Results of decay spectroscopy on nuclei in the vicinity of the doubly magic ${}^{48}\mathrm{Ni}$ are presented. The measurements were performed with a time projection chamber with optical readout which records tracks of ions and protons in the gaseous volume. Six decays of ${}^{48}\mathrm{Ni}$, including four events of two-proton ground-state radioactivity, were recorded. An advanced reconstruction procedure yielded the $2p$ decay energy for ${}^{48}\mathrm{Ni}$ of $Q_{2p}=1.29\left(4\right)$ MeV. In addition, the energy spectra of $\beta$-delayed protons emitted in the decays of ${}^{44}\mathrm{Cr}$ and ${}^{46}\mathrm{Fe}$, as well as half-lives and branching ratios, were determined. The results were found to be consistent with the previous measurements made with Si detectors. A new proton line in the decay of ${}^{44}\mathrm{Cr}$ corresponding to the decay energy of 760 keV is reported. The first evidence for the $\beta 2p$ decay of ${}^{46}\mathrm{Fe}$, based on one clear event, is shown.

Angular distributions of the differential cross sections for the quasi-elastic scattering from a ${}^{\mathrm{nat}}\mathrm{Pb}$ target by ${}^{10}\mathrm{C}$ at 226 and 256 MeV, by ${}^{11}\mathrm{C}$ at 222 MeV and 226 MeV, and by ${}^{10}\mathrm{B}$ at 173 MeV were measured at the Heavy Ion Research Facility in Lanzhou, Radioactive Ion Beam Line in Lanzhou (HIRFL-RIBLL). Contributions from the inelastic scattering channels to these data are found to be negligibly small with coupled-channel calculations within the angular range covered by this experiment. These data can be well reproduced by optical model calculations with systematic nucleus-nucleus potentials. The reduced total reaction cross sections were compared with other existing data.

The evolution of the nuclear shell structure in the region of the neutron-rich shell-breaking nucleus ${}^{32}\mathrm{Mg}$ has been the subject of considerable interest. We present here the first determination of the overlap of the ground and two first excited states in ${}^{31}\mathrm{Mg}$ with a neutron coupled to the ground state in ${}^{30}\mathrm{Mg}$ based on studies of its isobaric analog resonances in ${}^{31}\mathrm{Al}$. The excitation function for proton resonant elastic scattering on ${}^{30}\mathrm{Mg}$ was measured close to $0^{\circ }$ in the laboratory frame by bombarding a thick polyethylene target with a ${}^{30}\mathrm{Mg}$ beam at an energy of 2.92 MeV/nucleon at the REX-ISOLDE facility at CERN. Three resonances were successfully resolved, and angular momenta and total and proton resonance widths were determined by using $R$-matrix analysis. The deduced spectroscopic factor for the ground state in ${}^{31}\mathrm{Mg}$ is consistent with the shell-model calculation, whereas those for the first and second excited states could not be reproduced. These results show that a drastic change in structure occurs between ${}^{30}\mathrm{Mg}$ and ${}^{31}\mathrm{Mg}$ and that the onset of structural change in this region therefore occurs between these two isotopes.

In this work we study the diffractive photoproduction of $J/\Psi$ in proton-proton, proton-nucleus, and nucleus-nucleus collisions at Large Hadron Collider energies using the color dipole formalism and different models for the forward dipole-target scattering amplitude. Our goal is to estimate the theoretical uncertainty present in the current predictions in the literature. Our results are compared with the experimental data and predictions for higher energies are presented.

Radioactive beams of ${}^{14}\mathrm{O}$ and ${}^{15}\mathrm{O}$ were used to populate the resonant states ${1/2}^{+}$, ${5/2}^{+}$ and $0^{-},1^{-},2^{-}$ in the unbound ${}^{15}\mathrm{F}$ and ${}^{16}\mathrm{F}$ nuclei, respectively, by means of proton elastic scattering reactions in inverse kinematics. Based on their large proton spectroscopic factor values, the resonant states in ${}^{16}\mathrm{F}$ can be viewed as a core of ${}^{14}\mathrm{O}$ plus a proton in the $2s_{1/2}$ or $1d_{5/2}$ shell and a neutron in $1p_{1/2}$. Experimental energies were used to derive the strength of the $2s_{1/2}$-$1p_{1/2}$ and $1d_{5/2}$-$1p_{1/2}$ proton-neutron interactions. It is found that the former changes by 40% compared with the mirror nucleus ${}^{16}\mathrm{N}$, and the latter changes by 10%. This apparent symmetry breaking of the nuclear force between mirror nuclei finds explanation in the role of the large coupling to the continuum for the states built on an $\ell =0$ proton configuration.

A recent high-resolution $\alpha$, X-ray, and $\gamma$-ray coincidence-spectroscopy experiment offered the first glimpse of excitation schemes of isotopes along $\alpha$-decay chains of $Z=115$. To understand these observations and to make predictions about shell structure of superheavy nuclei below ${}^{288}115$, we employ two complementary mean-field models: the self-consistent Skyrme energy density functional approach and the macroscopic-microscopic Nilsson model. We discuss the spectroscopic information carried by the new data. In particular, candidates for the experimentally observed $E1$ transitions in ${}^{276}\mathrm{Mt}$ are proposed. We find that the presence and nature of low-energy $E1$ transitions in well-deformed nuclei around $Z=110,N=168$ strongly depends on the strength of the spin-orbit coupling; hence, it provides an excellent constraint on theoretical models of superheavy nuclei. To clarify competing theoretical scenarios, an experimental search for $E1$ transitions in odd-$A$ systems ${}^{277}\mathrm{Mt}\mathrm{,}{}^{275}\mathrm{Hs}$, and ${}^{277}\mathrm{Ds}$ is strongly recommended.

The effective $\Lambda N$ potentials are derived from one-boson-exchange hyperon-nucleon interaction such as Juelich potentials, Juelich94a (Jul94) and Juelich05 (Jul05), within the relativistic Brueckner-Hartree-Fock theory. The Jul94 effective $\Lambda N$ potential $U_{\Lambda }$ ($p_{\Lambda }$) with $p_{\Lambda }=0$ is $-27.63$ MeV at the nuclear saturation density, which is in good agreement with the observed data, whereas for the Jul05 effective $\Lambda N$ potential, $U_{\Lambda }$ is $-47.85$ MeV, which is bound more than the observed data. We then compare the effective $\Lambda N$ potential energies obtained in nonrelativistic and relativistic frameworks. With the $\Lambda$ momentum $p_{\Lambda }$ increasing, the relativistic effect becomes obvious and provides more repulsive contribution. We also derive the scalar and vector potentials of the $\Lambda$ hyperon from the effective $\Lambda N$ potential in the relativistic framework. With these potentials, the coupling constants between mesons and the $\Lambda$ hyperon are determined for each density in the framework of relativistic mean-field theory. Finally, we calculate the $\Lambda$ single-particle energies of hypernuclei with these density-dependent coupling constants in the relativistic mean-field theory. We find that the single $\Lambda$ binding energies of $\Lambda$ hypernuclei from ${}_{\mathrm{\Lambda }}{}^{16}\mathrm{O}$ to ${}_{\mathrm{\Lambda }}{}^{208}\mathrm{Pb}$ by using the Jul94 potential compare well with the experimental data.

For central collisions of ${}^{40}\mathrm{Ca}+{}^{40}\mathrm{Ca}$ at 35 MeV/nucleon, the density and temperature of a fragmenting source have been evaluated in a self-consistent manner using the ratio of the symmetry energy coefficient relative to the temperature, $a_{\mathrm{sym}}/T$, extracted from the yields of primary isotopes produced in antisymmetrized molecular dynamics (AMD) simulations. The $a_{\mathrm{sym}}/T$ values are extracted from all isotope yields using an improved method based on the modified Fisher model (MFM). The values of $a_{\mathrm{sym}}/T$ obtained, using different interactions with different density dependencies of the symmetry energy term, are correlated with the values of the symmetry energies at the density of fragment formation. Using this correlation, the fragment formation density is found to be $\rho /{\rho }_0=0.67\pm 0.02$. Using the input symmetry energy value for each interaction temperature values are extracted as a function of isotope mass $A$. The extracted temperature values are compared with those evaluated from the fluctuation thermometer with a radial flow correction.

The matter produced in the early stages of heavy ion collisions consists mostly of gluons, and is penetrated by the coherent magnetic field produced by spectator nucleons. The fluctuations of gluonic matter in an external magnetic field couple to real and virtual photons through virtual quark loops. We study the resulting contributions to photon and dilepton production that stem from the fluctuations of the stress tensor $T_{\mu \nu }$ in the background of a coherent magnetic field $\vec{B}$. Our study extends significantly the earlier work [G. Basar, D. E. Kharzeev, and V. Skokov, Phys. Rev. Lett. 109, 202303 (2012)], in which only the fluctuations of the $trace$ of the stress tensor $T_{\mu \mu }$ were considered (the coupling of $T_{\mu \mu }$ to electromagnetic fields is governed by the scale anomaly). In the present paper we derive more general relations using the operator product expansion (OPE). We also extend the previous study to the case of dileptons, which offers the possibility to discriminate between various production mechanisms. Among the phenomena that we study are magneto-sonoluminescence [MSL, the interaction of magnetic field $\vec{B}(x,t)$ with the sound perturbations of the stress tensor $\delta T_{\mu \nu }(x,t)$] and magneto-thermoluminescence [MTL, the interaction of $\vec{B}(x,t)$ with smooth average $\langle T_{\mu \nu }\rangle$]. We calculate the rates of these process and find that they can dominate the photon and dilepton production at early stages of heavy ion collisions. We also point out the characteristic signatures of MSL and MTL that can be used to establish their presence and to diagnose the produced matter.

The predictive power of modern nuclear-mass models is studied. To quantify this property, we compare the description of masses which were not experimentally known at the time of the model adjustment to that of older masses. For the latter, the masses evaluated in 2003 are taken. The masses evaluated in 2012 and not present in the earlier evaluation of 2003 are considered as the new ones. The predictive power is analyzed for ten often-used models of various natures and also for five different regions in the nuclear chart. A strong dependence of predictive power on the model as well as on the considered region of nuclei is observed. No clear correlation between the accuracy of the description of masses by a model and its predictive power is found.

We report a new direct measurement of the transition energy $Q_{EC}$ of the ${}^{23}\mathrm{Mg}$ ${\beta }^{+}$ decay, using the TITAN Penning-trap mass spectrometer. This value is found to agree with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the $Q_{EC}$ value on the statistical rate function $f_v$ from $11\%$ to $0.6\%$, an improvement by a factor of 18. This enables a more robust determination of the corrected $\mathcal{F}t$ value of this mirror transition to the required precision, making possible further test of the Cabibbo-Kobayashi-Maskawa matrix unitarity.

We employ a variational method, in the framework of the Thomas-Fermi approximation, to study the effect of the symmetry energy on the neutron skin thickness and the symmetry energy coefficients of various neutron-rich nuclei. We concentrate our interest on ${}^{208}\mathrm{Pb}$, ${}^{124}\mathrm{Sn}$, ${}^{90}\mathrm{Zr}$, and ${}^{48}\mathrm{Ca}$, although the method can be applied in the totality of medium and heavy neutron-rich nuclei. Our approach has the advantage that the isospin asymmetry function $\alpha \left(r\right)$, which is the key quantity for calculating isovector properties of various nuclei, is directly related to the symmetry energy as a consequence of the variational principle. Moreover, the Coulomb interaction is included in a self-consistent way and its effects can be separated easily from the nucleon-nucleon interaction. We confirm, both qualitatively and quantitatively, the strong dependence of the symmetry energy on the various isovector properties for the relevant nuclei, using possible constraints between the slope and the value of the symmetry energy at the saturation density.

Yrast and near-yrast states in $\text{odd-}A$ ${}^{89}\mathrm{Nb}$ were investigated using the ${}^{65}\mathrm{Cu}({}^{28}\mathrm{Si}$,$2p2n)$ reaction at a beam energy of 105 MeV. The $\gamma \text{-ray}$ coincidence events were recorded with the Indian National Gamma Array spectrometer. About 30 new transitions have been observed extending the level structure of this nucleus up to spin $45/2\hslash$ and excitation energy of 10.5 MeV. Large-scale shell model calculations were performed using the effective interactions JUN45 and jj44b to understand the structure of the observed states. Reasonable agreement between the experimental observation and shell model calculations suggests that no cross-shell excitations are important up to the maximum spin observed in the current experiment.

The total prompt $\gamma$-ray energy distributions for the neutron-induced fission of ${}^{235}\mathrm{U}$ and ${}^{239,241}\mathrm{Pu}$ in the neutron energy range of 0.025 eV – 100 keV and the spontaneous fission of ${}^{252}\mathrm{Cf}$ were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) in coincidence with the detection of fission fragments by a parallel-plate avalanche counter. DANCE is a highly segmented, highly efficient 4$\pi$ $\gamma$-ray calorimeter. Corrections were made to the measured distribution by unfolding the two-dimension spectrum of total $\gamma$-ray energy vs multiplicity using a simulated DANCE response matrix generated with a geometrical model of the detector arrays and validated with the $\gamma$-ray calibration sources. The mean values of the total prompt $\gamma$-ray energy, determined from the unfolded distributions, are $\sim$20% higher than those of early measurements for all the fissile nuclei studied. The implication for the $\gamma$ heating in nuclear reactors is discussed.

Fission fragment (FF) angular distributions for ${}^{6,7}\mathrm{Li}+{}^{235,238}\mathrm{U}$ reactions have been measured at energies near and above the Coulomb barrier. The angle integrated fission cross sections for ${}^6\mathrm{Li}$ induced reactions at sub-barrier energies are found to be higher than ${}^7\mathrm{Li}$ induced reactions possibly due to a larger contribution of breakup or transfer induced fission in cases of the former compared to the latter. The FF anisotropies for ${}^{6,7}\mathrm{Li}+{}^{235}\mathrm{U}$ are found to be slightly smaller than ${}^{6,7}\mathrm{Li}+{}^{238}\mathrm{U}$, manifesting the effect of target spin. The statistical saddle point model predictions underestimate the measured FF anisotropy for all four systems at measured energies. Anisotropy calculation by entrance channel dependent $K$-state distribution model and determination of $\langle {\ell }^2\rangle$ from continuum discretized coupled channels calculations suggest that the above enhancement in experimental anisotropy is due to a combined effect of entrance channel dependent pre-equilibrium fission and projectile breakup induced fission.

The mass dependence of the transverse flow in the reactions of ${}^{40}\mathrm{Ca}+{}^{40}\mathrm{Ca}$ at 35 MeV/nucleon has been determined for emitted isotopes with $Z=1$ to 9. The observed flow is compared with that calculated using a constrained molecular dynamics (CoMD) simulation. With the application of the appropriate experimental filter, the general trend of the experimental mass-dependent flow is well reproduced by the simulation employing an effective interaction corresponding to a soft equation of state $(K=200$ MeV). The CoMD events are further utilized to study the mechanism of generation of the mass-dependent flow. It is found that the mass-dependent flow is generated by the interplay between the thermal and collective motions under a momentum conservation in the fragmenting system. With the help of the collective-thermal-interplay model, the mass-dependent flow scaled by the reduced mass of fragments $A/A_{\mathrm{sys}}$ is found to be almost independent of the size of the system.

Recent STAR data for the directed flow of protons, antiprotons, and charged pions obtained within the beam energy scan program are analyzed within the parton-hadron-string-dynamics (PHSD and HSD) transport models and a 3-fluid hydrodynamics approach. Both versions of the kinetic approach, HSD and PHSD, are used to clarify the role of partonic degrees of freedom. The PHSD results, simulating a partonic phase and its coexistence with a hadronic one, are roughly consistent with data. The hydrodynamic results are obtained for two equations of state (EoS), a pure hadronic EoS and an EoS with a crossover type transition. The latter case is favored by the STAR experimental data. Special attention is paid to the description of antiproton directed flow based on the balance of $p\overline{p}$ annihilation and the inverse processes for $p\overline{p}$ pair creation from multimeson interactions. Generally, the semiqualitative agreement between the measured data and the model results supports the idea of a crossover type of quark-hadron transition that softens the nuclear EoS but shows no indication of a first-order phase transition.

I study the space-time evolution of transverse flow and effective temperatures in the dense parton phase with the string melting version of a multiphase transport model. Parameters of the model are first constrained to reproduce the bulk data on the rapidity density, $p_T$ spectrum, and elliptic flow at low $p_T$ for central and midcentral Au + Au collisions at $200A$ GeV and Pb + Pb collisions at $2760A$ GeV. I then calculate the transverse flow and effective temperatures in volume cells within mid-spacetime-rapidity $\left|\eta \right|<1/2$. I find that the effective temperatures extracted from different variables, which are all evaluated in the rest frame of a volume cell, can be very different; this indicates that the parton system in the model is not in full chemical or thermal equilibrium locally, even after averaging over many events. In particular, the effective temperatures extracted from the parton energy density or number density are often quite different from those extracted from the parton mean $p_T$ or mean energy. For these collisions in general, effective temperatures extracted from the parton energy density or number density are higher than those extracted from the parton mean $p_T$ in the inner part of the overlap volume, while the opposite occurs in the outer part of the overlap volume. I argue that this indicates that the dense parton matter in the inner part of the overlap volume is overpopulated; I also find that all cells with energy density above 1 ${\text{GeV/fm}}^3$ are overpopulated after a couple of fm/$c$.

In dense astrophysical plasmas, neutron capture populates highly excited nuclear states close to the neutron threshold. The impact of additional low-energy nuclear excitations via coupling to the atomic shell on the ability of the so-formed compound nucleus to retain the captured neutron is investigated. We focus on the mechanism of nuclear excitation by electron capture in plasmas characterized by electron fluxes typical for the slow neutron capture process of stellar nucleosynthesis. The small effect of this further excitation on the neutron capture and $\gamma$ decay sequence relevant for nucleosynthesis is quantified and compared to the corresponding effect of an additional low-energy photoexcitation step.

A significant extension of the level scheme for the odd-odd nucleus ${}^{172}\mathrm{Re}$ was accomplished through the use of the Gammasphere spectrometer. States up to a tentative spin assignment of 39 were observed and two new structures were identified. Configuration assignments are proposed based on alignment properties and observed band crossings.