The present work is devoted to developing the integrated hydrokinetic model (iHKM) for relativistic nucleus-nucleus collisions. While the previous cycle of works on this topic focused on ultrarelativistic collisions at the top RHIC and different LHC energies, the current work addresses relativistic collisions at the lower energies, specifically ranging from approximately 2 to 50 GeV per nucleon pair in the center-of-mass colliding system. In such collisions, the formation times for the initial state of dense matter can be up to three orders of magnitude longer than those in ultrarelativistic collisions. This difference reflects a fundamentally distinct nature and formation process, particularly regarding the possible stages of initial state evolution, including thermalization (which may be only partial at very low collision energies), subsequent hydrodynamic expansion, and the final transition of matter evolution into a hadronic cascade. These stages, which are fully realized in ultrarelativistic reactions, can also occur within the energy range of BES RHIC, albeit with distinct timescales. This publication not only advances the theoretical development of iHKM [referred to, if necessary, as the extended version of integrated hydrokinetic model ($\mathrm{iHKM}e$)], but also provides examples of model applications for calculating observables. A systematic description across a wide range of experimental energies, which is preliminary yet quite satisfactory, for spectra, flow, and femtoscopy, will follow this study.

For the present work, we have used the $\mathrm{HYDJET}++$ model to explore the production of pure multi-strange hadrons in $\mathrm{Pb}+\mathrm{Pb}$ collisions at $\sqrt{s_{NN}}=2.76$ TeV and $\sqrt{s_{NN}}=5.02$ TeV collision energies, respectively. We have performed simulations to investigate transverse momentum ($p_T$) spectra and elliptic flow ($v_2$) for $\varphi$ mesons and $\mathrm{\Omega }$ baryons, and compared the results both with the ALICE experimental data and available model predictions for selected central classes. Furthermore, we have calculated the nuclear modification factors ($R_{AA}$ and $R_{CP}$), which provide a perception of jet quenching phenomena. Hence, our findings enable the study of the energy and system dependence of $\varphi$ and $\mathrm{\Omega }$ hadrons production over a wide range of ultrarelativistic collision energies. We also present the particle ratios ($\mathrm{\Omega }/\varphi$, ${\overline{\mathrm{\Omega }}}^{+}/{\mathrm{\Omega }}^{-}$, $\mathrm{\Omega }/\pi$, and $\varphi /\pi$), offering insights into the strangeness enhancement and chemical properties of the medium at both CERN Large Hadron Collider collision energies. Additionally, we also explore the predictions for the $\mathrm{\Omega }$ baryon in $\mathrm{Pb}+\mathrm{Pb}$ collisions at $\sqrt{s_{NN}}=5.02$ TeV, focusing on $R_{AA}$, $R_{CP}$, and particle ratios within the $\mathrm{HYDJET}++$ framework, offering insights into future measurements and particle dynamics in high-energy heavy-ion collisions.

Recent high-precision ($e,e^{\prime }{K}^{+}$) experiments have observed two prominent bump structures in the ${}_{\mathrm{\Lambda }}^{10}\mathrm{Be}$ spectrum, challenging our understanding of hypernuclear structure and hyperon-nucleon ($YN$) interactions. Motivated by this, we perform a systematic study of ${}_{\mathrm{\Lambda }}^{10}\mathrm{Be}$ using a microscopic cluster model with a state-of-the-art $YN$ interaction, guided via a control neural network (Ctrl.NN). Our calculations reveal several theoretically significant states within the energy domains of the experimental bumps. In the bump $a$ region ($\approx 8.5\mathrm{MeV}$), we find states corresponding to a $p$-wave $\mathrm{\Lambda }$ hyperon coupled to the ${}^9\mathrm{Be}(3/2_1^{-})$ ground state. Their density distributions show the $p$-wave $\mathrm{\Lambda }$ orbit oriented parallel to the two-$\alpha$ cluster axis, indicating a genuine hypernuclear excitation. In the bump $b$ region, a peculiar $0^{+}$ state is identified, featuring an $s$-wave $\mathrm{\Lambda }$ coupled to a contracted ${}^9\mathrm{Be}$ core (in its $1/2_1^{+}$ state). The density analysis confirms a distinct $\sigma$-orbit structure for the ${}^9\mathrm{Be}$ core. This work provides a detailed structural investigation of candidate states for the observed bumps and underscores the need for higher-resolution experiments to resolve these states and further refine our knowledge of $YN$ interactions.

Background: The mechanism underlying asymmetric fission in the preactinide region remains incompletely understood. Recent experimental analyses of correlations between fragment mass and total kinetic energy (TKE) have demonstrated the efficacy of this approach in identifying fission modes.

Purpose: This study aims to characterize the fission modes of ${}^{188}\mathrm{Pt}$ and ${}^{190}\mathrm{Hg}$, which are in the same isotonic chain, and elucidate their origins through macro-microscopic potential energy surface analyses.

Method: The three-dimensional Langevin approach considering nucleus elongation, deformation, and mass asymmetry is applied to simulate fission dynamics, with the incorporation of angular momentum effects. The effects of multichance fission are incorporated using a combined GEF (2024/V1.1) and Langevin model. Fission modes are determined using two-dimensional multi-Gaussian fitting of mass-TKE correlations.

Results: Angular momentum inclusion narrows the fragment mass and TKE distributions in ${}^{190}\mathrm{Hg}$. Calculations reproduce the double-peak structure in ${}^{190}\mathrm{Hg}$ at low excitation energies. Both first-chance and multichance fission calculations exhibit similar characteristic features in the mass distributions. By applying a two-dimensional multi-Gaussian fit to the mass-TKE correlations, the fission modes of both nuclei are identified as two asymmetric standard modes, a symmetric superlong mode, and a symmetric liquid-drop mode. The liquid-drop mode strengthens with increasing excitation energy, while others diminish, consistent with the weakening of microscopic corrections. Comparative analysis of ${}^{187}\mathrm{Ir}, {}^{188}\mathrm{Pt}$, and ${}^{190}\mathrm{Hg}$ reveals stable proton numbers at $Z\approx$ 35 for one asymmetric standard mode. Potential energy surface and single-particle level analyses demonstrate the asymmetric valleys linked to this asymmetric mode originate at small elongations, driven by proton energy gaps at $Z$ = 35 or 36.

Conclusion: The fission of ${}^{188}\mathrm{Pt}$ and ${}^{190}\mathrm{Hg}$ is consistently described by multiple modes, including the asymmetric mode with $Z\approx$ 35-36. The corresponding asymmetric valley on the potential energy surface emerges early in the fission path.

In the present work, O-O collisions at $\sqrt{s_{NN}}=7\mathrm{TeV}$ and $p$-O collisions at $\sqrt{s_{NN}}=9.9\mathrm{TeV}$ are studied using the $\mathrm{PYTHIA8}$/Angantyr model for heavy-ion collisions. The theoretically predicted $\alpha$-cluster structure of oxygen nucleus is implemented in the model to investigate the effect of the initial configuration of the oxygen nucleus on final state observables. The results obtained from the $\alpha$-cluster structure are compared with those obtained from Woods-Saxon nuclear charge density distribution. The Angantyr model simulation showed that the radial distribution of the oxygen nucleus in $\alpha$-cluster configuration is more compact in comparison to the Woods-Saxon distribution. The results on charged and identified particle pseudorapidity distribution are obtained in the two initial state configurations of the oxygen nucleus. The results demonstrated that the effect of initial geometrical configuration is more distinct in the noncentral collisions in comparison to the central collisions for both O-O and $p$-O collisions.

The interaction potentials, cross sections, and $S$-factors for fusion reactions involving stable and neutron-rich isotopes of C, O, Ne, Mg, and Si, for the neutron star crust, are calculated at subbarrier energies, using a microscopic relativistic energy density functional based on the Dirac-Brueckner-Hartree-Fock (DBHF) approach for asymmetric nuclear matter, employing the Bonn potential A for the nucleon-nucleon interaction. This volume energy density of nuclear matter is supplemented by Coulomb energy and by conventional phenomenological surface energy terms. Calculations using Skyrme, M3Y, and São Paulo (SP) potentials are presented for comparison. Self-consistent proton and neutron densities are used in the calculations of the interaction potentials. Coupled-channels (CC) calculations are considered through the ccfull code. The fusion cross sections and $S$-factors calculated with DBHF potentials are found to be in excellent agreement with experimental data for the systems ${}^{16}\mathrm{O}+{}^{16,18}\mathrm{O}$, ${}^{12}\mathrm{C}+{}^{16,18}\mathrm{O}$, and ${}^{28}\mathrm{Si}+{}^{28,30}\mathrm{Si}$. Hindrance is naturally predicted by the DBHF potentials for medium-heavy systems, such as $\mathrm{Ne}+\mathrm{Ne},\mathrm{Ne}+\mathrm{Mg}$, and $\mathrm{Si}+\mathrm{Si}$. CC calculations, in addition to significantly enhancing the cross section at subbarrier energies, predict measurable shifts in the onset energy of hindrance. The M3Y and SP potentials were unable to describe hindrance, as they produce extremely deep potentials in the overlap region, with no pocket in the surface region. The influence of neutron excess on fusion hindrance is investigated for the neutron-rich systems, ${}^{28}\mathrm{Si}+{}^{30-40}\mathrm{Si}$ and ${}^{40}\mathrm{Si}+{}^{40}\mathrm{Si}$, and an interesting correlation between them has been found. The impact of the equation of state on fusion reactions is investigated, finding significant sensitivity to the symmetry energy and incompressibility of nuclear matter. These results in addition to enhancing our understanding for fusion reactions of stable and neutron-rich isotopes, demonstrate the relativistic DBHF approach as a powerful model for a unified description of nuclear matter, nuclear reactions, and astrophysical environments.

The recent demonstration of laser excitation of the $\approx 8\mathrm{eV}$ isomeric state of ${}^{229}\mathrm{Th}$ is a significant step towards a nuclear clock. The low excitation energy likely results from a cancellation between electromagnetic and strong contributions, which new physics can disrupt. In this Letter, we quantify the enhancement of a nuclear clock's sensitivity to new physics using a geometric model and a novel $d$-wave halo model of the nucleus that reproduces measured differences between ${}^{229}\mathrm{Th}$ states. We find likely enhancements of order ${10}^4$, while a worst case with enhancement $\ll 1$ is unlikely.

We derive a perturbation theory (PT) for the Lorentz boost operator in the space of two-nucleon wave functions. The latter is expressed in terms of the nucleon-nucleon ($NN$) potentials, developed so far in great detail for their use in the $NN$ scattering studies. The PT is designed to take into account the boost relativistic corrections in a systematic way and, as such, it is the only missing part in the corresponding approaches developed up to now in the low-energy effective field theories.

This paper explores momentum-space wave-packet methods to calculate sharp-energy $S$-matrix elements from a time-dependent description of collisions. Two aspects of the computational time-dependent (TD) scattering theory are examined and elucidated: (i) Extraction of the sharp-energy $S$ matrices from the asymptotic analysis of a numerically propagated wave packet, and ii) use of a time-to-energy transform of the numerical wave packet to obtain an energy-resolved time-independent wave packet which provides an alternative form of the asymptotic analysis. The second approach gives rise to a novel expression for the $S$ matrix in terms of time-independent wave packets, which may be useful in the time-independent context as well. In the computational implementation of the methods introduced, the discretization of the spatial variables turns the time-evolution problem of an initial precollision wave packet into a set of first-order differential equations in time. Propagation of the wave packet is then achieved by invoking the central-difference approximation for the time derivative. While time-propagation of the wave packet is carried out, the time-to-energy transform is concurrently accumulated using the trapezoidal rule. These procedures are tested on the $s$-wave scattering problem for a model interaction potential. $S$-matrix elements over a wide range of energies can be extracted from a single wave packet. These wave-packet results are in good agreement with the reference results obtained by solving the Lippmann-Schwinger integral equation one energy at a time for large number of energies.

The low-lying energy spectra of even-even tellurium isotopes near midshell have long been interpreted as ‘‘textbook’’ examples of vibrational collective motion. However, in many cases electric-quadrupole observables, which are a particularly sensitive probe of collectivity, remain undetermined. Coulomb-excitation measurements were performed to measure transition strengths connecting the ground and low-excitation states in ${}^{124}\mathrm{Te}$. This isotope lies at a transitional point between collective structure near the neutron midshell and seniority structures near the $N=82$ shell. A transition strength, $B(E2;6_1^{+}\to 4_1^{+})$, of 27(9) W.u. was measured for the $6_1^{+}\to 4_1^{+}$ transition for the first time in this nucleus; this value is significantly below that expected for a spherical vibrator, as well as other collective models. We examine the transition strengths in ${}^{124}\mathrm{Te}$ and its neighbors by comparison with large-basis shell-model calculations and by comparison with general collective model (GCM) fits. A GCM description of ${}^{120}\mathrm{Te}$ agrees with experimental $E2$ transition strengths, but no comparable description of ${}^{124}\mathrm{Te}$ is possible with the GCM. In contrast, there is remarkably good agreement between the $B(E2;6_1^{+}\to 4_1^{+})$ values and shell-model calculations for ${}^{124\text{–}134}\mathrm{Te}$. It appears that, despite approaching midshell, ${}^{124}\mathrm{Te}$ retains a seniority structure for the $6_1^{+}$ level, i.e., a significant $\pi 0g_{7/2}^2$ contribution. This persistence of the shell structure at the $6_1^{+}$ state is in contrast to the $B\left(E2\right)$ values of the lower-excitation $2_1^{+}$ and $4_1^{+}$ states in ${}^{124}\mathrm{Te}$, and neighboring ${}^{120}\mathrm{Te}$ and ${}^{122}\mathrm{Te}$, for which the collectivity becomes enhanced as more neutrons are removed from $N=82$.

The ${}^{12}\mathrm{C}({}^3\mathrm{He},d){}^{13}\mathrm{N}^{*}$ reaction is studied in an experiment with a high-resolution magnetic spectrograph, in coincidence with protons detected in silicon detectors near the target. This allows for the observation of angular correlation patterns between the proton transfer and proton decays from populated unbound resonances. A formalism describing the spin polarization of direct reactions is developed to analyze these correlations, and is verified on the known directionally asymmetric decay distributions arising from parity mixing in the ${}^{13}\mathrm{N}({\frac{3}{2}}^{-},{\frac{5}{2}}^{+})$ doublet. The same formalism is used to study the decays from the continuum-aligned, broad $3/2^{+}$ resonance at 7.9 MeV excitation energy, which arises from superradiant coupling. The observed asymmetric angular correlation patterns are approximately reproduced by adding an “artificial” $3/2^{-}$ resonance with strength equal to that of the reaction formalism. This parity-mixing approach serves as a first approximation to a more advanced reaction model of rapid reaction and decay sequences.

We investigate the cluster structure of ${}^{13}\mathrm{N}$ using a microscopic $\alpha +\alpha +\alpha +p$ four-body cluster model. The calculated spectra reasonably agree with the observed spectra in the low-lying states. We calculate the reduced width amplitudes and spectroscopic factors to investigate the Hoyle-analog state in ${}^{13}\mathrm{N}$. Our calculations show that the $3/2_3^{-}$ state at $E_x=10.8$ MeV is primarily composed of ${}^{12}\mathrm{C}\left(0_2^{+}\right)+\mathit{p}$ and ${}^9\mathrm{B}(3/2^{-})+\alpha$ components. This finding is generally consistent with the newly observed $3/2^{-}$ state at $E_x=11.3$ MeV via the $3\alpha +\mathit{p}$ decay channel. Moreover, considering the calculated root-mean-square radius and isoscalar monopole transition strength, the $3/2_3^{-}$ state emerges as a candidate for the Hoyle-analog state with the ${}^{12}\mathrm{C}\left(0_2^{+}\right)+\mathit{p}$ cluster structure.

A new phenomenological approach is presented for predicting the spontaneous fission half-lives of actinides and superheavy nuclei. A linear correlation is found between the decimal logarithm of the spontaneous fission half-lives ${log}_{10}{T}_{1/2}^{\text{SF}}$ and the energy release $Q_{\alpha }$ of alpha decay for nuclei with the same neutron excess $N-Z$ and atomic numbers in the range $90\le Z\le 102$. This correlation allows us to propose a semiempirical formula for predicting the spontaneous fission half-lives of even-even nuclei, taking into account both the $Q_{\alpha }$ and $N-Z$. The proposed formula is further extended to predict half-lives for odd-$A$, odd-odd nuclei, and nuclei with $Z\ge 103$. A detailed comparison of the predicted half-lives calculated using the microscopic-macroscopic and self-consistent microscopic models and the new semiempirical formula is given. The competition between alpha decay and spontaneous fission is analyzed. The existence of a fundamental relationship between spontaneous fission and alpha-decay processes is discussed.

We extend the pion-nucleus multiple-scattering framework to include detailed second-order rescattering dynamics for nuclei with nonzero isospin. To account for intermediate charge-exchange and nucleon spin-flip effects, we develop a scattering potential that depends on the one- and two-body densities of the target nucleus. We compute one-body densities from coupled-cluster theory and two-body densities within the Hartree-Fock approximation. To estimate theoretical uncertainties, we employ modern nuclear Hamiltonians derived from chiral effective field theory. While the sensitivity to nuclear structure details is mild, second-order corrections are found to be sizable and essential for accurately reproducing differential cross sections measured in ${\pi }^{\pm }\text{−}{}^{48}\mathrm{Ca}$ elastic scattering within the $\mathrm{\Delta }\left(1232\right)$-resonance region.

This work presents a theoretical investigation of the medium modification of jet broadening as an event-shape observable in multijet final states due to jet quenching in high-energy nuclear collisions. The partonic spectrum of $pp$ collisions with next-to-leading order accuracy at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV is provided by the Powheg$+$Pythia8 event generator, and the linear Boltzmann transport model is utilized to investigate the energy loss of fast partons as they traverse through the hot and dense QCD medium. Jet broadening distributions in multijet final states for both $pp$ and PbPb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are calculated. We observe an enhancement at the small jet broadening region while a suppression at the large jet broadening region in PbPb collisions is relative to that in $pp$. This suggests that medium modifications with parton energy loss in the quark-gluon plasma lead to a more concentrated energy flow in all observed multijet events in PbPb reactions. We also demonstrate that the intertwining of two effects, the jet number reduction and the restructured contribution, results in the behavior of nuclear modification of the jet broadening observable in PbPb collisions.

In relativistic high-energy heavy-ion collisions, the chiral magnetic effect (CME) could produce a charge separation in quark gluon plasma (QGP) and remain in the final hadron system during evolution, observed as the correlator $\mathrm{\Delta }\gamma$. This physics procedure could also occur in small collision systems if the CME were to emerge in the QGP droplet. In this paper, we study the effects of QGP droplet evolution on charge separation in small collision systems, based on a multiphase transport model. Our calculations indicate that, with given initial charge separation, the effects of parton level evolution and hadron level evolution weaken the charge separation indeed, but there are still enough signals that could survive to the final hadron system. Furthermore, we found that, the contribution of background to $\mathrm{\Delta }\gamma$ is negligible in small collision systems. So, we propose the small collision system is a good place to check the contribution of the CME.

An experiment on neutron-deficient nuclei in the region of doubly magic ${}^{100}\mathrm{Sn}$ was carried out at the Radioactive Ion Beam Factory (RIBF) at the RIKEN Nishina Center in Japan. $N\approx Z\approx 50$ nuclei were produced following fragmentation of an intense primary ${}^{124}\mathrm{Xe}$ beam and implanted in the Advanced Implantation Detector Array silicon setup for the first study of proton-rich nuclei with this system at RIKEN. Measurements of the $\beta$-delayed proton emitter decay half-lives, branching ratios and proton energy spectra of nuclei in the region of ${}^{100}\mathrm{Sn}$ were performed, with improved precision in many cases. New results for the energy spectrum of ${}^{101}\mathrm{Sn}$ are presented, where a 2.03(5)-MeV peak was observed. These results are compared to shell-model calculations, using the recent precise measurement of the ${}^{101}\mathrm{In}$ proton separation energy are presented.

The neutron content of compound nuclei (CN), formed in low-energy nuclear reactions, manifests itself in the magnitude of the fragment cross sections. These days, the study of the dependence of associated decay channels on the neutron content is an attractive topic due to the worldwide availability of radioactive ion beams. The dynamical cluster-decay model (DCM) is used to analyze the decay of an isotopic chain of CN ${}^{58–61}\mathrm{Cu}^{*}$, formed in the reactions ${}^{35}\mathrm{Cl}+{}^{23–26}\mathrm{Mg}$, respectively, at different center-of-mass energies $E_{\mathrm{c}}.\mathrm{m}.$. The DCM's collective clusterization approach, based on quantum mechanical fragmentation theory, is employed to understand the influence of successive neutron addition on the decay modes of these CN into light particles (LPs; $A\le 4$), intermediate mass fragments (IMFs; with $5\le A\le 20$), and symmetric mass fragments [SMFs; ($A_{\mathrm{CN}}/2)\pm 10$], and the mutual competition between them. We see that adding a neutron changes the potential energy surfaces (PESs), and, consequently, the preformation profiles of the CN change significantly from ${}^{58}\mathrm{Cu}^{*}$ to ${}^{61}\mathrm{Cu}^{*}$. The PESs for all the CN show that LPs remain dominant in the decay process with their highly minimized values at all the angular momentum $\ell$ values, with IMFs following closely, particularly light IMFs (LIMFs; $5\le A\le 12$). The combined results of the preformation and penetration processes yield fusion cross-section values for the given decays of LPs, IMFs, and SMFs. We find that LPs and LIMFs are the most significant decay modes, with the former being chased by the latter consistently with the successive addition of a neutron in CN from ${}^{58}\mathrm{Cu}^{*}$ to ${}^{60}\mathrm{Cu}^{*}$ and superseding it for the compound nucleus ${}^{61}\mathrm{Cu}^{*}$. The DCM-calculated fusion cross sections ${\sigma }_{\mathrm{fus}}^{\mathrm{DCM}}$ are given by the sum of LP cross sections (${\sigma }_{\mathrm{LP}}$) and LIMF cross sections (${\sigma }_{\mathrm{LIMF}}$), which are in good comparison with the given experimental data. It is important to mention here that $\mathrm{\Delta }R$, associated with the barrier-lowering phenomenon, shows a linear relationship with the $E_{\mathrm{c}}.\mathrm{m}.$ values.

The production of ${}^{270,272-279}\mathrm{Sg}$ in multinucleon transfer reactions induced by radioactive beams ${}^{132}\mathrm{Sn}, {}^{134}\mathrm{Te}$, and ${}^{206}\mathrm{Hg}$ on an actinide target of ${}^{252}\mathrm{Cf}$ is investigated using the dinuclear system model incorporated with $\mathrm{GEMINI}++$ code. The isotopic distributions for $Z=97–100$ in the ${}^{48}\mathrm{Ca}+{}^{248}\mathrm{Cm}, {}^{86}\mathrm{Kr}+{}^{248}\mathrm{Cm}$, and ${}^{136}\mathrm{Xe}+{}^{248}\mathrm{Cm}$ reactions, as well as the angular distribution of total fragments for the ${}^{136}\mathrm{Xe}+{}^{209}\mathrm{Bi}$ reaction, are calculated and compared with available experimental data. Compared to other systems, the ${}^{206}\mathrm{Hg}+{}^{252}\mathrm{Cf}$ reaction at $E_{\text{c.m.}}=748$ MeV is the most optimal system for obtaining large production cross sections of Sg isotopes. Nine unknown isotopes of ${}^{270,272-279}\mathrm{Sg}$ are predicted, with the corresponding production cross sections of $20.860\mu \mathrm{b}, 0.623\mu \mathrm{b}$, 135.514 nb, 24.172 nb, 2.254 nb, 538.796 pb, 164.210 pb, 110.742 pb, and 62.276 pb, respectively. A large number of nucleon transfers occurred extensively within the angular-momentum range of $L\le 100\hslash$ and the interaction time range of ${\tau }_{\mathrm{int}}>5\times {10}^{-22}\mathrm{s}$ in the ${}^{206}\mathrm{Hg}+{}^{252}\mathrm{Cf}$ reaction. The predicted angular distribution of the ${}^{270,272-279}\mathrm{Sg}$ isotopes peaks at an angle of approximately ${40}^{\circ }$.