We explore the influence of symmetry energy and the $\sigma$-cut potential on the properties of pure nucleonic and hyperon-rich neutron stars employing the relativistic mean-field (RMF) model with the S271 parameter set. The effects of symmetry energy are modulated by the ${\mathrm{\Lambda }}_v$ coupling, while the $\sigma$-cut potential is governed by the free parameter $f_s$. The coupling constants between hyperons and mesons are ascertained based on the most recent hyperon-nucleon potentials derived from existing experimental data. Our analysis suggests that ${\mathrm{\Lambda }}_v$ has more effect compared to $f_s$ on the composition and global properties of neutron stars. Our results are consistent with various observational data, particularly with the GW170817 data.

Four-body systems are studied using an effective-field theory with two- and three-body contact interactions. A method to systematically address deep trimers (three-body bound states that are more tightly bound than four-body bound or resonant states) in four-body calculations is developed using a diagrammatic approach. Previous calculations were limited by the existence of deep trimers, which this work overcomes. For cold ${}^4\mathrm{He}$ atoms, binding energies of 526.1(5) and 128.517(1) mK are obtained at leading order for the tetramer ground and excited states, respectively, where errors come from the truncation of three-body partial waves. Tetramer binding energies and decay widths are also computed approaching the unitary limit. In the unitary limit, there are two tetramers associated with each trimer of binding energy $B_3^{\left(0\right)}$. The binding energy and decay width for the associated tetramer ground state are $E_4^{\left(0\right)}=4.60\left(1\right)B_3^{\left(0\right)}$ and ${\mathrm{\Gamma }}_4^{\left(0\right)}/2=0.0160\left(1\right)B_3^{\left(0\right)}$, respectively, and for the associated tetramer excited state, $E_4^{\left(1\right)}=1.0022\left(3\right)B_3^{\left(0\right)}$ and ${\mathrm{\Gamma }}_4^{\left(1\right)}/2=2.57\left(2\right)\times {10}^{-4}{B}_3^{\left(0\right)}$, respectively. This calculation is a gateway to higher-order and/or more-body calculations in nuclear and atomic systems.

The peculiarities of descent of the nucleus from the fission barrier are investigated within the generalized Langevin equation with the power-law memory function $f(t-t^{\prime })=\left(\right|t-t^{\prime }{|/\tau )}^{-\alpha }$. It is observed that there is much stronger slowing down of the descent in the presence of long-range memory effects, caused by the power-law memory function at $0<\alpha <1$, than of short-range memory effects, generated by the exponential memory function $f(t-t^{\prime })=exp(-|t-t^{\prime }|/\tau )$. At a specific value of the exponent $\alpha =1/2$ of the power-law memory function, it becomes possible to find analytically the trajectory of descent and demonstrate that the long-range memory effects give rise to complex time oscillations of nuclear shape. One found fairly long $(>{10}^{-20}\mathrm{s})$ times of descent of ${}^{236}\mathrm{U}$ at the correlation times $\tau \in [{10}^{-24},{10}^{-22}]\mathrm{s}$.

The evaporation residue (ER) cross sections of $3n$ and $4n$ channels related to the synthesis of a superheavy element (SHE) with the charge number $Z=119$ in the ${}^{51}\mathrm{V}+{}^{248}\mathrm{Cm}$ reaction have been calculated by the dinuclear system (DNS) model as a sum of the partial cross sections of the corresponding channels. The angular momentum distribution of the compound nucleus (CN) is estimated by the dynamical trajectory calculations of the capture probability, which is considered as the DNS formation probability. The fusion probability decreases by the increase of the DNS angular momentum due to its influence on the intrinsic fusion barrier $B_{\mathrm{fus}}^{*}$. The range ${\alpha }_2={60}^{\circ }$–${70}^{\circ }$ of the orientation angle of the axial symmetry axis of the deformed target nucleus ${}^{248}\mathrm{Cm}$ is favorable for the formation of the CN. The fusion probability decreases at around ${\alpha }_2={90}^{\circ }$ since the number of the partial waves contributing to the capture decreases. Therefore, it is important to calculate the capture cross section dynamically. The $4n$ channel cross section of the SHE synthesis is larger than the $3n$ channel cross section maximum value of the ER cross section and it is 12.3 fb at $E_{\mathrm{c}.\mathrm{m}.}=232\mathrm{MeV}$.

Heavy quark diffusion and radiation are discussed in an intermediate-momentum regime where finite mass effects can be significant. Diffusion processes are described in the Fokker-Planck approximation for soft momentum transfer, while radiative ones are taken into account by nearly collinear gluon emission from a single scattering in the Boltzmann equation. There are also radiative corrections to the transverse momentum diffusion coefficient, which are $\mathcal{O}\left(g^2\right)$ suppressed more than the leading-order diffusion coefficient but logarithmically enhanced. Numerical results show that the heavy quark distribution function depends on the energy loss mechanism so that the medium modifications by diffusion and radiation are distinguishable. The nuclear modification factor is estimated by employing the heavy quark diffusion coefficient which is constrained by lattice quantum chromodynamics data. The suppression factor exhibits a transition from diffusion at low momentum to radiation at high momentum. The significance of the radiative effects at intermediate momentum depends on the diffusion coefficient and the running coupling constant.

We propose the 3-momentum sphere intersection regularization applied to the one- and two-fermion line integrals at finite temperature and chemical potential. The quark-antiquark polarization function in this new regularization approach is equivalent to the usual 3-momentum regularization, when the absolute value of the external 3-momentum of the polarization is zero. Additionally, it respects the particle-antiparticle symmetry of meson states in the Nambu–Jona-Lasinio (NJL) model for all values of temperature and chemical potential. Without this symmetry, in-medium cross sections calculated in the 3-momentum regularized NJL model are not consistent. To demonstrate the difference between the usual 3-momentum regularization with the one proposed in this work, we study the quark-quark and quark-antiquark cross sections in both regularization schemes. To this end we use the standard $\text{SU}\left(3\right)$ NJL model, with four- and six-quark interactions. We observe major quantitative and qualitative differences when comparing quark-quark cross sections in both schemes. The quark-antiquark cross sections, on the other hand, are very similar in both regularizations, owning to the equivalence between the regularizations when the absolute value of the external 3-momentum is zero.

We present calculations of the ${}^{40}\mathrm{Ca}$ transverse response function obtained from coupled-cluster theory used in conjunction with the Lorentz integral transform method. We employ nuclear forces derived at next-to-next-to leading order in chiral effective field theory with and without $\mathrm{\Delta }$ degrees of freedom. We first benchmark this approach on the ${}^4\mathrm{He}$ nucleus and compare both the transverse sum rule and the response function to earlier calculations based on different methods. As expected from the power counting of the chiral expansion of electromagnetic currents and from previous studies, our results retaining only one-body term underestimate the experimental data for ${}^4\mathrm{He}$ by about $20\%$. However, when the method is applied to ${}^{40}\mathrm{Ca}$ at the same order of the expansion, response functions do not lack strength and agree well with the world electron scattering data. We discuss various sources of theoretical uncertainties and comment on the comparison of our results with the available experiments.

First-chance fission probabilities $\left(P_{f1}\right)$ of various Am, Pu, and Np isotopes are found to display a significant neutron odd-even stagger (OES), and an obvious excitation energy dependence of the OES is presented. Moreover, a prominent dissipation effect on the OES is revealed, and the differences in $P_{f1}$ of two neighboring fissioning isotopes ${}^{231}\mathrm{Am}$ and ${}^{232}\mathrm{Am}$, ${}^{230}\mathrm{Pu}$ and ${}^{231}\mathrm{Pu}$, and ${}^{225}\mathrm{Np}$ and ${}^{226}\mathrm{Np}$, $\mathrm{\Delta }{P}_{f1}$ (which denotes the amplitude of the OES), are shown to be a quick decreasing function of the dissipation strength $\left(\beta \right)$. This means that the amplitude of the OES is a sensitive experimental indicator of nuclear dissipation properties, and it is proposed here as a new experimental signature to constrain $\beta$. Additionally, we find that $P_{f1}$ of ${}^{231,233}\mathrm{Am}$, ${}^{230,232}\mathrm{Pu}$, and ${}^{225,227}\mathrm{Np}$, whose neutron numbers are even, respectively exhibit an apparently greater sensitivity to $\beta$ than that of their neighboring isotopes ${}^{232}\mathrm{Am}$, ${}^{231}\mathrm{Pu}$, and ${}^{226}\mathrm{Np}$, whose neutron numbers are odd. The neutron odd-even effect is shown to be responsible for the marked enhancement in the sensitivity of the former, clearly indicating its strong influence on using $P_{f1}$ to probe $\beta$. These results suggest that on the experimental side, to more stringently constrain nuclear dissipation by measuring first-chance fission probability, it is optimal to produce those heavy fissioning systems with even neutron numbers.

We report the first direct measurement of the nuclear electron-capture (EC) decay $Q$ value of ${}^7\mathrm{Be}\to {}^7\mathrm{Li}$ via high-precision Penning trap mass spectrometry (PTMS). This was performed using the LEBIT Penning trap located at the National Superconducting Cyclotron Laboratory/Facility for Rare Isotope Beams (NSCL/FRIB) using the newly commissioned Batch-Mode Ion-Source (BMIS) to deliver the unstable ${}^7\mathrm{Be}^{+}$ samples. With a measured value of $Q_{EC}=861.963\left(23\right)$ keV, this result is three times more precise than any previous determination of this quantity. This improved precision and accuracy of the ${}^7\mathrm{Be}$ EC decay $Q$ value is critical for ongoing experiments that measure the recoiling nucleus in this system as a signature to search for beyond the Standard Model (BSM) neutrino physics using ${}^7\mathrm{Be}$-doped superconducting sensors. This experiment has extended LEBIT capabilities, using the first low-energy beam delivered by BMIS at FRIB for PTMS, as well as measuring the lightest-mass isotopes so far with LEBIT.

Medium and high-spin level sequences in ${}^{64}\mathrm{Cu}$ were investigated using the complex ${}^{26}\mathrm{Mg}({}^{48}\mathrm{Ca},\alpha p5n\gamma )$ multinucleon transfer reaction. The experiment was performed at the ATLAS accelerator facility at the Argonne National Laboratory using the Gammasphere array and the fragment mass analyzer (FMA). Two high-spin, quasirotational bands consisting of stretched-$E2$ transitions were observed in coincidence with the known low-spin structure for the first time. These bands share remarkable similarities with highly deformed and/or superdeformed bands observed in the $A\approx 60–70$ mass region. In addition, a regular dipole sequence with weak $E2$ crossover transitions was observed. A general discussion of the observed structures, complemented by theoretical calculations carried out within the framework of the adiabatic and configuration-fixed constrained covariant density functional theory and the quantum particle-rotor model, are presented. The results are interpreted in the context of shell-structure evolution and the collectivity in the mass region.

Background: The equations of state (EoSs) which determine the properties of neutron stars (NSs) are often characterized by the isoscalar and isovector nuclear matter parameters (NMPs). Recent attempts to relate the radius and tidal deformability of a NS to the individual NMPs have been inconclusive. These properties display strong correlations with the pressure of NS matter which depends on several NMPs. It may be necessary to map the NS properties to the NMPs.

Purpose: To identify the important NMPs required to describe the tidal deformability of neutron star for astrophysically relevant range of their gravitational masses (1.2–1.8 ${\mathrm{M}}_{\odot }$) as encountered in the binary neutron star merger events.

Method: We construct a large set of EoSs using four isoscalar and five isovector NMPs. These EoSs are employed to perform a systematic analysis to isolate the NMPs that predominantly determine the tidal deformability parameter obtained by solving the Tolman-Oppenheimer-Volkoff (TOV) equations. The tidal deformability for the EoSs consistent with the chiral effective field theory ($\chi \mathrm{EFT}$) at the lower density and satisfying maximum gravitational mass of stable NS $\ge$ 2 ${\mathrm{M}}_{\odot }$ are directly mapped to these NMPs.

Results: We provide empirical relations between tidal deformability parameter and a minimal set of essential NMPs through lower order polynomial functions. The tidal deformability of the NS with mass 1.2–1.8 ${\mathrm{M}}_{\odot }$ can be determined within 10–30 % directly in terms of linear function of four nuclear matter parameters, namely, the incompressibility coefficient $K_0$ and skewness $Q_0$ of symmetric nuclear matter, and the slope $L_0$ and curvature parameter $K_{\mathrm{sym}0}$ of symmetry energy. The inclusion of the remaining NMPs improves the predictability of tidal deformability to 5–10 %.

Conclusion: Empirical relations are developed for quick estimation of reliable values of tidal deformability, in terms of the NMPs, across a wide range of NS mass for a given EoS model. Our method can also be extended to other NS observables.

High spin states of ${}^{40}\mathrm{K}$ populated through the ${}^{27}\mathrm{Al}({}^{19}\mathrm{F},\alpha np){}^{40}\mathrm{K}$ reaction at 68 MeV beam energy were studied using the Indian National Gamma Array (INGA) facility. Six new levels and fourteen new transitions were added to the existing level scheme. The spins and parities of most of the levels were assigned, modified, or confirmed from $R_{\mathrm{DCO}}$, $R_{\mathrm{ADO}}$, and linear polarization measurements. The multipole mixing ratios $\left(\delta \right)$ for most of the transitions were measured. Large-basis shell-model calculations were performed to understand the microscopic origin of the levels. Different particle restrictions in $sd$ and $pf$ shell orbitals were used to explain the experimental results.

To discuss the half-life of the electron-capture decay of ${}^7\mathrm{Be}$ in cluster and crystal forms of beryllium, we performed density functional calculations of the electron density $\rho \left(0\right)$ at the Be nucleus by assuming an inversely proportional relationship between them. We found that the electron density $\rho \left(0\right)$ decreases with cluster size in Be clusters and increases at an interstitial site in crystalline Be. The electron density $\rho \left(0\right)$ at the hexagonal close packed (HCP) lattice point, i.e., the substitutional site, is about 1.7% smaller than that at the center of ${\mathrm{C}}_{60}$, which perfectly coincides with the recent experimental evidence [Phys. Rev. C 108, L011301 (2023)] that the half-life of ${}^7\mathrm{Be}$ in metallic Be at $T=5\mathrm{K}$ is 1.7% longer than that of ${}^7\mathrm{Be}$@${\mathrm{C}}_{60}$ at $T=5\mathrm{K}$ (i.e., at the center of ${\mathrm{C}}_{60}$). This strongly suggests that at $T=5\mathrm{K}$ all ${}^7\mathrm{Be}$ stay at substitutional sites of the Be metal. For an interstitial Be atom, we found that the basal octahedral (BO) site is energetically most stable, and the basal split (BS) dumbbell structure is second most stable. Performing first-principles MD simulations of a system having an interstitial Be atom at room temperature, we found that (1) in a system having ${}^9\mathrm{Be}$ atoms only, BO can quite rapidly migrate through BS; (2) BS made of ${}^7\mathrm{Be}$ and ${}^9\mathrm{Be}$ atoms very rapidly changes into BO of ${}^7\mathrm{Be}$; and (3) ${}^7\mathrm{Be}$ stays very stably at a BO site and seldom changes its position. Therefore, ${}^7\mathrm{Be}$ stays more likely at BO than ${}^9\mathrm{Be}$ at room temperature. The electron density $\rho \left(0\right)$ at BO is 0.54% higher than $\rho \left(0\right)$ at a substitutional site, which is about double the experimental difference of 0.26% in the half-life of ${}^7\mathrm{Be}$ in Be metal between $T=293\mathrm{K}$ and $T=5\mathrm{K}$. This means that half of ${}^7\mathrm{Be}$ atoms are at BO sites, but the other half still remain at substitutional sites at $T=293\mathrm{K}$. So, we expect that the half-life of ${}^7\mathrm{Be}$ can be further shortened at higher temperatures. Performing unit cell relaxation of a Be crystal, we found that the difference in the total energy between BO and BS is only 0.03 eV. Thus, if there is no ${}^7\mathrm{Be}$, BO can very easily migrate throughout the crystal through the BO $\to$ BS $\to$ BO pathway at room temperature.

We systematically explored all conceivable combinations of projectiles and targets through experimental studies, focusing on the synthesis of lanthanides to superheavy nuclei within the atomic number range of $58\le Z\le 117$. Utilizing the dinuclear system model, we evaluated evaporation residue cross sections for each fusion reaction, identified optimal energies associated with larger evaporation residue cross sections. Our study delved into the influence of entrance channel parameters such as mass asymmetry, charge asymmetry, charge product, Coulomb interaction parameter, mean fissility, and fusion barrier height on these optimal energies. Notably, a systematic variation in optimal energies was observed for the Coulomb interaction parameter. Additionally, the deformation parameter exhibited an influence on optimal energies, and pronounced discrepancies were noted in specific fusion reactions such as ${}^{40}\mathrm{Ar}({}^{181}\mathrm{Ta},4n){}^{217}\mathrm{Pa}$, and for the reactions such as ${}^{16}\mathrm{O}({}^{134}\mathrm{Ba},4n){}^{146}\mathrm{Gd}$, ${}^4\mathrm{He}({}^{166}\mathrm{Er},3n){}^{167}\mathrm{Yb}$, and ${}^{48}\mathrm{Ca}({}^{249}\mathrm{Bk},4n){}^{293}\mathrm{Ts}$, when compared to other fusion reactions explored. The empirical formula presented successfully replicates experimental optimal energies for the atomic number range $58\le Z\le 117$. Its straightforward application involves inputting the atomic and mass numbers of the projectile and target nuclei, along with deformation parameters, underscoring its simplicity and effectiveness in predicting optimal energies in diverse fusion reactions. This simplicity underscores the predictive power of the proposed formula, offering a valuable tool for understanding and predicting optimal energies in a wide range of fusion reactions involving lanthanides and superheavy nuclei.

There are three accepted next proton closures beyond the lead atomic number: $Z=114$, 120, and 126. The heaviest one, $Z=126$, is analyzed within its decay process. A binary adapted macroscopic-microscopic method is used to obtain all fission barriers along different decay channels. The whole range of mass asymmetry is calculated for the fragment emission. The deformed two-center shell model is used to obtain the proton and neutron single-particle energy levels. The levels are used as input for the shell correction energy. The binary Yukawa-plus-exponential model leads to calculation of the macroscopic part of the deformation energy. The dynamics is completed with the Werner-Wheeler mass tensor components. The Wentzel-Kramers-Brillouin (WKB) method provides the penetrabilities and therefore the half-lives for all possible decay channels of ${}^{310}126$.

This study investigates the probable heavy-cluster radioactivity from superheavy nuclei with $100\le Z\le 120$ using the modified double-folding formalism by applying the Pauli exclusion principle. To this aim, the half-lives of the most probable cluster radioactivity are investigated by applying the Pauli exclusion principle to the internal energy of the dinuclear system. The results indicated that considering Pauli blocking as a modification term in calculating the double-folding potential leads to more consistent half-lives with the predictions of other theoretical models. Also, the competition between $\alpha$ decay and heavy-cluster radioactivity at the superheavy region is investigated. The obtained results show that the cluster radioactivity can be expected for some superheavy nuclei with $Z=120$.

We investigate the role of inelastic processes in the strongly interacting quark-gluon plasma (sQGP) based on the effective dynamical quasiparticle model (DQPM). In the DQPM the nonperturbative properties of the sQGP at finite temperature $T$ and baryon chemical potential ${\mu }_B$ are described in terms of strongly interacting off-shell partons (quarks and gluons) with dynamically generated spectral functions whose properties are adjusted to reproduce the lattice QCD equation of state for the quark-gluon plasma in thermodynamic equilibrium. For the first time the massive gluon radiation processes from the off-shell quark-quark $(q+q)$ and quark-gluon $(q+g)$ scatterings are calculated explicitly within leading-order Feynman diagrams with effective propagators and vertices from the DQPM without any further approximations. We present the results for the energy and temperature dependencies of the total and differential radiative cross sections and compare them to the corresponding elastic cross sections. We show that our results reproduce the perturbative QCD calculations in the limit of zero masses and widths of quasiparticles. Also we study the μ${}_B$ dependence of the inelastic cross sections. Moreover, we present estimates for the transition rate and relaxation time of radiative versus elastic scatterings in the sQGP.

Momentum correlation functions between $\pi , K$, and $p$ are calculated for several heavy-ion collision systems, namely ${}_5{}^{10}\mathrm{B}+{}_5{}^{10}\mathrm{B}, {}_8{}^{16}\mathrm{O}+{}_8{}^{16}\mathrm{O}, {}_{20}{}^{40}\mathrm{Ca}+{}_{20}{}^{40}\mathrm{Ca}$, and ${}_{79}{}^{197}\mathrm{Au}+{}_{79}{}^{197}\mathrm{Au}$ in central collisions as well as ${}_{79}{}^{197}\mathrm{Au}+{}_{79}{}^{197}\mathrm{Au}$ collision in different centralities at center-of-mass energy $\sqrt{s_{NN}}=39$ GeV within the framework of a multiphase transport model complemented by the Lednický and Lyuboshitz analytical method. The results present the centrality and system-size dependence of the momentum correlation functions among pairs of $\pi , K$, and $p$, from which the emission source-size can be deduced. It is found that the deduced source sizes increase with the decreasing of centrality for Au $+$ Au system or with the increasing of system size in central collisions with different nuclear size. In addition, through the momentum correlation functions of nonidentical particle pairs gated on velocity, the average emission sequence of nonidentical particles can be indicated. The results illustrate that in the small relative momentum region, protons are emitted in average earlier than ${\pi }^{+}$ and $K^{+}$, and $K^{+}$ are emitted averagely earlier than ${\pi }^{+}$. Furthermore, it seems that larger interval of the average emission order among them is exhibited for smaller collision systems. The present study sheds light on the dynamics of light particle emission at RHIC energy.