}$ on Cf isotopes, the influence of entrance-channel $N/Z$ asymmetry on fusion probability and equilibration dynamics was analyzed. It is found that reactions induced by neutron-deficient and neutron-rich projectiles exhibit a potential-energy peak at the incident point, resulting in a lower fusion barrier and a higher fusion probability. Analysis of the time evolution of the mean $N/Z$ indicates that $N/Z$ equilibration occurs within approximately 0.5 zs, and the characteristic time decays exponentially with increasing potential energy at the incident point. After reaching $N/Z$ equilibration, all systems evolve along the same trajectory on the potential-energy surface, confirming that mass and charge transfer proceed along the lowest-energy path. An analysis of the projectilelike fragment distributions indicates that $N/Z$ equilibration corresponds to an early-time redistribution of fragment distribution probabilities driven by the potential energy.

Femtoscopy with photon pairs is a particularly attractive tool for studying high-energy nuclear collisions. Proposed and extensively discussed in several influential theory articles, it has seen only a few applications in experiment because of statistics limitations. With the progress of detectors and electronics, only now is it coming within reach. In this paper we discuss the choice of kinematic variables for two-photon correlation functions. In particular, we argue against $C\left(Q_{\mathrm{inv}}\right)$ and in favor of $C(\mathrm{\Delta }E,Q_{\mathrm{inv}})$.

We investigate how the temperature influences the threshold cusps in meson-meson scatterings, i.e., $\pi \pi$ and $D{\overline{D}}^{*}$ (or $D^{*}\overline{D}$) scatterings, using the production rates and propagators obtained at finite temperature. The line shape of production rate of $\pi \pi$ at different temperatures demonstrates that the cusp structure in $\pi \pi$ scattering is mildly enhanced as the temperature increases. For the $\pi \pi$ propagator, which includes isospin symmetry breaking, the line shape displays a unique plateaulike structure, and this structure will also be enhanced as the temperature increases. For comparison, the line shape of the $D{\overline{D}}^{*}$ propagator including isospin symmetry breaking is also investigated at different temperatures. As the temperature increases, its line shape shows a similar plateaulike structure but with some different properties when the temperature modifications to the masses and widths of $D$ and ${\overline{D}}^{*}$ are considered.

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.