Coupled-cluster theory is a powerful tool for first-principles calculations of atomic nuclei, enabling accurate predictions of nuclear observables across the Segrè chart. While coupled-cluster computations are especially efficient at shell closures, extensions have been developed to tackle open-shell nuclei, by exploiting the equation-of-motion method or by expanding the coupled-cluster wave function on top of a symmetry-breaking (either deformed or superfluid) reference state. In this study, we provide a comprehensive comparison of these different formulations applied to the calcium and nickel isotopes using nuclear two- and three-body interactions from chiral effective field theory. Based on ground-state energies, two-neutron separation energies, and two-neutron shell gaps, different coupled-cluster computations—based on symmetry-broken reference states and equation-of-motion techniques—offer consistent descriptions of bulk properties across medium-mass isotopic chains.

Actinide nuclei provide a suitable platform for studying laser-assisted nuclear $\alpha$ decay, with potential applications in nuclear transmutation, nuclear radiotherapy, and nuclear battery regulation. In the present work, we develop a deformed one-parameter model to quantitatively evaluate the impact of ultra-intense laser fields on the $\alpha$ decay of actinide nuclei. Our calculations demonstrate that, under laser intensities expected at near-future laser facilities, the $\alpha$-decay half-lives of these nuclei can be modified to a non-negligible extent, on the order of 0.01% to 0.1%. Furthermore, we reveal key insights into the laser-nucleus interaction: from the nuclear perspective, the laser field’s effect on $\alpha$ decay is governed by the nuclear shell structure and decay energy, with $\alpha$-emitting nuclei featuring lower decay energies and greater distance from neutron shell closures exhibiting higher susceptibility to laser fields. From the laser driver perspective, we proposed a bichromatic laser scheme to enhance the average effects of a single laser pulse on $\alpha$-tunneling probability. Specifically, with appropriate phase conditions and amplitude ratios, it is shown that a fundamental–second-harmonic ($\omega \text{−}2\omega$) bichromatic field can increase the time-averaged modification by one to two orders of magnitude.

Two back-to-back experiments, ${}^{28}\mathrm{Si} + {}^{178}\mathrm{Hf}$ and ${}^{28}\mathrm{Si} + {}^{186}\mathrm{W}$, were intentionally conducted to validate the role of shell closure in pre-actinides by studying neutron multiplicity in compound nucleus (CN) ${}^{206}\mathrm{Rn}$ and ${}^{214}\mathrm{Ra}$. In the first experiment [Dubey et al., Phys. Rev. C 112, L011602 (2025)], we established the influence of the neutron-shell closure. In the present work, the CN ${}^{214}\mathrm{Ra}$ was deliberately selected to investigate the dependence of the total neutron multiplicity ($M_{\mathrm{total}}$) on the proton number ($Z$), while keeping the neutron number constant at $N$ = 126 in the pre-actinide region. The objective of the study is twofold : (i) to examine the effect of proton-shell closure when moving away from $Z$ = 82, and (ii) to correlate the present results on proton-shell closure with our previous finding on neutron-shell closure. We have also used the previous reported data for $N$ = 126 isotones ${}^{210}\mathrm{Po}, {}^{212}\mathrm{Rn}$, and ${}^{213}\mathrm{Fr}$ to establish the validation of shell closure. A systematic increase in $M_{\mathrm{total}}$ with increasing $Z$ was observed from $Z$ = 82 to $Z$ = 88. Furthermore, comparison of the present results on proton-shell closure with our earlier neutron-shell closure observation, reveals that the cross correlation between neutron- and proton-shell closure shows a systematic increase in $M_{\mathrm{total}}$ as one moves away from ${}^{208}\mathrm{Pb}$, whether along isotonic or isotopic chains.

We report a new measurement of the photoneutron cross section for ${}^{89}\mathrm{Y}(\gamma ,n){}^{88}\mathrm{Y}$ in the energy range of 11.85–18.70 MeV at the Shanghai Laser Electron Gamma Source (SLEGS) using a neutron Flat-Efficiency Detector (FED) array. An iterative unfolding algorithm was combined to extract monoenergetic cross sections with a typical total uncertainty $\sim 3.5\%$. Then the new experimental results are systematically compared with the data from Saclay, Livermore and IAEA/PD-2019, which implies the reliability of our results. Based on the new experimental results, the $\gamma$-ray strength function ($\gamma \mathrm{SF}$) was deduced and used as input for Hauser-Feshbach calculations of the inverse reaction ${}^{88}\mathrm{Y}(n,\gamma ){}^{89}\mathrm{Y}$ using the $\mathrm{TALYS}$ code. Theoretical predictions were based on the Kopecky-Uhl generalized Lorentzian model for $E1$ transitions and the spin-flip scissors model for $M1$ transitions and optimized using a normalization factor $G_{\mathrm{norm}}=1.31$. The calculated ${}^{88}\mathrm{Y}(n,\gamma ){}^{89}\mathrm{Y}$ cross sections are in good agreement with JEFF-3.3, but show deviations from other evaluated nuclear data libraries, including JENDL-5, TENDL-2023, and ROSFOND-2010.

Isobaric collisions provide a unique opportunity to investigate how variations in the charge to mass ratio affect the final state observables produced in relativistic heavy ion collisions. Most importantly, isobaric systems that differ in their nuclear structure offer valuable insights into the underlying nuclear geometries, making them powerful tools to probe the role of nuclear structure using heavy ion collisions. We study the initial state and evolution of the hot and dense medium formed in $\mathrm{Ru}+\mathrm{Ru}$ and $\mathrm{Zr}+\mathrm{Zr}$ collisions at $200A$ GeV at RHIC using a relativistic hydrodynamical model. The initial geometry of the two isobaric collisions is found to influence the evolution of the hot and dense medium produced. The sensitivity of photon production, charged particle spectra, and anisotropic flow coefficients ($v_n$) to the initial geometry, including different orientations of the isobaric set, has been studied in detail. Significant variations in anisotropic flow of photons and hadrons are observed, highlighting the role of nuclear deformation in shaping final state observables. Moreover, photon anisotropic flow is found to be considerably more sensitive to the initial state than charged particle anisotropic flow, indicating that photon measurements in isobaric collisions have strong potential to constrain initial state modeling and improve our understanding of quark-gluon plasma properties in such systems.

We employ the Zubarev approach of the statistical operator to investigate the enhancement of the low-$p_T$ region of pion spectra, introducing an effective pion chemical potential, to describe the overpopulation of low-energy pion states. We test a corresponding freeze-out approach by analyzing the transverse-momentum spectra of identified particles measured recently with high precision by the ALICE Collaboration in $\mathrm{Pb}+\mathrm{Pb}$ collisions at CERN LHC. A blast-wave model and a blast-wave-based particle generator, coupled to a hadronic transport model, are utilized. Bayesian inference methods are applied to extract the most probable sets of thermodynamic parameters at the chemical freeze-out hypersurface. Both models for the overpopulated pion states, the hadronic transport model and the thermal model with a nonzero pion chemical potential, provide a satisfactory description of the observed pion spectra. However, both approaches contain approximations which can be improved within a systematic nonequilibrium approach. We demonstrate that the introduction of a nonequilibrium pion chemical potential offers an efficient alternative to the conventional explanation of the low-$p_T$ enhancement, typically attributed to resonance decays with subsequent thermalization. A similar discussion also holds for the kaon spectra.

Motivated by recent observations of spin polarization and alignment in heavy-ion collisions, we study the impact of rotation on the transport properties of strongly interacting matter within kinetic theory in the relaxation time approximation. Our analysis focuses on the anisotropic shear viscosity—parallel (${\eta }_{\parallel }$), perpendicular (${\eta }_{\perp }$), and Hall (${\eta }_{\times }$)—and electrical conductivity—${\sigma }_{\parallel }, {\sigma }_{\perp }$, and ${\sigma }_{\times }$—induced by the Coriolis force in a rotating medium. We employ two approaches: a combined quark–gluon plasma–hadron resonance gas (QGP-HRG) framework and a two-flavor Nambu–Jona-Lasinio (NJL) model. In the QGP-HRG description, noninteracting HRG (massless partonic) degrees of freedom are used below (above) the transition temperature. In the NJL model, rotation enters through spinorial connections in the Lagrangian, and the constituent quark masses are obtained over the full temperature range. Rotation suppresses the chiral condensate and slightly enhances the transport coefficients for phenomenologically relevant angular velocities. Assuming a temperature-dependent angular velocity consistent with standard cooling, we find that ${\eta }_{\left|\right|,\perp ,\times }/s$ and ${\sigma }_{\perp ,\times }/T$ exhibit a valleylike temperature dependence, with reduced magnitudes compared to the isotropic $\eta /s$ and $\sigma /T$ obtained without rotation. At zero net baryon density, rotation generates a sizable nondissipative Hall-like conductivity, unlike the case with magnetic fields where baryon and antibaryon contributions cancel.

The abnormal behavior of nuclear charge radii can be generally associated with the observed structure phenomena along the specific isotopic family. In this work, the relativistic mean-field theory with the effective Lagrangian NL3 force is employed to feature the systematic trend of changes of charge radii near $N=90$ regions. The pairing correlations are tackled by solving the state-dependent Bardeen-Cooper-Schrieffer equations with a density-dependent zero-range force. The neutron- and proton-pairs correlation around the Fermi surface has been incorporated into the charge radii formula. The potential energy surfaces of even-even rare-earth isotopes with the proton numbers $Z=60$, 62, 64, 66, and 68 are depicted by constraining the axially symmetric quadrupole and hexadecapole moments simultaneously. The calculated results suggest that the strong quadrupole-hexadecapole correlations can be significantly observed from the tilted potential energy surfaces of the corresponding nuclei. Especially, this phenomenon can be obviously predicted near the shape coexistence $N=90$ regions. Meanwhile, the quadrupole-hexadecapole coupling effect plays an indispensable role in reproducing the evolutionary trend of nuclear charge radii with high precision. The calculated results suggest that the modified charge radii formula can improve the local variations of charge radii, especially the odd-even staggering phenomena. Furthermore, this odd-even oscillation trend in charge radii can also be influenced by the pairing force type. This means that charge radii provide a robust indicator to identify the structure phenomena.

The experimental differential cross-section (CS) and analyzing power (AP) data of the ${}^6\mathrm{Li}+{}^{12}\mathrm{C}$ elastic scattering over a wide laboratory energy scale ($4.5\mathrm{MeV}\le E_{\text{lab}}\le 600\mathrm{MeV}$) are analyzed within the framework of the optical model (OPM) using nonmonotonic (NM) nucleus–nucleus potentials. The real part of the NM potentials is derived from the Pauli-embodied energy density-functional (EDF) formalism with the sudden approximation. The real part of the noncentral spin-orbit and tensor terms, as well as the imaginary parts, are treated phenomenologically. The effect of the radius of sensitivity on the CS and AP data is found to be more important at lower energies. The diffractive and refractive scattering with Airy structures in the whole angular region of the elastic scattering across the studied energy range is successfully described within the OPM using the NM ${}^6\mathrm{Li}+{}^{12}\mathrm{C}$ potential. The near- and far-side (N and F) decomposition of the total elastic-scattering amplitudes has also been studied using our NM potentials. The evolution of the Airy minima in the angular distributions, coupled with the fitting of the AP data, provides an accurate description of Airy minima of different orders. The OPM calculations with the NM potentials describe exceptionally well the CS, vector analyzing power (VAP), and tensor analyzing power data at $E_{\text{lab}}=9.0,19.24,20,30,$ and $50\mathrm{MeV}$. In agreement with our previous successful descriptions of CS and the opposite signs of the VAP data for the ${}^6\mathrm{Li}$ and ${}^7\mathrm{Li}$ elastic scattering using NM potentials in OPM, the present results appear to provide a better fit, so far, than those obtained from the coupled-channels method. The fusion cross sections of ${}^6\mathrm{Li}+{}^{12}\mathrm{C}$ have been predicted in the energy range ($4.5\mathrm{MeV}\le E_{\text{lab}}\le 20\mathrm{MeV}$), fitting the experimental data well in the range $E_{\text{lab}}=2.97–11.77\mathrm{MeV}$. The EDF potential without any energy dependence and renormalization is also found to describe satisfactorily the experimental CS and AP data at energies up to several hundreds of MeV.

We present a phase-space excluded-volume approach applicable to both nuclear matter and nonequilibrium processes, such as heavy-ion collisions, to account for in-medium effects on light clusters. In this approach, light clusters can exist only if the nucleon one-body phase-space occupation of the surrounding nuclear medium—including explicit contributions from light clusters—is sufficiently low. The nucleon occupation is determined self-consistently by accounting for the interplay between in-medium effects and thermodynamic properties, thereby improving upon the conventional treatment based on an uncorrelated medium (i.e., an overall nucleonic Fermi-Dirac distribution) typically employed in studies of light clusters in nuclear matter. We apply the approach to evaluate the Mott momenta and the fractions of light clusters in nuclear matter. Their differences from results obtained under the uncorrelated-medium assumption are found to be moderate. The main advantage of the present approach lies in its ability to be integrated into dynamical models, enabling more accurate studies of in-medium effects on light clusters, based on their measured yields in heavy-ion collisions.

We investigate low-energy astrophysical $S$ factors for reactions proceeding through the ${}^8\mathrm{Be}$ compound system with entrance channels $p+{}^7\mathrm{Li}, n+{}^7\mathrm{Be}$, and $d+{}^6\mathrm{Li}$. Using the same microscopic many-channel three-cluster framework as in our previous study of the high-lying ${}^8\mathrm{Be}$ spectrum, we calculate $S\left(E\right)$ for ${}^7\mathrm{Li}(p,\alpha ){}^4\mathrm{He}, {}^7\mathrm{Be}(n,\alpha ){}^4\mathrm{He}, {}^7\mathrm{Be}(n,p){}^7\mathrm{Li}, {}^6\mathrm{Li}(d,\alpha ){}^4\mathrm{He}, {}^6\mathrm{Li}(d,p){}^7\mathrm{Li}$, and ${}^6\mathrm{Li}(d,n){}^7\mathrm{Be}$ in the energy range relevant for primordial and stellar nucleosynthesis. For the mirror reactions ${}^7\mathrm{Li}(p,\alpha ){}^4\mathrm{He}$ and ${}^7\mathrm{Be}(n,\alpha ){}^4\mathrm{He}$, as well as for ${}^7\mathrm{Be}(n,p){}^7\mathrm{Li}$ the calculated $S$ factors reproduce both the absolute scale and the low-energy trends of the experimental data within their quoted uncertainties, whereas the absolute $S$ factors for the deuteron-induced channels on ${}^6\mathrm{Li}$ are underestimated at low energy, consistent with the shifted ${}^6\mathrm{Li}+d$ threshold and the absence of a broad subthreshold $2^{+}$ structure in the present implementation. A partial-wave analysis identifies the dominant $J^{\pi }$ contributions in each channel and relates them to specific ${}^8\mathrm{Be}$ resonances, while demonstrating that cluster polarization, previously shown to be crucial for the ${}^8\mathrm{Be}$ spectrum, is likewise essential for the normalization and energy dependence of several $S$ factors. Evaluating $S\left(E\right)$ at appropriate Gamow energies, we obtain a hierarchy of reaction channels that quantifies the relative importance of neutron- and deuteron-induced processes for the production and destruction of ${}^7\mathrm{Li}$ and ${}^7\mathrm{Be}$.

Background: The ${}^3\mathrm{He}(\alpha ,\gamma ){}^7\mathrm{Be}$ reaction plays a crucial role in the proton-proton chain and Big Bang nucleosynthesis, affecting solar neutrino fluxes and primordial element abundances. Experimental data at astrophysical energies remain uncertain due to the extremely low cross sections.

Purpose: This work uses a microscopic potential-model approach to construct the ${}^3\mathrm{He}+\alpha$ potential from the $\text{nucleon}+\alpha$ interaction, aiming to describe low-energy elastic scattering and to calculate the astrophysical $S$ factor of the ${}^3\mathrm{He}(\alpha ,\gamma ){}^7\mathrm{Be}$ reaction.

Method: The nucleon-nucleus potential is derived from self-consistent Skyrme Hartree-Fock (HF) calculations extended to the continuum. The ${}^3\mathrm{He}+\alpha$ potential is then obtained by folding the HF potential with the ${}^3\mathrm{He}$ density. A small number of scaling parameters is constrained by elastic-scattering data.

Result: The scaled Skyrme HF potential and folded potential simultaneously reproduce the low-energy $p+\alpha$ and ${}^3\mathrm{He}+\alpha s$-wave phase shifts, respectively. The calculated astrophysical $S$ factor of ${}^3\mathrm{He}(\alpha ,\gamma ){}^7\mathrm{Be}$ shows good agreement with experimental data, yielding the recommended value $S_{34}\left(0\right)=0.610\pm 0.024$ keV b. A moderate sensitivity of $S_{34}\left(0\right)$ to the choice of projectile density is also observed in the folding procedure.

Conclusion: The Skyrme HF-based potential provides a unified and predictive microscopic framework for describing both elastic scattering and radiative capture in light nuclei.

This paper reports on high-precision measurements of terbium half-lives and cross-section data using $\alpha$ beams on natural europium targets. Energy uncertainties have been minimized through accurate measurement of the $\alpha$-beam energy and high-precision cross sections obtained by a combination of foil thickness characterization, two independent measurement and acquisition systems, and careful monitoring of the irradiated foils over at least four weeks. This has resulted in the most precise cross-section data to-date for natural europium targets with $\alpha$ beams in the 25–40 MeV range. talys-2.0 calculations have been performed, and comparisons made with other available cross-section data, with good agreement attained. Half-lives with increased precision for ${}^{152}\mathrm{Tb}\left(\text{g.s.}\right)$, ${}^{152}\mathrm{Tb}^{m1}\left(\text{g.s.}\right), {}^{153}\mathrm{Tb}\left(\text{g.s.}\right), {}^{154}\mathrm{Tb}^{m1}, {}^{154}\mathrm{Tb}^{m2}$, and ${}^{155}\mathrm{Tb}\left(\text{g.s.}\right)$ are reported.

Recent experimental studies on proton-rich nuclei in the $sd$ shell have revealed intriguing near-threshold phenomena, including exotic structures associated with mirror symmetry breaking. In particular, a halolike structure has been suggested for the $1^{+}$ state of ${}^{22}\mathrm{Al}$ based on the large isospin asymmetry observed in the ${}^{22}\mathrm{Si}/{}^{22}\mathrm{O}$ mirror Gamow-Teller transitions. Recent mass measurements further indicate that the ground state of ${}^{22}\mathrm{Al}$ is weakly bound, with a single-proton separation energy of about 100 keV. To investigate how the continuum affects the structure and decay properties of this proton-dripline nucleus, we employ the state-of-the-art Gamow shell model. This approach utilizes valence-space effective interactions and operators derived from chiral forces. Our calculations identify the ground state of ${}^{22}\mathrm{Al}$ as a $4^{+}$ state, with a $3^{+}$ state as the first excitation. Despite their diffuse nature under weak binding, the Thomas-Ehrman shift for these states is found to be negligible due to their small $s$-wave components. In contrast, the excited $1_1^{+}$ state possesses a significantly larger $s$-wave component, resulting in a more pronounced halolike structure.

Background: The low-lying level structure of ${}^{13}\mathrm{Be}$ is still not fully understood; specifically, it has not been ruled out that the first $1/2^{-}$ state could be located above the isomeric $0_2^{+}$ state of ${}^{12}\mathrm{Be}$ and decay via that state.

Purpose: Search for a possible decay path of ${}^{13}\mathrm{Be}$ excited states through the isomeric $0_2^{+}$ state in ${}^{12}\mathrm{Be}$.

Method: The invariant mass technique was used to reconstruct (${}^{12}\mathrm{Be} +$ n) decay energies from neutron removal reactions of ${}^{14}\mathrm{Be}$ at 78 MeV/u on a ${}^9\mathrm{Be}$ target in coincidence with delayed $\gamma$ rays. Charged particles and neutrons were detected and identified with a telescope and a subset of the Modular Neutron Array (MoNA), respectively, around zero degrees. The CAESium-iodide scintillator ARray (CAESAR) was located around the telescope measuring the $\gamma$ rays.

Results: No evidence for the population and decay of the $0_2^{+}$ state in ${}^{12}\mathrm{Be}$ was observed. From the nonobservation of 511 keV $\gamma$ rays an upper limit of 6% of the $p$-wave contribution was extracted.

Conclusions: The previously observed $p$-wave resonance at about 500 keV does not decay via the isomeric state and thus corresponds to the ground state of ${}^{13}\mathrm{Be}$ decaying to the ${}^{12}\mathrm{Be}$ ground state.

A new model based on the relativistic Boltzmann equation in the isotropization time approximation is developed to investigate the collective behavior of the quark-gluon plasma produced in high-energy heavy-ion collisions. The equation is solved in $(2+2)\mathrm{D}$ (two spatial and two momentum-space dimensions). This framework couples preequilibrium dynamics with hydrodynamic evolution to simulate the dynamics of quasiparticle evolution. A numerical scheme based on the method of characteristics enables the evolution to begin from a specified initial Boltzmann distribution. In this work, the spatial structure of the initial distribution is modeled using the Trento framework. Our results show that a medium initialized at ${\tau }_0$ on the order of $1\mathrm{fm}/c$ with a small shear viscosity to entropy density ratio ($\eta /s=0.008$) evolves consistently with hydrodynamic simulations, such as those performed using the vish2+1 code, while discrepancies arise for a medium with $\eta /s=0.8$. Furthermore, when initialized with a highly anisotropic momentum distribution in the longitudinal direction at early times, the system exhibits spatially nonuniform thermalization in the transverse plane, leading to the emergence of a nontrivial hypersurface that marks the onset of hydrodynamic applicability. Finally, we compute the $p_T$-spectra for a nonfluctuating initial condition using the hybrid version of CoMBolt-ITA. In this hybrid setup, the description is switched from quasiparticles to hadrons, and UrQMD is used to model the hadron gas dynamics. We compare these results with those obtained from the hybrid vish2+1 initialized within the same setup. For a small shear viscosity, $\eta /s=0.08$, the two results show a good level of consistency, whereas for a larger value, $\eta /s=0.8$, a noticeable discrepancy emerges.

We give an analytical expression for the in-plane polarization $P^x$ in heavy-ion collisions that has, to our knowledge, not been measured in heavy-ion collision experiments. We also carry out a numerical study of $P^x$ using a hydrodynamic-model simulation as a cross check for the analytical formula. It is found that if the temperature-gradient contribution is neglected the simulation result for $P^x$ qualitatively agrees with the analytical one. The prediction of $P^x$ can be tested in experiments and will contribute to provide a complete and consistent picture of spin phenomena in heavy-ion collisions.

Lattice QCD calculations have shown that the transition from hadrons to quarks and gluons is a rapid crossover at $T=155–160$ MeV at vanishing chemical potential. Many model calculations show that the transition is first order at a sufficiently high baryon chemical potential. It is then natural to expect the existence of a critical point where the crossover and first-order phase transition lines meet. We show how to embed a phase boundary that terminates at the critical point in a smooth background equation of state, using several different but closely related criteria, so as to yield the critical exponents and critical amplitude ratios expected of a transition in the three-dimensional Ising and liquid-gas universality classes. The crossover curves can be tuned to pass through experimental freeze-out data from heavy-ion collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider. The resulting equations of state can be used in hydrodynamic simulations of these collisions to probe the existence of a critical point and the corresponding first-order phase transition.

In stellar hydrogen burning, the carbon-nitrogen-oxygen (CNO) cycle dominates, with the ${}^{14}\mathrm{N}(p,\gamma ){}^{15}\mathrm{O}$ reaction being the slowest process. Consequently, this reaction critically influences the solar composition, CNO neutrino fluxes, and the evolution of star clusters and galaxies. Recent direct measurements of ${}^{14}\mathrm{N}(p,\gamma ){}^{15}\mathrm{O}$ have reported an enhanced astrophysical $S$ factor. This work presents a microscopic theoretical study of the ${}^{14}\mathrm{N}(p,\gamma ){}^{15}\mathrm{O}$ reaction using the Gamow shell model in the coupled-channels representation. The calculations achieve good agreement with experimental data for both the total $S$ factors and the separate contributions from transitions to the ground state and excited states of ${}^{15}\mathrm{O}$. However, the predicted $S$ factor at zero energy exceeds the experimental value. Based on the computed $S$ factors, the derived carbon and nitrogen abundances align closely with predictions from recent ${}^{14}\mathrm{N}(p,\gamma ){}^{15}\mathrm{O}$ cross-section measurements, yet remain significantly lower than the latest solar neutrino observation values.