The $\beta$-decay properties of the very neutron-rich nucleus ${}^{85}\mathrm{Ge}$, produced in the proton-induced fission of ${}^{238}\mathrm{U}$, were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The level scheme of ${}_{33}{}^{85}\mathrm{As}_{52}$ populated in ${}^{85}\mathrm{Ge}\beta \gamma$ decay was reconstructed and compared to shell-model calculations. The investigation of the systematics of low-energy levels in $N=52$ isotones together with shell-model analysis allowed us to provide an estimate of the low-energy structure of the more exotic $N=52$ isotone ${}^{81}\mathrm{Cu}$.

Ratios of differential chemical potential values relative to the temperature, $({\mu }_n-{\mu }_p)/T$, extracted from isotope yields of 13 reaction systems at 40 MeV/nucleon are compared to those of a quantum statistical model to determine the temperature and symmetry energy values of the fragmenting system. The experimental $({\mu }_n-{\mu }_p)/T$ values are extracted based on the modified Fisher model. Using the density value of $\rho /{\rho }_0=0.56$ from the previous analysis, the temperature and symmetry energy values of $T=4.6\pm 0.4$ MeV and $a_{\mathrm{sym}}=23.6\pm 2.1$ MeV are extracted in a framework of a quantum statistical model. These values agree well with those of the previous work, in which a self-consistent method was utilized with antisymmetrized molecular dynamics simulations. The extracted temperature and symmetry energies are discussed together with other experimental values published in literature.

During a carbon therapy treatment, the beam undergoes inelastic nuclear reactions leading to the production of secondary fragments. These nuclear interactions tend to delocate a part of the dose into healthy tissues and create a mixed radiation field. In order to accurately estimate the dose deposited into the tissues, the production rate of these fragments all along the beam path have to be taken into account. But the double differential carbon fragmentation cross sections are not well known in the energy range needed for a treatment (up to 400 MeV/nucleon). Therefore, a series of experiments aiming to measure the double differential fragmentation cross sections of carbon on thin targets of medical interest has been started by our collaboration. In March 2015 we performed an experiment to study the fragmentation of a 50 MeV/nucleon ${}^{12}\mathrm{C}$ beam on thin targets at GANIL. During this experiment, energy and angular cross-section distributions on H, C, O, Al, and ${}^{\mathrm{nat}}\mathrm{Ti}$ have been measured. The experimental set-up will be detailed as well as the systematic error study and all the experimental results will be presented.

Within the framework of the dynamical cluster-decay model (DCM), we have studied the nuclear system with $Z=122$ and mass number $A$ = 306 formed via two “hot” fusion reactions ${}^{58}\mathrm{Fe}+{}^{248}\mathrm{Cm}$ and ${}^{64}\mathrm{Ni}+{}^{242}\mathrm{Pu}$. The up-to-date measured data are available only for the first reaction, and for fusion-fission cross section ${\sigma }_{\mathrm{ff}}$ and quasifission cross section ${\sigma }_{\mathrm{qf}}$, only at one compound nucleus (CN) excitation energy $E^{*}=33\mathrm{MeV}$. In this study, we have included the deformation effects up to quadrupole deformations ${\beta }_{2i}$ and with “optimum” orientations ${\theta }_i^{\mathrm{opt}.}$ for coplanar ($\mathrm{\Phi }=0^0$) configurations. The only parameter of the model is the neck-length parameter $\mathrm{\Delta }R$ whose value, for the nuclear proximity potential used here, remains within its range of validity ($\sim 2\mathrm{fm}$). Using the best fitted $\mathrm{\Delta }R$'s to the observed data for ${\sigma }_{\mathrm{ff}}$, calculated for mass region $A/2\pm 20$, and ${\sigma }_{\mathrm{qf}}$ for the incoming channel of Fe-induced reaction at $E^{*}=33\mathrm{MeV}$, we have extended the DCM calculations to the other Ni-induced reaction, and to $E^{*}$'s in the energy range 25–68 MeV. The interesting result is that the predicted evaporation residue cross section ${\sigma }_{\mathrm{ER}}$ for 1–4 neutrons is largest for 4n decay at $E^{*}=45\mathrm{MeV}$, having the value ${\sigma }_{\mathrm{ER}}\equiv {\sigma }_{4n}\sim {10}^{-5}$ pb for both reactions, and that the $\mathrm{\Delta }R$'s for the three processes (ER, ff, and qf) are different, i.e., they belong to different time scales where ff occurs first, then qf and the ER at the end. Other results of interest are the predictions of the magic $N=82{}^{136}\mathrm{Xe}$ fragment in the ff region of mass $A/2\pm 20$, and the doubly magic ${}^{208}\mathrm{Pb}$ in the qf region, in near close agreement with observed data (the observed fission fragment is of mass 132, instead of the predicted mass 136). The role of the weakly bound neutron-rich intermediate mass fragments and of the nucleus in the neighborhood of deformed magic $Z$ = 108 are also indicated in the DCM calculations, which need experimental verification. For the predicted ${\sigma }_{\mathrm{ER}}$, the largest value of CN fusion probability $P_{\mathrm{CN}}=0.2$, and its survival probability against fission $P_{\mathrm{surv}}\to 0$. Further experiments are called for.

Determination of the baryon number (or mass) distribution of the strangelets, which may fragment out of the warm and excited strange quark matter tidally ejected in the merger of strange stars in the compact binary stellar systems in the galaxy, is attempted here using a statistical disassembly model. Finite mass of strange quarks is taken into account in the analysis. Resulting charges of the strangelets and the corresponding Coulomb corrections are included to get a plausible size distribution of those strangelets as they are produced in stellar mergers, thus getting injected in the galaxy. From this mass distribution of strangelets at their source, an approximate order of magnitude estimate for their possible flux in the solar neighborhood is attempted by using a simple diffusion model for their propagation in the galaxy. Such theoretical estimate is important in view of the ongoing efforts to detect galactic strangelets by recent satellite-borne experiments.

The self-consistent quasiparticle random-phase approximation (QRPA) approach is formulated in the canonical single-nucleon basis of the relativistic Hatree–Fock–Bogoliubov (RHFB) theory. This approach is applied to study the isobaric analog states (IASs) and Gamow–Teller resonances (GTRs) by taking Sn isotopes as examples. It is found that self-consistent treatment of the particle-particle residual interaction is essential to concentrate the IAS in a single peak for open-shell nuclei and the Coulomb exchange term is very important to predict the IAS energies. For the GTR, the isovector pairing can increase the calculated GTR energy, while the isoscalar pairing has an important influence on the low-lying tail of the Gamow–Teller transition.

Self-consistent approaches to superfluid many-fermion systems in three dimensions (and their subsequent use in time-dependent studies) require a large number of diagonalizations of very large dimension Hermitian matrices, which results in enormous computational costs. We present an approach based on the shifted conjugate-orthogonal conjugate-gradient (COCG) Krylov method for the evaluation of the Green's function, from which we subsequently extract various densities (particle number, spin, current, kinetic energy, anomalous, etc.) of a nuclear system. The approach eschews the determination of the quasiparticle wave functions and their corresponding quasiparticle energies, which never explicitly appear in the construction of a single-particle Hamiltonian or needed for the calculation of various static nuclear properties, which depend only on densities. As benchmarks we present calculations for nuclei with axial symmetry, including the ground state of spherical (magic or semimagic) and axially deformed nuclei, the saddle point in the ${}^{240}\mathrm{Pu}$ constrained fission path, and a vortex in the neutron star crust, and demonstrate the superior efficiency of the shifted COCG Krylov method over traditional approaches.

$\alpha$ decay is a common and important process of natural radioactivity of the heavy and superheavy nuclei. From the $\alpha$ decay of nuclei, we can obtain much more information of nuclei structure. In our previous works [X.-D. Sun et al., Phys. Rev. C 93, 034316 (2016); X.-D. Sun et al., Phys. Rev. C 95, 014319 (2017)], we have done systematic study on the $\alpha$ preformation probability of both the even-even and odd-$A$ nuclei within the two-potential approach. The $\alpha$ preformation probabilities will systematically change due to the shell effect, proton-neutron correlation, and so on. This work is the extension of the previous works. In this work, we systematically study the $\alpha$ decay of doubly odd nuclei. We find that for superallowed $\alpha$ decay the $\alpha$ preformation probabilities of doubly odd nuclei are larger than those of odd-$A$ ones in general, and for the heavier nuclei the extra neutrons suppress the proton-neutron correlation resulting in the small $\alpha$ preformation probabilities. The calculated results can well reproduce the experimental half-lives. The half-lives of the $\alpha$ decay chain beginning from nuclide ${}^{296}119$ are also predicted and compared with various empirical formulas.

Event-by-event fluctuations caused by quantum mechanical fluctuations in the wave function of colliding nuclei in ultrarelativistic heavy ion collisions were recently shown to be necessary for the simultaneous description of $R_{\text{AA}}$ as well as the elliptic and triangular flow harmonics at high $p_T$ in PbPb collisions at the Large Hadron Collider (LHC). In fact, the presence of a finite triangular flow as well as cumulants of the flow harmonic distribution that differ from the mean are only possible when these event-by-event fluctuations are considered. In this paper we combine event-by-event viscous hydrodynamics and jet quenching to make predictions for high $p_T{R}_{\text{AA}}, v_2\left\{2\right\}, v_3\left\{2\right\}$, and $v_2\left\{4\right\}$ in PbPb collisions at $\sqrt{s_{NN}}=5.02$ TeV. With an order of magnitude larger statistics we find that high $p_T$ elliptic flow does not scale linearly with the soft elliptical flow, as originally thought, but has deviations from perfectly linear scaling. A new experimental observable, which involves the difference between the ratio of harmonic flow cumulants at high and low $p_T$, is proposed to investigate the fluctuations of high $p_T$ flow harmonics and measure this nonlinear response. By varying the path length dependence of the energy loss and the viscosity of the evolving medium we find that $R_{AA}\left(p_T\right)$ and $v_2\left\{2\right\}\left(p_T\right)$ strongly depend on the choice for the path length dependence of the energy loss, which can be constrained using the new LHC run 2 data.

A general theory of pseudomagnetic effects on the propagation of polarized neutrons through a polarized target using a multiresonance approach is presented. Some applications related to proposed searches for time-reversal invariance violation in neutron scattering are considered.

We apply the proton-neutron deformed quasiparticle random-phase approximation (pn-dQRPA) to describe the low-lying ($E\le 6$ MeV) $1^{+}$ Gamow-Teller (GT) strength functions in odd-odd deformed nuclei which participate as intermediate nuclei in two-neutrino double-$\beta$-decay ($2\nu \beta \beta$) transitions within the mass range $A=70\text{–}176$. In deriving equations of motion we use a single-particle basis with projected angular momentum, provided by the diagonalization of a spherical mean field furnished with a quadrupole-quadrupole interaction. The schematic residual Hamiltonian contains pairing and proton-neutron interaction terms in particle-hole (ph) and particle-particle (pp) channels, with constant strengths. By adopting constant particle-hole and particle-particle strengths we are able to describe the positions of the giant GT resonance and the measured half-lives of the $2\nu \beta \beta$ decays over the whole mass range $A=70\text{–}176$. At the same time we obtain a good agreement with the measured low-lying GT ${\beta }^{-}$ strength functions. By using the adopted ph and pp strengths, we predict the half-lives of a number of deformed $2\nu \beta \beta$ emitters and the low-lying GT strength functions of the corresponding odd-odd intermediate nuclei for their possible experimental tests in the future.

The low-lying spectra of ${}^{24,25,26}\mathrm{Ne}$ and the structure of the pygmy dipole resonance (PDR) in ${}^{26}\mathrm{Ne}$ have been theoretically studied by the antisymmetrized molecular dynamics (AMD) and its extended version called shifted-basis AMD. The calculated energy and strength of the PDR reasonably agree with the observation, and the analysis of the wave function shows that the PDR is dominated by neutron excitation coupled to the quadrupole excited core nucleus ${}^{25}\mathrm{Ne}$, which explains the observed unexpected decay of PDR to the excited states of ${}^{25}\mathrm{Ne}$. The large isoscalar component of PDR is also shown and the enhancement of the core excitation in neutron-rich Ne isotopes is conjectured.

An investigation of the $\alpha$ decay of ${}^{147}\mathrm{Sm}$ was performed using an ultra-low-background twin Frisch-grid ionization chamber (TF-GIC). Four natural samarium samples were produced using pulsed laser deposition in ultrahigh vacuum. The abundance of the ${}^{147}\mathrm{Sm}$ isotope was measured using inductively coupled plasma mass spectrometry. A combined half-life value for ${}^{147}\mathrm{Sm}$ of $1.079\left(26\right)\times {10}^{11}$ yr was measured. A search for the $\alpha$ decay into the first excited state of ${}^{143}\mathrm{Nd}$ has been performed using $\gamma$ spectroscopy, resulting in a lower half-life limit of $T_{1/2}>3.1\times {10}^{18}$ yr (at 90% C.L.).

The $\left({}^3\mathrm{He},t\right)$ charge-exchange reaction populating $J^{\pi }=2^{-}$ states has been examined at 420 MeV incident energy for a series of double-$\beta$ decaying nuclei, i.e., ${}^{76}\mathrm{Ge}$, ${}^{82}\mathrm{Se}$, ${}^{96}\mathrm{Zr}$, ${}^{100}\mathrm{Mo}$, ${}^{128}\mathrm{Te}$, ${}^{130}\mathrm{Te}$, and ${}^{136}\mathrm{Xe}$. The measurements were carried out at the Grand Raiden spectrometer of the Research Center for Nuclear Physics at the University Osaka with typical spectral resolution of 30–40 keV. It is found that the charge-exchange reaction leading to $2^{-}$ spin-dipole states is selective to the $\sigma \tau$ part of the interaction much similar to the observed selectivity to Gamow-Teller transitions. In the present case, the $\mathrm{\Delta }L=1$ peak cross sections at finite momentum transfers are used to extract the spin-isospin part of the low-lying transition strength near the Fermi surface (i.e., $E_x\le 5$ MeV). Relative strength values are confronted with various model calculations, i.e., the interacting shell model, the quasiparticle random-phase approximation, and the Fermi surface quasiparticle model. The impact on the nuclear matrix elements for the neutrinoless double-$\beta$ decay is discussed.

The abnormally large diffuseness parameter of the Woods-Saxon (WS) potential in heavy-ion fusion reactions is explained for the first time based on the microscopic dynamics simulations. With the improved quantum molecular dynamic (ImQMD) model, we systematically explore the dynamical processes in the fusion reactions ${}^{12}\mathrm{C}+{}^{92}\mathrm{Zr}$, ${}^{16}\mathrm{O}+{}^{92}\mathrm{Zr}$, ${}^{28}\mathrm{Si}+{}^{92}\mathrm{Zr}$, ${}^{35}\mathrm{Cl}+{}^{92}\mathrm{Zr}$, ${}^{40}\mathrm{Ca}+{}^{46}\mathrm{Ti}$, and ${}^{16}\mathrm{O}+{}^{154}\mathrm{Sm}$. Without introducing any free model parameters or additional assumptions, the microscopic ImQMD model can reproduce the measured fusion cross sections of all selected colliding systems with good accuracy. Due to the dynamical evolutions of the density distributions in the fusion processes, the energy dependence of nucleus-nucleus potential can be clearly observed. Based on the dynamical nucleus-nucleus potential of the ImQMD simulations, we extract the corresponding diffuseness parameters of the WS potential. The obtained values locate in a range between $\mathit{a}=0.83$ and $1.17\mathrm{fm}$ at different incident energies. In addition, the regular decreasing trend for the diffuseness parameter with the increase of the incident energies is also observed.

The direct component of the ${}^{60}\mathrm{Fe}(n,\gamma ){}^{61}\mathrm{Fe}$ cross section was investigated by populating the bound states of the ${}^{61}\mathrm{Fe}$ nucleus through the $(d,p\gamma )$ transfer reaction in inverse kinematics using a radioactive beam of ${}^{60}\mathrm{Fe}$ at $27A$ MeV. The experiment was performed at GANIL using the MUST2 array and an annular double-sided silicon strip detector for the detection of the light charged particle in coincidence with the photons measured in the EXOGAM $\gamma$-ray detectors. For the first time, the spectroscopic factors of the first $3/2^{-}$, $5/2^{-}$, $1/2^{-}$, and $9/2^{+}$ states of ${}^{61}\mathrm{Fe}$ were deduced experimentally from an adiabatic distorted wave approximation analysis of the data. The obtained results show a very good agreement with the shell-model predictions. The calculated direct component of the $(n,\gamma )$ cross section was found negligible and of about 2% of the total, indicating a dominant resonant component.

The thermodynamical instabilities of low densities in the $np$ matter and $npe$ matter are studied within several relativistic nuclear models under some values of magnetic fields. The results are compared between each other and the effects of the symmetry energy slope at saturation density on the instability are investigated. The instability regions can exhibit bands due to the presence of Landau levels for very strong magnetic fields of the order of ${10}^{17}$ G, while for weaker magnetic fields, the bands are replaced by many diffused or scattered pieces. It also shows that the proton fraction in the inner crust of neutron stars may be complex under strong magnetic fields.

The extension of an equation of motion phonon method to odd nuclei is described step by step. Equations of motion are first constructed and solved to generate an orthonormal basis of correlated $n$-phonon states $\left(n=0,1,2,\cdots \right)$, built of constituent Tamm–Dancoff phonons, describing the excitations of a doubly magic core. Analogous equations are then derived within a subspace spanned by a valence particle coupled to the $n$-phonon core states and solved iteratively to yield a basis of correlated orthonormal multiphonon particle-core states. The basis so constructed is used to solve the full eigenvalue problem for the odd system. The formalism does not rely on approximations but lends itself naturally to simplifying assumptions, as illustrated by its application to ${}^{17}\mathrm{O}$ and ${}^{17}\mathrm{F}$. Self-consistent calculations using a chiral Hamiltonian in a space encompassing up to three-phonon basis states generate spectra having a high level density, comparable to that observed experimentally. The spectroscopic properties are investigated at low energy through the calculation of moments, electromagnetic and $\beta$-decay transition strengths, and at intermediate and high energy through the computation of the electric-dipole spectra and pygmy and giant dipole resonance cross sections. The analysis of the particle-phonon composition of the eigenfunctions contributes to clarify the mechanism of excitation of levels and resonances and gives unique insights into their nature.

Excited states in ${}^{106}\mathrm{Pd}$ were studied with the $\left(n,n^{\prime }\gamma \right)$ reaction, and comprehensive information for excitations with spin $\le 6\hslash$ was obtained. The data include level lifetimes in the femtosecond regime, spins and parities, transition multipolarities, and multipole mixing ratios, which allow the determination of reduced transition probabilities. The $E2$ decay strength to the low-lying states is mapped up to $\approx 2.4$ MeV in excitation energy. The structures associated with quadrupole collectivity are elucidated and organized into bands.

We search for effects of tetrahedral deformation ${\beta }_{32}$ over a range of $\sim 3000$ heavy and superheavy nuclei, $82\le Z\le 126$, using a microscopic-macroscopic model based on the deformed Woods-Saxon potential, well tested in the region. We look for the energy minima with a nonzero tetrahedral distortion, both absolute and conditional—with the quadrupole distortion constrained to zero. In order to assure reliability of our results we include the ten most important deformation parameters in the energy minimization. We could not find any cases of stable tetrahedral shapes. The only sizable—up to 0.7 MeV—lowering of the ground state occurs in superheavy nuclei $Z\ge 120$ for $N=173\mathrm{–}188$, as a result of a combined action of two octupole deformations: ${\beta }_{32}$ and ${\beta }_{30}$, in the ratio ${\beta }_{32}/{\beta }_{30}\approx \sqrt{3/5}$. The resulting shapes are moderately oblate, with the superimposed distortion ${\beta }_{33}$ with respect to the oblate axis, which makes the equator of the oblate spheroid slightly triangular. Almost all found conditional minima are excited; a handful of them are degenerate with the axial minima.