It is important to understand the effect of compression on the decay rate of ${}^7\mathrm{Be}$ because of its significance in calculating ${}^7\mathrm{Be}$ decay rate at the solar core and corresponding ${}^8\mathrm{B}$ neutrino flux. We have measured that the decay rate of ${}^7\mathrm{Be}$ is faster in the smaller spatial confinement of Pd lattice compared to the larger spatial confinement of Pb lattice by (0.82 ± 0.16)%, indicating the effect of compression on the decay rate of ${}^7\mathrm{Be}$ ion, because low and similar electron affinities of Pd and Pb cannot produce any observable effect. Similar results were observed earlier by applying high external pressure on ${}^7\mathrm{BeO}$ lattice. The density functional calculations underpredict the increase of ${}^7\mathrm{Be}$ decay rate under compression by a large factor, although they can account for the effect of electron affinity reasonably well. The unexpectedly large increase (∼1%) of ${}^7\mathrm{Be}$ decay rate under compression (25–40 GPa) compared to the state-of-the-art calculations could have implications on the calculated ${}^7\mathrm{Be}$ decay rate at the solar core.

The symmetry energy obtained with the effective Skyrme energy density functional is related to the values of isoscalar effective mass and isovector effective mass, which is also indirectly related to the incompressibility of symmetric nuclear matter. In this work, we analyze the values of symmetry energy and its related nuclear matter parameters in five-dimensional parameter space by describing the heavy ion collision data, such as isospin diffusion data at 35 MeV/u and 50 MeV/u, neutron skin of ${}^{208}\mathrm{Pb}$, and tidal deformability and maximum mass of neutron star. We obtain the parameter sets which can describe the isospin diffusion, neutron skin, tidal deformability, and maximum mass of neutron star, and give the incompressibility $K_0=250.23\pm 20.16$ MeV, symmetry energy coefficient $S_0=31.35\pm 2.08$ MeV, the slope of symmetry energy $L=59.57\pm 10.06$ MeV, isoscalar effective mass $m_s^{*}/m=0.75\pm 0.05$, and quantity related to effective mass splitting $f_I=0.005\pm 0.170$. At two times normal density, the symmetry energy we obtained is in 35–55 MeV. To reduce the large uncertainties of $f_I$, more critical works in heavy ion collisions at different beam energies are needed.

Radiochemical experiments for low-energy solar-neutrino detection have been making headlines by exploiting the isotopes ${}^{37}\mathrm{Cl}$ and ${}^{71}\mathrm{Ga}$. Such a very low-threshold measurement of this type can also be performed using ${}^{205}\mathrm{Tl}$, which has been considered for decades for this purpose. A unique feature of this detector nucleus is the integration in the solar-neutrino flux over ${10}^6$ of years owing to its long-living daughter ${}^{205}\mathrm{Pb}$. In this Rapid Communication, we have calculated for the first time the cross section for the charged-current solar-neutrino scattering off ${}^{205}\mathrm{Tl}$. Taking into account the solar-model-predicted neutrino fluxes and the electron-neutrino survival probabilities, a solar-neutrino capture rate of $62.2\pm 8.6\mathrm{solar}-\mathrm{neutrio}\mathrm{units}$ is determined, a value significantly smaller than in previous estimates.

A new scheme to study the properties of finite nuclei is proposed based on the Dirac-Brueckner-Hartree-Fock (DBHF) approach starting from a realistic nucleon-nucleon interaction. The relativistic structure of the nucleon self-energies in nuclear matter depending on density, momentum, and isospin asymmetry is determined through a subtracted $T$-matrix technique. The scalar and vector potentials in nuclear matter are parametrized and extrapolated around the very low density region to provide the necessary basis for the finite nuclei calculation. The potentials of a single particle in finite nuclei are generated via a local density approximation (LDA). The surface effect of finite nuclei can be taken into account by an improved LDA. The bulk properties of nuclei can be determined in a self-consistent scheme, and the spherical nuclei ${}^{16}\mathrm{O},{}^{40,48}\mathrm{Ca},{}^{90}\mathrm{Zr},{}^{116,132}\mathrm{Sn}$, and ${}^{208}\mathrm{Pb}$ are sampled for validation. The results show that the calculated binding energies are coincident with the experimental data, and the predicted values for radii and spin-orbit splitting of single-particle energies are reasonably described with an underestimation of about 10%. Basic features of finite nuclei in this scheme are consistent with those of more sophisticated DBHF calculations.

In heavy-ion collisions, momentum-dependent pair correlations can be characterized by a principal component analysis (PCA), in which subleading modes are expected to reveal new information on flow fluctuations. However, we find that, as currently measured, these modes can be dominated by multiplicity fluctuations, which serve as an unwanted background. Here, we propose new PCA observables that are robust against multiplicity fluctuations and isolate novel sources of flow fluctuations, thus being suited to provide fresh insight into the initial stages of the system at small length scales.

The phase-space structure of zero-temperature quarkyonic matter is a Fermi sphere of quark matter surrounded by a shell of nucleonic matter. We construct a quasiparticle model of quarkyonic matter based on the constituent quark model, where the quark and nucleon masses are related by $m_Q=m_N/N_c$, and $N_c$ is the number of quark colors. The region of occupied states is for quarks $k_Q<k_F/N_c$ and for nucleons $k_F<k_N<k_F+\mathrm{\Delta }$. We first consider the general problem of quarkyonic matter with hard-core nucleon interactions. We then specialize to a quasiparticle model where the hard-core nucleon interactions are accounted for by an excluded volume. In this model, we show that the nucleonic shell forms past some critical density related to the hard-core size and for large densities becomes a thin shell. We explore the basic features of such a model and argue this model has the semiquantitative behavior needed to describe neutron stars.

Effective single-particle potentials obtained from the established nonrelativistic nuclear energy density functional approach are incorporated into the microscopic-macroscopic method to calculate the ground-state shell corrections, mass excesses, and $Q_{\alpha }$ values for heaviest nuclei. The low-lying one-quasiparticle states are studied in the isotonic chains with neutron numbers $N=175$, 176, and 177. The isomeric states are discussed in the odd isotopes. The possible $\alpha$-decay chains of nuclei ${}^{295}119$ and ${}^{295,297}120$ are analyzed and compared with the available experimental data. The termination of the $\alpha$-decay chains by spontaneous fission is analyzed. The production cross sections are calculated for superheavy nuclei with $112\le Z\le 120$ in the actinide-based complete fusion reactions with projectiles ${}^{48}\mathrm{Ca}, {}^{48,50}\mathrm{Ti}, {}^{54}\mathrm{Cr}, {}^{58}\mathrm{Fe}$, and ${}^{64}\mathrm{Ni}$.

We apply the Gamow shell model to study ${}^{25–31}\mathrm{F}$ isotopes. As both internucleon correlations and continuum coupling are properly treated therein, the structure shape of ${}^{31}\mathrm{F}$ at large distance can be analyzed precisely. For this, one-nucleon densities, root-mean-square radii, and correlation densities are calculated in neutron-rich fluorine isotopes. It is then suggested that ${}^{31}\mathrm{F}$ exhibits a two-neutron halo structure, built from both continuum coupling and nucleon-nucleon correlations.

By focusing on the asymmetric shape of cross section, we analyze pairing effect on the partial wave components of cross section for neutron elastic scattering off stable and unstable nuclei within the Hartree-Fock-Bogoliubov framework. Explicit expressions for Fano parameters $q_{lj}$ and ${\epsilon }_{lj}$ have been derived and pairing effects have been analyzed in terms of these parameters, and the Fano effect was found on the neutron elastic scattering off the stable nucleus in terms of the pairing correlation. The Fano effect appeared as the asymmetric line shape of the cross section caused by small absolute value of $q_{lj}$ due to small pairing effect on the deep-lying hole state of stable nucleus. In the case of unstable nuclei, the large $q_{lj}$ value is expected because of small absolute value of Fermi energy. The quasiparticle resonance with large $q_{lj}$ forms Breit-Wigner-type shape in elastic-scattering cross section.

Background: Production of neutron-rich nuclei is of vital importance to both understanding nuclear structure far from stability and to informing astrophysical models of the rapid neutron capture process (r-process). Multinucleon transfer (MNT) in heavy-ion collisions offers a possibility to produce neutron-rich nuclei far from stability.

Purpose: The ${}^{176}\mathrm{Yb}+{}^{176}\mathrm{Yb}$ reaction has been suggested as a potential candidate to explore the neutron-rich region surrounding the principal fragments. The current study has been conducted with the goal of providing guidance for future experiments wishing to study this (or similar) system.

Methods: Time-dependent Hartree-Fock (TDHF) and its time-dependent random-phase approximation (TDRPA) extension are used to examine both scattering and MNT characteristics in ${}^{176}\mathrm{Yb}+{}^{176}\mathrm{Yb}$. TDRPA calculations are performed to compute fluctuations and correlations of the neutron and proton numbers, allowing for estimates of primary fragment production probabilities.

Results: Both scattering results from TDHF and transfer results from the TDRPA are presented for different energies, orvientations, and impact parameters. In addition to fragment composition, scattering angles and total kinetic energies, as well as correlations between these observables are presented.

Conclusions: ${}^{176}\mathrm{Yb}+{}^{176}\mathrm{Yb}$ appears to be an interesting probe for the midmass neutron-rich region of the chart of nuclides. The predictions of both TDHF and TDRPA are speculative, and will benefit from future experimental results to test the validity of this approach to studying MNT in heavy, symmetric collisions.

We construct a family of equations of state for QCD in the temperature range $30\mathrm{MeV}\le T\le 800\mathrm{MeV}$ and in the chemical potential range $0\le {\mu }_B\le 450\mathrm{MeV}$. These equations of state match available lattice QCD results up to $O\left({\mu }_B^4\right)$ and in each of them we place a critical point in the three-dimensional (3D) Ising model universality class. The position of this critical point can be chosen in the range of chemical potentials covered by the second Beam Energy Scan at the Relativistic Heavy Ion Collider. We discuss possible choices for the free parameters, which arise from mapping the Ising model onto QCD. Our results for the pressure, entropy density, baryon density, energy density, and speed of sound can be used as inputs in the hydrodynamical simulations of the fireball created in heavy ion collisions. We also show our result for the second cumulant of the baryon number in thermal equilibrium, displaying its divergence at the critical point. In the future, comparisons between RHIC data and the output of the hydrodynamic simulations, including calculations of fluctuation observables, built upon the model equations of state that we have constructed may be used to locate the critical point in the QCD phase diagram, if there is one to be found.

We studied the centrality selection effect on cumulants (up to fourth order) and the cumulants' ratios of net-proton multiplicity distributions in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=7.7$, 19.6, and 200 GeV from the ultrarelativistic quantum molecular dynamic model. The net-proton cumulants were calculated with collision centralities by using charged-particle multiplicity from different pesudorapidity ($\eta$) regions. By comparing the results from various collision centralities, we found that the autocorrelation effects are not significant in the results with the collision centralities “refmult-3” and “refmult-2,” which use midrapidity charged particles but exclude (anti)protons and the analysis region, respectively. Furthermore, due to the contributions of spectator protons, we observed poor centrality resolution when using charged particles at forward $\eta$ regions at low energies. This work can serve as a baseline for centrality selection of future fluctuations analysis in relativistic heavy-ion collisions.

Nuclear density functional theory (DFT) plays a prominent role in the understanding of nuclear structure, being the approach with the widest range of applications. Hohenberg and Kohn theorems warrant the existence of a nuclear energy density functional (EDF), yet its form is unknown. Current efforts to build a nuclear EDF are hindered by the lack of a strategy for systematic improvement. In this context, alternative approaches should be pursued and, so far, an unexplored avenue is that related to the inverse DFT problem. DFT is based on the one-to-one correspondence between Kohn-Sham (KS) potentials and densities. The exact EDF produces the exact density, so that from the knowledge of experimental or ab initio densities one may deduce useful information through reverse engineering. The idea has already been proved to be useful in the case of electronic systems. The general problem should be dealt with in steps, and the objective of the present work is to focus on testing algorithms to extract the Kohn-Sham potential within the simplest ansatz from the knowledge of the experimental neutron and proton densities. We conclude that, while robust algorithms exist, the experimental densities present some critical aspects. Finally, we provide some perspectives for future works.

The cluster states in ${}^{13}\mathrm{C}$ are investigated by antisymmetrized molecular dynamics. By investigating the spectroscopic factors, the cluster configurations of the excited states are discussed. It is found that the $1/2_2^{+}$ state is dominantly composed of the ${}^{12}\mathrm{C}\left(0_2^{+}\right)\otimes s_{1/2}$ configuration and can be regarded as a Hoyle-analog state. On the other hand, the $p$-wave states ($3/2^{-}$ and $1/2^{-}$) do not have such structure, because of the coupling with other configurations. The isoscalar monopole and dipole transition strengths from the ground to the excited states are also studied. It is shown that the excited $1/2^{-}$ states have strong isoscalar monopole transition strengths consistent with the observation. On the other hand, the excited $1/2^{+}$ states unexpectedly have weak isoscalar dipole transitions except for the $1/2_1^{+}$ state. It is discussed that the suppression of the dipole transition is attributed to the property of the dipole operator.

Because the traditional observable of charge-dependent azimuthal correlator $\gamma$ contains contributions from both the chiral magnetic effect (CME) and its background, a new observable of $R_{{\mathrm{\Psi }}_m}$ was recently proposed which is expected to be able to distinguish the CME from the background. In this study, we apply two methods to calculate $R_{{\mathrm{\Psi }}_m}$ using a multiphase transport model without or with introduction of a percentage of CME-induced charge separation. Our results show that the shape of final $R_{{\mathrm{\Psi }}_2}$ distribution is flat for the case without the CME, but concave for that with an amount of the CME because the initial CME signal survives from strong final state interactions. By comparing the responses of $R_{{\mathrm{\Psi }}_2}$ and $\gamma$ to the strength of the initial CME signal, we observe that both observables show nonlinear sensitivities to the CME because of the existence of strong final state interactions.

The binomial acceptance correction procedure is studied for particle number distributions detected in high-energy reactions in finite regions of the momentum space. We present acceptance correction formulas for scaled variance, skewness, and kurtosis. Our considerations include various specific types of particles—positively or negatively charged baryons and antibaryons—as well as conserved charges, namely, the net baryon number and electric charge. A simple model with effects of exact charge conservation, namely the Bessel distribution, is studied in some detail where effects of multiparticle correlations are present. The accuracy of the binomial filter is studied with UrQMD model simulations of inelastic proton-proton reactions. The binomial acceptance correction procedure works well when used inside a small region of phase space as well as for certain other types of corrections, in particular for constructing net proton fluctuations from net baryon ones. Its performance is less accurate when applied to obtain UrQMD fluctuations in a finite rapidity window from fluctuations in the full $4\pi$ space.

To test the predictive power of ab initio nuclear structure theory, the lifetime of the second $2^{+}$ state in neutron-rich ${}^{20}\mathrm{O},\tau \left(2_2^{+}\right)={150}_{-30}^{+80}\mathrm{fs}$, and an estimate for the lifetime of the second $2^{+}$ state in ${}^{16}\mathrm{C}$ have been obtained for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds of femtoseconds range by analyzing the Doppler-shifted $\gamma$-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction ${}^{18}\mathrm{O}\left(7.0\mathrm{MeV}/\mathrm{u}\right)+{}^{181}\mathrm{Ta}$. The requested sensitivity could only be reached owing to the excellent performances of the Advanced $\gamma$-Tracking Array AGATA, coupled to the PARIS scintillator array and to the $\mathrm{VAMOS}++$ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for ${}^{20}\mathrm{O}$ and with the no-core shell model for ${}^{16}\mathrm{C}$. The present measurement shows the power of electromagnetic observables, determined with high-precision $\gamma$ spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetime measurements in unexplored regions of the nuclear chart, including $r$-process nuclei, when intense beams, produced by Isotope Separation On-Line (ISOL) techniques, become available.

Relative to their population in a recent investigation of the ${}^9\mathrm{Be}({}^{18}\mathrm{O},{}^{16}\mathrm{O}){}^{11}\mathrm{Be}$ reaction, the first two ${\left(sd\right)}^2$ states of ${}^{11}\mathrm{Be}$ were considerably stronger (by factors of 2–3) in an earlier ${}^9\mathrm{Be}(t,p)$ experiment. Comparison with other results suggests the presence of at least two states near 5.9 MeV, populated with different selectivity in different reactions.

The dynamical mechanism of multinucleon transfer reactions was investigated within the dinuclear system model, in which the sequential nucleon transfer is described by solving a set of microscopically derived master equations. Production cross sections, total kinetic energy spectra, and angular distribution of formed fragments in the reactions of ${}^{124,132}\mathrm{Sn}+$ ${}^{238}\mathrm{U}/{}^{248}\mathrm{Cm}$ near Coulomb barrier energies are thoroughly analyzed. It is found that the total kinetic energies of primary fragments are dissipated from the relative motion energy and rotational energy of the two colliding nuclei. The fragments are formed in the forward angle domain. The energy dependence of the angular spectra is different between projectilelike and targetlike fragments. Isospin equilibrium is governed under the potential energy surface. The production cross sections of neutron-rich isotopes are enhanced around the shell closure.