A segmented Si telescope and HPGe array is used to study the ${}^{156}\mathrm{Gd}$($p,d-\gamma$)${}^{155}\mathrm{Gd}$ direct reaction by $d$-$\gamma$ and $d$-$\gamma$-$\gamma$ coincidence measurements using 25-MeV protons. The present investigation is the first time that this $N=91$ nucleus and the $N=90$ region—which is known for a rapid change from vibrational to rotational character, several low-lying $0^{+}$ states in the even-even nuclei, and large Coriolis ($\Delta \Omega =1$) plus $\Delta N=2$ mixing in the even-odd nuclei—have been studied by particle-$\gamma$ coincidence following a direct reaction with light ions. Gamma-ray energies and branches, excitation energies, angular distributions, and cross sections are measured for states directly populated in the ($p,d$) reaction. A new low-energy doublet state at 592.46 keV (previously associated with the $K=0\otimes {\frac{3}{2}}^{-}[521]$ bandhead) and several new $\gamma$-ray transitions (particularly for states with excitation energies $>1$ MeV) are presented. Most notably, the previous $\nu \hspace{0.5em}{\frac{7}{2}}^{+}[404]$ systematics at and around the $N=90$ transition region are brought into question and reassigned as $\nu \hspace{0.5em}{\frac{5}{2}}^{+}[402]$. This reassignment makes the $\nu \hspace{0.5em}{\frac{1}{2}}^{+}[400]$, $\nu \hspace{0.5em}{\frac{3}{2}}^{+}[402]$, and $\nu \hspace{0.5em}{\frac{5}{2}}^{+}[402]$ orbitals, which originate from the $3s_{1/2}$, $2d_{3/2}$, and $2d_{5/2}$ spherical states, respectively, responsible for the three largest cross sections to positive-parity states in the ($p,d$)${}^{155}\mathrm{Gd}$ direct reaction. These three steeply upsloping orbitals undergo $\Delta N=2$ mixing with their $N=6$ orbital partners, which are oppositely sloped with respect to deformation. The presence of these steeply sloped and crossing orbitals near the Fermi surface could weaken the monopole pairing strength and increase the quadrupole pairing strength of neighboring even-even nuclei, which would bring $\nu \hspace{0.5em}$2p-2h $0^{+}$ states below $2\Delta$. Indeed, this could account for a large number of the low-lying $0^{+}$ states populated in the ($p,t$)${}^{154}\mathrm{Gd}$ direct reaction.

High-spin states ($I\lesssim 50\hslash$) of the odd-odd nucleus ${}^{170}\mathrm{Ta}$ have been investigated with the ${}^{124}\mathrm{Sn}$(${}^{51}\mathrm{V},5n$) reaction. The resolving power of Gammasphere has allowed for the observation of eleven rotational bands (eight of which are new) and over 430 transitions ($~$$350$ of which are new) in this nucleus. Many interband transitions have been observed such that the relative spins and excitation energies of the $11$ bands have been established. This is an unusual circumstance in an odd-odd study. Configurations have been assigned to most of these bands based upon features such as alignment properties, band crossings, $B(M1)/B(E2)$ ratios, and the additivity of Routhians. A systematic study of the frequency at which normal signature ordering occurs in the $\pi h_{9/2}\nu i_{13/2}$ band has been performed and it is found that its trend is opposite to that observed in the $\pi h_{11/2}\nu i_{13/2}$ bands. A possible interpretation of these trends is discussed based on a proton-neutron interaction.

Using the three versions of proximity potentials, namely proximity 1977, proximity 1988, and proximity 2000, we present a pocket formula for fusion barrier heights and positions. This was achieved by analyzing as many as $400$ reactions with mass between $15$ and $296$. Our parametrized formula can reproduced the exact barrier heights and positions within an accuracy of $\pm 1\%$. A comparison with the experimental data is also in good agreement.

Using the different versions of phenomenological proximity potential as well as other parametrizations within the proximity concept, we perform a detailed comparative study of fusion barriers for asymmetric colliding nuclei with asymmetry parameter as high as $0.23$. In all, $12$ different proximity potentials are robust against the experimental data of $60$ reactions. Our detailed study reveals that the surface energy coefficient as well as radius of the colliding nuclei depend significantly on the asymmetry parameter. All models are able to explain the fusion barrier heights within $\pm 10\%$ on the average. The potentials due to Bass $80$, AW $95$, and Denisov DP explain nicely the fusion cross sections at above- as well as below-barrier energies.

Nonidentical-particle femtoscopy probes not only the size of the emitting system, but also the emission asymmetries between particles of different masses, which are intimately related to the collective behavior of matter. We apply the technique to simulations from the therminator $+$ lhyquid model of heavy-ion collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV. We present predictions for all pairwise combinations of pions, kaons, and protons and discuss their interpretation. We show that kaon and proton distributions are strongly influenced by flow: the source gets smaller and shifted to the outside with growing $p_T$, while for pions the shift is significantly smaller, producing an emission asymmetry. We explain how particles coming from decays of hadronic resonances enhance the asymmetry signal coming from flow, contrary to naive expectations. Emphasis is put on extracting this unique information on the collective behavior of matter from nonidentical-particle correlations. We also present, in detail, the technical aspects of the nonidentical-particle femtoscopy technique applied to data from heavy-ion collisions. We list the sources of systematic errors coming from the method itself and the usual assumptions. We describe robust analysis methods and discuss their limitations.

The reaction ${}^3\text{He}+{}^{11}\text{B}\to d+{}^{12}{\text{C}}^{*}$ has been used to populate resonances in ${}^{12}\mathrm{C}$ up to an excitation energy of $15$ MeV. The subsequent breakup to three $\alpha$ particles has been measured in complete kinematics. Dalitz plots are used to visualize and analyze the data. The Dalitz plot intensity distribution exhibits zero points characteristic of the total spin and parity of the $3\alpha$ system allowing us to determine the spin and parity of a state in ${}^{12}\mathrm{C}$ at $13.35$ MeV whose quantum numbers were hitherto not well established. The Dalitz plot intensity distributions of the $2^{-}$ state at $11.83$ MeV and the $1^{+}$ state at $12.71$ MeV are compared with the predictions of a recent three-body calculation as well as with simpler models. All are able to reproduce the gross structures seen in the Dalitz plot, but none give an accurate description of the detailed profile of the distributions.

Gamow-Teller strength distributions, $\beta$-decay half-lives, and $\beta$-delayed neutron emission are investigated in neutron-rich Zr and Mo isotopes within a deformed quasiparticle random-phase approximation. The approach is based on a self-consistent Skyrme Hartree-Fock mean field with pairing correlations and residual separable particle-hole and particle-particle forces. Comparison with recent measurements of half-lives stresses the important role that nuclear deformation plays in the description of $\beta$-decay properties in this mass region.

The contribution of ground-state correlations (GSCs) to the nonmesonic weak decay of ${}_{\Lambda }^{12}\mathrm{C}$ and other medium to heavy hypernuclei is studied within a nuclear-matter formalism implemented in a local-density approximation. We adopt a weak transition potential including the exchange of the complete octets of pseudoscalar and vector mesons, as well as a residual strong interaction modeled on the Bonn potential. Leading GSC contributions, at first order in the residual strong interaction, are introduced on the same footing for all isospin channels of one- and two-nucleon induced decays. Together with fermion antisymmetrization, GSCs turn out to be important for an accurate determination of the decay widths. Besides opening the two-nucleon stimulated decay channels, for ${}_{\Lambda }^{12}\mathrm{C}$ GSCs are responsible for 14% of the rate ${\Gamma }_1$ while increasing the ${\Gamma }_n/{\Gamma }_p$ ratio by $4\%$. Our final results for ${}_{\Lambda }^{12}\mathrm{C}$ are ${\Gamma }_{\mathrm{NM}}=0.98$, ${\Gamma }_n/{\Gamma }_p=0.34$, and ${\Gamma }_2/{\Gamma }_{\mathrm{NM}}=0.26$. The saturation property of ${\Gamma }_{\mathrm{NM}}$ with increasing hypernuclear mass number is clearly observed. The agreement with data of our predictions for ${\Gamma }_{\mathrm{NM}}$, ${\Gamma }_n/{\Gamma }_p$, and ${\Gamma }_2$ is rather good.

We study theoretically the elastic scattering of ${}^8\mathrm{B}$ from ${}^{12}\mathrm{C}$ at $E_{\mathrm{lab}}=95$ MeV. The ${}^8\mathrm{B}$ nucleus consists of weakly bound ${}^7\mathrm{Be}$ and proton, while the ${}^7\mathrm{Be}$ nucleus has an internal cluster structure of $\alpha +{}^3\mathrm{He}$. We treat the last proton in ${}^8\mathrm{B}$ in the adiabatic recoil approximation and also take into account the excitation of ${}^7\mathrm{Be}$ including resonance states by a coupled-channel method with consideration of the cluster structure. It turns out that the excitation to the resonance state of ${}^7\mathrm{Be}$ in ${}^8\mathrm{B}$ is important for the ${}^8\mathrm{B}$ elastic scattering.

The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt allows accurate mass measurements of radionuclides, produced in fusion-evaporation reactions and separated by the velocity filter SHIP from the primary beam. Recently, the masses of the three nobelium isotopes ${}^{252-254}\mathrm{No}$ were determined. These are the first direct mass measurements of transuranium elements, which provide new anchor points in this region. The heavy nuclides were produced in cold-fusion reactions by irradiating a PbS target with a ${}^{48}\mathrm{Ca}$ beam, resulting in production rates of the nuclei of interest of about one atom per second. In combination with data from decay spectroscopy our results are used to perform a new atomic-mass evaluation in this region.

We investigate the entrance channel dynamics for the reactions ${}^{70}\mathrm{Zn}+{}^{208}\mathrm{Pb}$ and ${}^{48}\mathrm{Ca}+{}^{238}\mathrm{U}$ by using the fully microscopic time-dependent Hartree-Fock theory coupled with a density constraint. We calculate excitation energies and capture cross sections relevant for the study of superheavy formations. We discuss the deformation dependence of the ion-ion potential for the ${}^{48}\mathrm{Ca}+{}^{238}\mathrm{U}$ system and perform an alignment angle averaging for the calculation of the capture cross section. The results show that this approach can generate results in good agreement with experiments and other theories.

We derive analytical forms for nonflow contributions from cluster correlation to the measurement of two-particle elliptic flow ($v_2\{2\}$). We estimate nonflow contribution from $\rho \to {\pi }^{+}{\pi }^{-}$ decays and find it is negative but not a major contributor to the nonflow effect in $v_2\{2\}$. We also estimate nonflow contribution from the recent STAR measurement of two-particle angular correlations.

Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out reactions) using radioactive beams are evaluated. Because in most of the cases intensities of radioactive beams are significantly less than those of the stable beams, reactions with the greatest radioactive-beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland [Phys. Rev. C 76, 014612 (2007)], who investigated the same nuclei.

$\alpha +{}^{12}\mathrm{C}$ elastic scattering at low energies is analyzed with the optical model. The $\alpha +{}^{12}\mathrm{C}$ system is transparent over the entire radial range. Weak coupling to other reaction channels seems good enough below $E_{\mathrm{c}.\mathrm{m}.}=5$ MeV.

The influence of $\alpha$ clustering on nuclear reaction dynamics is investigated using the giant dipole resonance (GDR) lineshape studies in the reactions ${}^{20}\mathrm{Ne}$ ($E_{\mathrm{lab}}=145,160$ MeV) $+$ ${}^{12}\mathrm{C}$ and ${}^{20}\mathrm{Ne}$ ($E_{\mathrm{lab}}=160$ MeV) $+$ ${}^{27}\mathrm{Al}$, populating ${}^{32}\mathrm{S}$ and ${}^{47}\mathrm{V}$, respectively. The GDR lineshapes from the two systems are remarkably different from each other. Whereas, the non-$\alpha$-like ${}^{47}\mathrm{V}$ undergoes Jacobi shape transition and matches exceptionally well with the theoretical GDR lineshape estimated under the framework rotating liquid drop model (RLDM) and thermal shape fluctuation model (TSFM) signifying shape equilibration, for the $\alpha$ cluster ${}^{32}\mathrm{S}$ an extended prolate kind of shape is observed. This unusual deformation, seen directly via $\gamma$ decay for the first time, is predicted to be due to the formation of orbiting dinuclear configuration or molecular structure of ${}^{16}\mathrm{O}$ $+$ ${}^{16}\mathrm{O}$ in the ${}^{32}\mathrm{S}$ superdeformed band.

The theory for condensation of higher fermionic clusters is developed. Fully self-consistent nonlinear equations for the quartet order parameter in strongly coupled fermionic systems are established and solved. The breakdown of the quasiparticle picture is pointed out. Derivation of numerically tractable approximation is described. The momentum projected factorization ansatz for the order parameter is employed. As a definite example, the condensation of $\alpha$ particles in nuclear matter is worked out.

The nuclear level densities of ${}^{118,119}\mathrm{Sn}$ and the $\gamma$-ray strength functions of ${}^{116,118,119}\mathrm{Sn}$ below the neutron separation energy are extracted with the Oslo method using the (${}^3\mathrm{He}$,$\alpha \gamma$) and (${}^3\mathrm{He}$,${}^3\mathrm{He}$${}^{\prime }\gamma$) reactions. The level-density function of ${}^{119}\mathrm{Sn}$ displays steplike structures. The microcanonical entropies are deduced from the level densities, and the single neutron entropy of ${}^{119}\mathrm{Sn}$ is determined to be $1.7$ $\pm$ $0.2$ $k_B$. Results from a combinatorial model support the interpretation that some of the low-energy steps in the level density function are caused by neutron pair breaking. An enhancement in all the $\gamma$-ray strength functions of ${}^{116-119}\mathrm{Sn}$, compared to standard models for radiative strength, is observed for the $\gamma$-ray energy region of $\simeq$$4-11$ MeV. These small resonances all have a centroid energy of $8.0(1)$ MeV and an integrated strength corresponding to $1.7(9)\%$ of the classical Thomas-Reiche-Kuhn sum rule. The Sn resonances may be due to electric dipole neutron skin oscillations or to an enhancement of the giant magnetic dipole resonance.

An experimental search for the low-lying ${}^7\mathrm{H}$ resonance was performed with the ${}^2\mathrm{H}$(${}^8\mathrm{He}$${}^3\mathrm{He}$)${}^7\mathrm{H}$ reaction studied at forward center-of-mass angles ($6^{°}$–14${}^{°}$) with a $42\hspace{0.5em}A$ MeV ${}^8\mathrm{He}$ beam. No well-pronounced peak of ${}^7\mathrm{H}$ was observed; however, the obtained spectrum was found to have a peculiarity at $~2$ MeV above the $t+4n$ threshold. The data allow us to set a c.m.s. cross section level of $~$$30$ $\mu$b/sr for the low-energy part of the ${}^7\mathrm{H}$ spectrum. The test reaction ${}^2\mathrm{H}$(${}^{12}\mathrm{Be}$${}^3\mathrm{He}$)${}^{11}\mathrm{Li}$, involving the same one-proton ($d$,${}^3\mathrm{He}$) transfer, was studied simultaneously on a $71$ $A$ MeV satellite beam where a cross section of $\simeq$$1$ mb/sr was measured for the population of the ${}^{11}\mathrm{Li}$ ground state.

The lifetimes of the first excited $2$${}^{+}$ states in ${}^{62}\mathrm{Fe}$ and ${}^{64}\mathrm{Fe}$ have been measured for the first time using the recoil-distance Doppler shift method after multinucleon transfer reactions in inverse kinematics. A sudden increase of collectivity from ${}^{62}\mathrm{Fe}$ to ${}^{64}\mathrm{Fe}$ is observed. The experimental results are compared with new large-scale shell-model calculations and Hartree-Fock-Bogolyubov–based configuration-mixing calculations using the Gogny D1S interaction. The results give a deeper understanding of the mechanism leading to an onset of collectivity near ${}^{68}\mathrm{Ni}$, which is compared with the situation in the so-called island of inversion around ${}^{32}\mathrm{Mg}$.

The rate of vacuum-changing topological solutions of the gluon field, sphalerons, is estimated to be large at the typical temperatures of heavy-ion collisions, particularly at the Relativistic Heavy Ion Collider. Such windings in the gluon field are expected to produce parity-odd bubbles, which cause separation of positively and negatively charged quarks along the axis of the external magnetic field. This chiral magnetic effect can be mimicked by Chern-Simons modified electromagnetism. Here we present a model of relativistic hydrodynamics including the effects of axial anomalies via the Chern-Simons term.