Recent experimental studies have demonstrated the significance of using heavy-ion beams (${}^{50}\mathrm{Ti}, {}^{51}\mathrm{V}$, or ${}^{54}\mathrm{Cr}$) with actinide targets in the production of superheavy nuclei. In the present work, we report the measurement of quasielastic scattering for a hot fusion system, ${}^{48}\mathrm{Ti}+{}^{232}\mathrm{Th}$, leading to the formation of the superheavy nucleus ${}_{112}{}^{280}\mathrm{Cn}$ (copernicium). The purpose of this measurement is to obtain the reaction barrier distribution by exploiting unitarity, specifically by measuring the flux reflected from the Coulomb barrier at backward angles. In the synthesis of such superheavy nuclei, complications arise from events originating from deep-inelastic collisions; to separate these events, an approximate method is employed. The remaining quasielastic events provide an excellent representation of the external Coulomb barriers (or reaction barriers), which in turn reveal intricate details about the reaction mechanism in the ${}^{48}\mathrm{Ti}+{}^{232}\mathrm{Th}$ system. Notably, the position of the barrier distribution and its overall width are found to be well defined. Present studies also suggest that the superheavy-nuclei mass region is sensitive not only to target excitations but also to the projectile's strong internal structure.

Background: Experimental data on the breakup cross sections of weakly bound nuclei, especially ${}^9\mathrm{Be}$, are essential and particularly interesting, in order to understand the underlying reaction mechanisms and its Borromean-like nuclear structure. However, very few data are available in the literature.

Purpose: The aim is to understand the possible reaction mechanisms in the ${}^{209}\mathrm{Bi}({}^9\mathrm{Be},{}^8\mathrm{Be}\to 2\alpha )$ reaction by measuring the cross sections of the $2\alpha$ breakup of the projectile ${}^9\mathrm{Be}$.

Methods: A large Si strip detector array covering an angular range of about ${100}^{\circ }$ was used to carry out exclusive measurements of $2\alpha$ events for the above reaction at $E_{\mathrm{beam}}=47\mathrm{MeV}$. The distribution of $E_{{\alpha }_1}$ versus $E_{{\alpha }_2}, E_{\mathrm{rel}}, Q$ value, and $E_{\mathrm{rel}}$ versus $Q$ value were analyzed to identify different mechanisms of $\alpha$ production. Monte Carlo–simulated detector efficiencies were employed to determine breakup cross sections. The continuum-discretized coupled-channels (CDCC) calculations were performed, modeling ${}^9\mathrm{Be}$ as a cluster of $n+{}^8\mathrm{Be}$, to interpret the measured cross sections for various outgoing channels.

Results: The distribution of $Q$ value versus $E_{\alpha \alpha }$ indicates the dominance of the events corresponding to the ${}^{209}\mathrm{Bi}({}^9\mathrm{Be},{}^8\mathrm{Be}\to 2\alpha )$ reaction, particularly at larger $Q$ values ($Q\ge 0$). Differential cross sections for the $1n$ stripping followed by breakup of ${}^8\mathrm{Be}$ into $2\alpha$, along with the elastic, inelastic, and $1n$-pickup channels, were derived and interpreted using the CDCC and Coupled Reaction Channels (CRC) formalisms. The coupling effects of transfer, breakup, and inelastic channels on the elastic channel were found to be highly significant.

Conclusions: Using appropriate experimental and analytical techniques, it was possible to obtain absolute cross sections for the ${}^{209}\mathrm{Bi}({}^9\mathrm{Be},{}^8\mathrm{Be}\to 2\alpha )$ reaction. A simultaneous description of elastic, inelastic, transfer, and breakup channels using a unified coupled-channels calculation was also possible, which suggests that modeling ${}^9\mathrm{Be}$ as a cluster of $n+{}^8\mathrm{Be}$ is a reasonable assumption. The coupling of breakup channels was found to generate an attractive polarization potential, whereas the coupling of inelastic and transfer channels introduces a repulsive polarization potential.

We study the impacts of the squeezing effect caused by in-medium mass modification on the Hanbury- Brown–Twiss (HBT) correlation of $\varphi \varphi$ using a hydrodynamical source. The squeezing effect reduces the influence of transverse flow on the transverse distribution of the $\varphi$ emitting source while expanding the longitudinal source distribution. This trend becomes more noticeable as the transverse momentum increases, resulting in an enlargement of the HBT radii for $\varphi \varphi$. Notably, this enlargement is particularly evident with higher transverse pair momentum. As a result, the HBT radii of $\varphi \varphi$ increase as the transverse pair momentum increases instead of showing a consistent decrease, showcasing the nonflow behavior of HBT radii in hydrodynamical sources. Both Gaussian fitting and Lévy fitting support the conclusion.

The possible existence of wobbling nuclei in the odd-mass isotope chains of ${}^{161-169}\mathrm{Tm}$, ${}^{161-169}\mathrm{Lu}$, and ${}^{161-169}\mathrm{Ta}$ within the $A\approx 160$ nuclei are investigated. The relativistic density functional theory is employed to systematically calculate the configuration, parity, and deformation information of these nuclei. Taking ${}^{167}\mathrm{Ta}$ as an example, the particle triaxial-rotor model is used to study the wobbling motion built on the $\pi {\left(1h_{9/2}\right)}^1$ configuration. The energy spectra, electromagnetic transition probability, as well as the angular momentum geometry suggest the existence of a wobbling mode. Hence, ${}^{167}\mathrm{Ta}$ may be a multiple wobbling nucleus based on the previously observed $i_{13/2}$ configuration and currently studied $h_{9/2}$ configuration.

The suppression of the neutron superfluid fraction in the inner crust of a cold neutron star is mitigated by the quantum zero-point motion of ions about their equilibrium position. In turn, the crustal dynamics is altered by the presence of the neutron superfluid. These effects are studied self-consistently to assess the validity of the usual assumption of a perfect rigid lattice. To this end, fully three-dimensional band-structure calculations of the superfluid fraction are carried out in the weak-coupling approximation, considering body- and face-centered cubic lattices. In both cases, the superfluid fraction is still found to be strongly suppressed in the intermediate region of the inner crust. In turn, the effective mass of the ions is dramatically increased, thus further damping the ion fluctuations. These results are of relevance for the rotational and thermal evolutions of neutron stars.

The geometric similarity of wave functions assuming isoscalar spin-aligned and isovector pairing correlations challenges our understanding of the isospin nature for nucleon pairs in low-lying nuclear states. Instead of energy levels and electromagnetic properties, integrated Gamow-Teller decay rates are found to be sensitive and parameter-free quantities to discriminate between the two scenarios in ${}^{96}\mathrm{Cd}$. Analytical formulas of the decay rates for $T=0$ yrast states of ${}^{96}\mathrm{Cd}$ are derived from a single-$j$ ($g_{9/2}$) shell, the validity of which model space is supported by examining details of Gamow-Teller transition rates with shell-model calculations using three sets of effective interactions in the $f_{5}p{g}_9$ shell. The experimental $logft$ value of the $0_1^{+}$ ground state does not conform with spin-aligned pair condensation and is more appropriate to interpret in terms of the conventional isovector pairing correlation; on the other hand, for the isomeric ${16}_1^{+}$ state, the experimental datum is well consistent with the isoscalar spin-aligned pair condensation.

${}^{146}\mathrm{Sm}$, as an extinct $p$-process isotope, plays an irreplaceable role in the timeline construction of the early solar system (ESS) via the geochemical tracing of its $\alpha$ decay to ${}^{142}\mathrm{Nd}$. There have been persistent discrepancies among both measured and theoretical half-lives of ${}^{146}\mathrm{Sm}$, which result in a large uncertainty in the initial ${}^{146}\mathrm{Sm}$ abundance in the ESS and subsequent dating of planetary events after the birth of the Sun. In this study, a newly proposed technique was used to analyze the $\alpha$ decay process within the widely employed $\alpha$-core nuclear potentials, namely, three different Woods-Saxon shapes and the double-folding potential. The half-life is obtained through large-scale random sampling of parameters for each potential, with the robust results subjected to statistical analysis. Additionally, a well-founded extrapolation for $\alpha$ decay energy of ${}^{146}\mathrm{Sm}$, based on the systematic behavior of the neighboring decay chain, is in perfect agreement with the adopted experimental value, further supporting the present evaluation on this crucial half-life. As a result, the half-life of ${}^{146}\mathrm{Sm}$ was determined to be $71.74\pm 7.39$ million years (Ma) with a 95% confidence interval. The initial ${}^{146}\mathrm{Sm}/{}^{144}\mathrm{Sm}$ ratio of $0.0092\pm 0.0014$ at 4568($\pm 10$) Ma, corresponding to the formation of the solar system, is then determined, further leading to a reduced timescale for various planetary silicate mantle differentiation events of the ESS. It is expected that this study paves the way for a theoretically calibrated ${}^{146}\mathrm{Sm}\text{−}{}^{142}\mathrm{Nd}$ chronometer in future studies of nucleosynthesis and in earth and planetary astrophysics.

The main goal of this study was to enhance the knowledge of the properties of the known octupole rotational band in ${}^{71}\mathrm{Ge}$, including transition rates, and to investigate whether the band persists to higher spin. An experiment at Florida State University using the ${}^{62}\mathrm{Ni}({}^{14}\mathrm{C},$ $\alpha n)$ reaction at 50 MeV was used to produce ${}^{71}\mathrm{Ge}$ at high spin. An array of ten Compton-suppressed Ge detectors, consisting of three Clover detectors and seven single-crystal detectors, was used to measure the $\gamma$ decays in coincidence. An analysis of the resulting coincidence spectra resulted in the placement of 13 additional transitions in the ${}^{71}\mathrm{Ge}$ level scheme, one of which (1092 keV) extends the octupole band to a $(35/2^{-})$ state at 8206 keV. However, calculations of the kinematic moment of inertia show that the 1092-keV transition disrupts the rigid rotational pattern and is likely associated with a band crossing, potentially quenching the octupole deformation. Transition strengths inferred from lifetime measurements in the octupole band are not well reproduced by either shell-model calculations using the JUN45 interaction or a semimicroscopic cluster model, while those for the $\nu g_{9/2}$ band are in good agreement with the corresponding shell-model predictions. Comparisons between the octupole band in ${}^{71}\mathrm{Ge}$ and negative-parity bands based on $3^{-}$ octupole states in some neighboring even-even nuclei show both similarities and differences. Systematic trends within the $\nu g_{9/2}$ bands among odd-$A$ Ge isotopes point to increased collectivity near $N=40$.

The $(\gamma ,n)$ cross sections for the ${}^{59}\mathrm{Co}$ isotope within the range of giant dipole resonance were measured using laser Compton scattering (LCS) $\gamma$ rays at the Shanghai Laser Electron Gamma Source (SLEGS), Shanghai Synchrotron Radiation Facility (SSRF). A new neutron flat efficiency detector (FED) array was employed for neutron detection, and a BGO detector with 100% efficiency was utilized to precisely determine the energy distribution of the LCS radiation. The incident energy of $\gamma$ was adjusted from $E_{\gamma }=10.52\mathrm{MeV}$ to 18.95 MeV by adjusting the collision angles of the laser to the electron beam in the SSRF storage ring and compared with the experimental data and the TENDL-2023 evaluated data. The experimental results are significantly different from those of the Livermore and other bremsstrahlung-generated $\gamma$ source, but better agree with those measured by the LCS $\gamma$ source. The measurement data were used as experimental constraint to extract the gamma strength function $\left(\gamma \mathrm{SF}\right)$, and the inverse reaction cross section of ${}^{58}\mathrm{Co}(n,$ $\gamma )$ was subsequently calculated.

Background: Multinucleon transfer (MNT) reactions in actinide systems are a promising method to synthesize transuranium neutron-rich elements. Appropriate theoretical approaches are needed to understand the mechanisms behind MNT.

Purpose: We employ a microscopic approach to calculate neutron-rich isotope production in the reaction ${}^{238}\mathrm{U}+{}^{248}\mathrm{Cm}$ system.

Methods: The stochastic mean-field (SMF) approach is used to calculate the primary cross sections in MNT reactions based on the quasifission and inverse quasifission processes, and a statistical de-excitation model with gemini++ code to calculate the secondary fragment cross sections.

Results: The calculated cross sections using SMF and $\mathrm{GEMINI++}$ explain available experimental results for the ${}^{238}\mathrm{U}+{}^{248}\mathrm{Cm}$ system at $E_{\mathrm{c}.\mathrm{m}.}=898.7$ MeV energy. This shows the effectiveness and applicability of the quantal diffusion approach, based on the SMF theory, in heavy-ion collisions.

Conclusions: Production of transuranium neutron-rich elements with a proton number up to $Z=101$ is obtained with sizable cross sections. Theoretical results calculated for the $Z=102–105$ region, for which there are no experimental data, show that the cross-section values would be lower than the microbarn level. SMF theory does not contain any adjustable parameters other than the standard parameters of the energy density functional used in the TDHF theory and is an important approach for the microscopic understanding of reaction mechanisms.

In this work, we perform a detailed study of the thermodynamical properties of asymmetric nuclear matter at finite temperatures by means of the Gogny force, with a particular focus on its D1 family. We emphasize the investigation of the liquid-gas phase transition with the respective analysis of phase-coexistence boundaries (binodal sections) and instability regions (spinodal contours). Furthermore, the phenomenon of isospin distillation, intrinsically related to the unstable part of the system, is also described. In order to estimate the impact of the finite range of the nuclear interaction, for each Gogny parametrization we provide a respective zero-range Skyrme version, for which the free parameters of the model are obtained with the aim of reproducing at zero temperature the same saturation density, binding energy, incompressibility, isoscalar effective mass, isovector effective mass, symmetry energy, and symmetry energy slope. As a main result, we verify systematic deviations between the Gogny models and their Skyrme-version models, particularly at higher temperatures, where the Skyrme-version parametrizations exhibit reduced binodal and spinodal regions.

The ground-state properties of 2410 nuclei from C ($Z=6$) to Cm ($Z=96$) have been systematically studied using the Sky3D model, which is based on the Skyrme-Hartree-Fock $\left(\mathrm{SHF}\right)+$ Bardeen-Cooper-Schrieffer (BCS) method, with the Skyrme interactions from SV-mas07I to SV-mas07IV. The effects of spin-orbit interaction and pairing on the binding energy per nucleon, the quadrupole deformation parameter ${\beta }_2$, and the charge radius of nuclei have been investigated. The calculated results were compared with available experimental data from the atomic mass evaluation (AME2020), the results of the finite range droplet model (FRDM2012), and the available compiled database of the nuclear ground-state charge radius. It was shown that the spin-orbit interaction can significantly affect the magic nuclei and their neighboring nuclei, increasing the binding energy per nucleon closer to the experimental values compared to the case without spin-orbit interaction. Additionally, it can adjust the shapes of magic nuclei to the expected spherical shape and reduce the overestimated charge radii of nuclei, making them closer to the experimental measurements. Pairing has a relatively weaker impact than the spin-orbit interaction, but it can also bring the ground-state properties of nuclei closer to the experimental data or FRDM2012 results. Together, the spin-orbit interaction and pairing can enhance the accuracy of the Sky3D model in describing the ground-state properties of nuclei to a very good precision. Specifically, the root mean square (rms) deviation of the binding energy per nucleon compared to AME2020 is 0.268 MeV; the rms deviation of the quadrupole deformation parameter ${\beta }_2$ compared to the FRDM2012 results is 0.229; for the charge radii compared to the experimental data in the CR2013 database, the value is 0.0319 fm, and compared to the experimental data in the CR2021 database, the value is 0.0290 fm.

Background: In previous works we have studied the one-neutron transfer reactions induced by ${}^{13}\mathrm{C}$ on ${}^{27}\mathrm{Al}$ and ${}^{28}\mathrm{Si}$ nuclei. Using a multichannel approach, experimental cross sections for elastic, inelastic, and transfer reactions are well described with the same theoretical formalism.

Purpose: In this work we apply the same approach to intermediate mass-target nuclei and analyze the one-neutron transfer on the ${}^{144,148}\mathrm{Sm}$ isotopes. We study the reliability of our theoretical formalism in the middle-mass nuclei and the effects of neutron excess of the ${}^{148}\mathrm{Sm}$ on the transfer cross sections.

Methods: Elastic and one-neutron stripping reactions for the ${}^{13}\mathrm{C}+{}^{144,148}\mathrm{Sm}$ systems were measured at ${\mathrm{E}}_{\mathrm{lab}}=56$ and 60 MeV. Inelastic cross sections were also obtained for the ${}^{144}\mathrm{Sm}$ target. Coupled reaction-channel calculations were performed and compared to experimental data.

Results: The overall shape of the angular distributions for the transfer reactions are reproduced using spectroscopic amplitudes from a shell model with larger deviations for the one-transfer data to ${}^{144}\mathrm{Sm}$ target.

Conclusions: Comparisons with spectroscopic factors for ${}^{145}\mathrm{Sm}$, previously measured with the light-ion beams, suggest that couplings to other reaction channels and the spectroscopic amplitudes obtained from shell models must be scrutinized.

Background: The value of the shear viscosity $\eta$ and the diffusion coefficients of conserved charges ${\kappa }_{ij}$ with $i,j\in \{B,Q,S\}$ strongly depend on the microscopic interactions of the constituents.

Purpose: Study the effects of multiparticle reactions, angular distributions, and additional elastic cross sections via the additive quark model description, the numbers of degrees of freedom, and the baryon density on the transport coefficients.

Method: $\eta$ and ${\kappa }_{ij}$ are extracted from infinite matter simulations of the hadronic transport model SMASH using the Green-Kubo formalism. The transport coefficients are then obtained by integrating the correlation functions which have been thoroughly checked and compared to kinetic theory calculations. We then systematically study the collision term dependence of $\eta$ and ${\kappa }_{ij}$ by switching the respective cross sections on and off. With this method we are able to extract the relevant interactions and dependencies for $\eta$ and ${\kappa }_{ij}$.

Results: We find that multiparticle reactions decrease the shear viscosity in a simplified hadron gas whereas the electric charge diffusion coefficient is not modified. Furthermore, additional elastic cross sections have a strong impact on both $\eta$ and ${\kappa }_{ij}$, whereas anisotropic scatterings enhance the shear viscosity in the full hadron gas. When the number of degrees of freedom is increased, the shear viscosity is only slightly modified in comparison to the diffusion coefficients. Finally, the calculation at a finite baryon chemical potential reveals that the shear viscosity itself does not depend on ${\mu }_B$ but on the ratio $\eta /s$. The diffusion coefficients show a strong dependency which we compare to Chapman-Enskog calculations.

Conclusions: We conclude that the behavior of the shear viscosity is highly sensitive to the individual treatment of the cross sections. The diffusion coefficients of conserved charges are affected by the averaged cross sections and the charge densities. These results help understand observables when modeling heavy-ion collisions as well as open the opportunity for a better understanding when comparing to first-principles calculations.

We present an energy-loss model which includes small system size corrections to both the radiative and elastic energy loss. Our model is used to compute the nuclear modification factor $R_{AB}$ of light and heavy flavor hadrons averaged over realistic collision geometries for central and peripheral $A+A$ and central $p/d/{}^3\mathrm{He}+A$ collisions at the CERN Large Hadron Collider and the BNL Relativistic Heavy Ion Collider. We find that the predicted suppression in small systems is almost entirely due to elastic energy loss. Our results are keenly sensitive to the crossover between elastic energy loss calculated with hard thermal loop propagators and vacuum propagators, respectively, which leads to a large theoretical uncertainty. We find that the $R_{AB}$ is largely insensitive to the form of the elastic energy-loss distribution—Gaussian or Poisson—surprisingly so in small systems where the central limit theorem is inapplicable. We present an expansion of the $R_{AB}$ in terms of the moments of the energy loss probability distribution, which allows for a rigorous understanding of the dependence of the $R_{AB}$ on the underlying energy-loss distribution.

An extension of time-dependent density functional theory (TDDFT), the generalized time-dependent generator coordinate method (TDGCM) is applied to a study of induced nuclear fission dynamics. In the generalized TDGCM, the correlated nuclear wave function is represented as a coherent superposition of time-dependent DFT trajectories. In the first realistic application, a large basis of 25 TDDFT trajectories is employed to calculate the charge yields and total kinetic energy distribution for the fission of ${}^{240}\mathrm{Pu}$. The results are compared with available data, and with those obtained using a standard TDDFT, that does not consider quantum fluctuations, and the adiabatic $\mathrm{TDGCM}+\mathrm{GOA}$ (Gaussian overlap approximation). It is shown that fragment yields and kinetic energies can simultaneously be described in a consistent microscopic framework that includes fluctuations in the collective degrees of freedom and the one-body dissipation mechanism.

The possibility of observing wobbling mode in the even-even systems of ${}^{76}\mathrm{Ge}, {}^{112}\mathrm{Ru}, {}^{188,192}\mathrm{Os}, {}^{192}\mathrm{Pt}$, and ${}^{232}\mathrm{Th}$ is explored using the triaxial projected shell model approach. These nuclei are known to have $\gamma$ bands whose odd-spin members are lower than the average of the neighboring even-spin states. It is shown through a detailed analysis of the excitation energies and the electromagnetic transition probabilities that the observed band structures in these nuclei except for ${}^{232}\mathrm{Th}$ can be characterized as originating from the wobbling motion. It is further demonstrated that quasiparticle alignment is responsible for driving the systems to the wobbling mode.

The ($n,\gamma$) cross section of the nuclide ${}^{168}\mathrm{Yb}$, which is one of 35 $p$-nuclei, plays an important role in nuclear astrophysics network calculations. The ${}^{168}\mathrm{Yb}$ resonance parameters, ${\mathrm{\Gamma }}_{\gamma }$ and ${\mathrm{\Gamma }}_n$, show significant discrepancies between these evaluated nuclear data libraries, while existing experimental data remain insufficient to resolve them. In this study, the ($n,\gamma$) yield of ${}^{\mathrm{nat}}\mathrm{Yb}$ is measured at the Back-n facility of the Chinese Spallation Neutron Source using the time-of-flight method. The ${\mathrm{\Gamma }}_{\gamma }$ and ${\mathrm{\Gamma }}_n$ parameters of ${}^{168}\mathrm{Yb}$ are extracted by the multilevel $R$-matrix Bayesian code sammywithin the energy range of 0.1–300 eV. Both the ${\mathrm{\Gamma }}_{\gamma }$ and ${\mathrm{\Gamma }}_n$ parameters at three resonance peaks of 0.58, 22.53, and 27.17 eV are obtained successfully. Among them, the ${\mathrm{\Gamma }}_{\gamma }$ value at 27.17 eV is experimentally extracted to be 65.88 $\pm$ 5.80 meV for the first time. These resonance results are further compared with the available evaluated and experimental data. It is found that the extracted ${\mathrm{\Gamma }}_{\gamma }$ values are in good agreement with the nuclear data libraries ENDF/B-VIII.0, JENDL-4.0, BROND-3.1, and JEFF-3.3. Meanwhile, the extracted ${\mathrm{\Gamma }}_n$ value at 0.58 eV is consistent with TENDL-2019, whereas the ${\mathrm{\Gamma }}_n$ values at two other resonance peaks are different from the existing data. These findings enrich the experimental data of the ${}^{168}\mathrm{Yb}$ neutron capture resonance and emphasize the importance of selecting appropriate nuclear data libraries.

The angular distributions for various reaction channels like elastic scattering, $\alpha$ particles, and projectile like fragments (${}^{6,7}\mathrm{Li}, {}^{9,10}\mathrm{Be}$, and ${}^{11}\mathrm{B}$) production have been measured with ${}^{10}\mathrm{B}$ projectile on ${}^{159}\mathrm{Tb}, {}^{197}\mathrm{Au}$, and ${}^{209}\mathrm{Bi}$ targets at 54 MeV beam energy. The reaction cross sections were obtained from the optical model analysis of the elastic scattering data. $\alpha$-particle production was found to be dominant over other particles production for all the three targets. The sum of measured particle production cross sections and complete fusion cross sections are found to match reasonably well with the reaction cross sections. Further, the reaction cross sections with ${}^{10}\mathrm{B}$ projectile from literature and present data on several targets show a systematic universal behavior. The data available for complete and incomplete fusion cross sections also show a systematic behavior. The contribution of incomplete fusion in $\alpha$-particle production was also extracted.