We describe a new implementation of the quasiparticle random-phase approximation (QRPA) in axially symmetric deformed nuclei with Skyrme and volume-pairing energy-density functionals. After using a variety of tests to demonstrate the accuracy of the code in ${}^{24,26}\mathrm{Mg}$ and ${}^{16}\mathrm{O}$, we report the first fully self-consistent application of the Skyrme QRPA to a heavy deformed nucleus, calculating strength distributions for several $K^{\pi }$ in ${}^{172}\mathrm{Yb}$. We present energy-weighted sums, properties of $\gamma$-vibrational and low-energy $K^{\pi }=0^{+}$ states, and the complete isovector $E1$ strength function. The QRPA calculation reproduces the properties of the low-lying $2^{+}$ states as well or better than it typically does in spherical nuclei.

We combine a recently developed ab initio many-body approach capable of describing simultaneously both bound and scattering states, the ab initio no-core shell model/resonating-group method (NCSM/RGM), with an importance-truncation scheme for the cluster eigenstate basis and demonstrate its applicability to nuclei with mass numbers as high as 17. By using soft similarity renormalization-group-evolved chiral nucleon-nucleon interactions, we first calculate nucleon-${}^4\mathrm{He}$ phase shifts, cross sections, and analyzing powers. Next, we investigate nucleon scattering on ${}^7\mathrm{Li}$, ${}^7\mathrm{Be}$, ${}^{12}\mathrm{C}$, and ${}^{16}\mathrm{O}$ in coupled-channel NCSM/RGM calculations that include low-lying excited states of these nuclei. We check the convergence of phase shifts with the basis size and study $A=8,13$, and 17 bound and unbound states. Our calculations predict low-lying resonances in ${}^8\mathrm{Li}$ and ${}^8\mathrm{B}$ that have not been experimentally clearly identified yet. We are able to reproduce reasonably well the structure of the $A=13$ low-lying states. However, we find that $A=17$ states cannot be described without an improved treatment of ${}^{16}\mathrm{O}$ one-particle-one-hole excitations and $\alpha$ clustering.

The cosmological origins of the two heaviest odd-odd nuclei ${}^{138}\mathrm{La}$ and ${}^{180}\mathrm{Ta}$ are believed to be closely related to the neutrino process. We investigate in detail neutrino-induced reactions on the nuclei. Charged current (CC) reactions ${}^{138}\mathrm{Ba}$(${\nu }_e,e^{-}$)${}^{138}\mathrm{La}$ and ${}^{180}\mathrm{Hf}$(${\nu }_e,e^{-}$)${}^{180}\mathrm{Ta}$ are calculated using the standard quasi-particle random phase approximation (QRPA) with neutron-proton pairing as well as neutron-neutron and proton-proton pairing correlations. For the neutral current (NC) reactions ${}^{139}\mathrm{La}$($\nu ,{\nu }^{\prime }$)${}^{139}\mathrm{La}$${}^{*}$ and ${}^{181}\mathrm{Ta}$($\nu ,{\nu }^{\prime }$)${}^{181}\mathrm{Ta}$${}^{*}$, we generate ground and excited states of the odd-even target nuclei ${}^{139}\mathrm{La}$ and ${}^{181}\mathrm{Ta}$ by operating one quasiparticle to even-even nuclei ${}^{138}\mathrm{Ba}$ and ${}^{180}\mathrm{Hf}$, which are assumed as the BCS ground state. Numerical results for CC reactions are shown to be consistent with recent semiempirical data deduced from the Gamow-Teller strength distributions measured in the (${}^3\mathrm{He}$,$t$) reaction. Results for NC reactions are estimated to be about 4 to 5 times smaller than the results for CC reactions. Finally, cross sections weighted by the incident neutrino flux in the core-collapse supernova are presented for further applications to the network calculations for relevant nuclear abundances.

Di-jet correlations in nucleus-nucleus collisions are studied within the hadron-string-dynamics (HSD) transport approach taking into account the reaction of the medium on the jet energy loss nonperturbatively. A comparison with the STAR and PHENIX data in central $\mathrm{Au}+\mathrm{Au}$ collisions at the Relativistic Heavy Ion Collider energy $\sqrt{s}=200$ GeV is performed differentially (i.e., with respect to correlations in azimuthal angle $\Delta \varphi$ and pseudorapidity $\Delta \eta$). The HSD results do not show enough suppression for the “away-side” jets in accordance with earlier perturbative studies. Furthermore, the “Mach-cone” structure for the angle distribution in the away-side jet as well as “ridge” long-range rapidity correlations in the “near-side” jet—observed by the STAR, PHENIX, and PHOBOS Collaborations—are not seen in the HSD results, thus suggesting a partonic origin.

The critical temperature for $\alpha$-particle condensation in nuclear matter with Fermi surface imbalance between protons and neutrons is determined. The in-medium four-body Schrödinger equation, generalizing the Thouless criterion of the BCS transition, is applied using a Hartree-Fock wave function for the quartet projected onto zero total momentum in matter with different chemical potentials for protons and neutrons.

The spin and configurational structure of excited states of ${}^{127}\mathrm{Cd}$, the two-proton and three-neutron hole neighbor of ${}^{132}\mathrm{Sn}$, has been studied. An isomeric state with a half-life of 17.5(3) $\mu$s was populated in the fragmentation of a ${}^{136}\mathrm{Xe}$ beam on a ${}^9\mathrm{Be}$ target at a beam energy of 750 MeV/u. Time distributions of the delayed $\gamma$ transitions and $\gamma \gamma$ coincidence relations were exploited to construct a decay scheme. The observed yrast (19/2)${}^{+}$ isomer is proposed to have dominant configurations of $\nu (h_{11/2}^{-3})\pi (g_{9/2}^{-1},p_{1/2}^{-1})$, $\nu (h_{11/2}^{-2}{d}_{3/2}^{-1})\pi (g_{9/2}^{-2})$, and $\nu (h_{11/2}^{-2},s_{1/2}^{-1})\pi (g_{9/2}^{-2})$ and to decay by two competing stretched $M2$ and $E3$ transitions. Experimental results are compared with the isotone ${}^{129}\mathrm{Sn}$. The new information provides input for the proton-neutron interaction and the evolution of neutron hole energies in nuclei around the doubly magic ${}^{132}\mathrm{Sn}$ core.

We investigate the roles of deformation on the giant monopole resonance (GMR), particularly the mixing of the giant quadrupole resonance (GQR) and the effects of the neutron excess in the well-deformed nuclei around ${}^{110}\mathrm{Zr}$ and in the drip-line nuclei around ${}^{140}\mathrm{Zr}$ by means of the deformed quasiparticle-random-phase approximation employing the Skyrme and the local-pairing energy-density functionals. It is found that the isoscalar (IS) GMR has a two-peak structure, the lower peak of which is associated with the mixing between the ISGMR and the $K^{\pi }=0^{+}$ component of the ISGQR. The transition strength of the lower peak of the ISGMR grows as the neutron number increases. In the drip-line nuclei, the neutron excitation is dominant over the proton excitation. We find that for an isovector (IV) excitation the GMR has a four-peak structure due to the mixing of the IS and IV modes as well as the mixing of the $K^{\pi }=0^{+}$ component of the IVGQR. In addition to the GMR, we find that the threshold strength is generated by neutrons only.

Squeezed correlations of particle-antiparticle pairs were predicted to exist if the hadron masses were modified in the hot and dense medium formed in high-energy heavy-ion collisions. Although well-established theoretically, they have not yet been observed experimentally. We suggest here a clear method to search for such a signal by analyzing the squeezed correlation functions in terms of measurable quantities. We illustrate this suggestion for simulated $\varphi \varphi$ pairs at the Relativistic Heavy Ion Collider (RHIC) energies.

We construct three new Hartree-Fock-Bogoliubov (HFB) mass models, labeled HFB-19, HFB-20, and HFB-21, with unconventional Skyrme forces containing $t_4$ and $t_5$ terms, i.e., density-dependent generalizations of the usual $t_1$ and $t_2$ terms, respectively. The new forces underlying these models are fitted respectively to three different realistic equations of state of neutron matter for which the density dependence of the symmetry energy ranges from the very soft to the very stiff, reflecting thereby our present lack of complete knowledge of the high-density behavior of nuclear matter. All unphysical instabilities of nuclear matter, including the transition to a polarized state in neutron-star matter, are eliminated with the new forces. At the same time the new models fit essentially all the available mass data with rms deviations of 0.58 MeV and give the same high-quality fits to measured charge radii that we obtained in earlier models with conventional Skyrme forces. Being constrained by neutron matter, these new mass models, which all give similar extrapolations out to the neutron drip line, are highly appropriate for studies of the $r$ process and the outer crust of neutron stars. Moreover, the underlying forces, labeled BSk19, BSk20 and BSk21, respectively, are well adapted to the study of the inner crust and core of neutron stars. The new family of Skyrme forces thus opens the way to a unified description of all regions of neutron stars.

Excited states in the $N=30$ neutron-rich isotope ${}^{49}\mathrm{K}$ have been studied using multinucleon transfer reactions with thin targets and the PRISMA-CLARA spectrometer combined with thick-target $\gamma$-coincidence data from Gammasphere. The $d_{3/2}$ proton-hole state is located 92 keV above the $s_{1/2}$ ground state, and the proton-particle $f_{7/2}$ state is suggested at 2104 keV. Three other levels are established as involving the coupling to $2^{+}$ of two neutrons above the $N=28$ shell. The measured or estimated lifetimes served to reinforce the interpretation of the observed level structure, which is found to be in satisfactory agreement with shell-model calculations.

A formula of $\alpha$-decay energy for superheavy nuclei based on the method of macroscopic model plus shell corrections is proposed. The macroscopic part of this formula is derived from the Bethe-Weizsäcker binding energy formula, and the shell corrections at $N=152$ and $N=162$ are expressed by the Mexican hat wavelet functions. The parameters of this formula are obtained through fitting to 170 $\alpha$-decay energies for nuclei ranging from $Z=90$ to $Z=118$ with $N⩾140$. Numerical results show that 170 existing $\alpha$-decay energies can be reproduced very well; the average and standard deviations between theoretical results and experimental data are 0.177 and 0.226 MeV, respectively. The $\alpha$-decay energies of newly synthesized nuclei ${}^{293,294}117$ and their $\alpha$-decay products are also reproduced very well. In addition, the $\alpha$-decay energies for nuclei with $Z=110$–120 are predicted and compared with the results calculated by the macroscopic-microscopic model. Great differences are found for nuclei with $Z⩾116$ and $N⩾176$ due to the shell effects near the hypothetical doubly magic nucleus ${}^{298}$${114}_{184}$ in the macroscopic-microscopic model. Therefore, by comparing experimental $\alpha$-decay energies measured in the future with the ones predicted by these two methods, one can obtain useful information about the next proton and neutron magic numbers.

The (${}^3\mathrm{He}$,$\hspace{0.5em}d$) single-proton stripping reaction has been performed on targets of ${}^{185,187}\mathrm{Re}$ to investigate the structures of the $4_3^{+}$ states in ${}^{186,188}\mathrm{Os}$. The experiment employed 30 MeV ${}^3\mathrm{He}$ beams, and the reaction products were analyzed with a Q3D spectrograph. Absolute cross sections were determined at nine angles between $5^{°}$ and ${50}^{°}$ for states up to approximately 3 MeV in excitation energy. Large ${\frac{5}{2}}^{+}[402]{}_{\pi }+{\frac{3}{2}}^{+}[402]{}_{\pi }$ two-quasiparticle components are deduced for the $4_3^{+}$ levels of both isotopes. Their magnitudes are in agreement with calculations performed using the quasiparticle phonon model, which predicts a coexistence of a large hexadecapole with a smaller, but sizable, $\gamma$-$\gamma$ component in the $4_3^{+}$.

Photoproduction of ${\pi }^0\eta$ on protons in the energy range from threshold to 1.4 GeV is discussed. The data for representative angular distributions recently obtained at MAMI C are analyzed using an isobar model. The isobars considered are $\Delta (1232)$ and $S_{11}(1535)$ for ${\pi }^{0}p$ and $\eta p$ states, respectively. In accordance with the results of earlier works, the main features of the reaction are explained through the dominance of the $D_{33}$ wave with a relatively small admixture of positive parity resonances. Comparison with recent experimental results for the photon beam asymmetry is carried out.

The $\gamma p\to \eta p$ reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in the energy range from the production threshold of 707 MeV to 1.4 GeV ($1.49⩽W⩽1.87$ GeV). Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz Microtron MAMI-C and momentum analyzed by the Glasgow tagging spectrometer were used for the $\eta$-meson production. Our accumulation of $3.8\times {10}^6$ $\gamma p\to \eta p\to 3{\pi }^{0}p\to 6\gamma p$ events allows a detailed study of the reaction dynamics. The $\gamma p\to \eta p$ differential cross sections were determined for 120 energy bins and the full range of the production angles. Our data show a dip near $W=1680$ MeV in the total cross section caused by a substantial dip in $\eta$ production at forward angles. The data are compared to predictions of previous SAID and MAID partial-wave analyses and to the latest SAID and MAID fits that included our data.

The Zagreb analysis partial-wave $T$ matrices included in the Review of Particle Physics [by the Particle Data Group (PDG)] contain Breit-Wigner parameters only. As the advantages of pole over Breit-Wigner parameters in quantifying scattering matrix resonant states are becoming indisputable, we supplement the original solution with the pole parameters. Because of an already reported numeric error in the $S$${}_{11}$ analytic continuation [Batinić et al., Phys. Rev. C 57, 1004(E) (1997); arXiv:nucl-th/9703023], we declare the old BATINIC 95 solution, presently included by the PDG, invalid. Instead, we offer two new solutions: (A) corrected BATINIC 95 and (B) a new solution with an improved $S$${}_{11}$ $\pi$$N$ elastic input. We endorse solution (B).

Charged particles’ $p_T$ spectra and elliptic flow in $0\%–60\%$ $\mathrm{Au}+\mathrm{Au}$ collisions at the Relativistic Heavy Ion Collider are analyzed in a hydrodynamic model with hot hadronic resonance gas (HRG) in the initial state. Physically conceivable HRG, thermalized in the time scale ${\tau }_i=1\hspace{0.5em}\mathrm{fm}$, at a (central) temperature $T_i=220\hspace{0.5em}\mathrm{MeV}$, with viscosity-to-entropy ratio $\eta /s=0.24$, explains the $p_T$ spectra in all the collision centralities reasonably well. However, centrality dependence of elliptic flow demands continual increase of the viscosity-to-entropy ratio with centrality.

We develop the complex scaling method within the framework of the relativistic mean-field (RMF) model. With the self-consistent nuclear potentials from the RMF model, the complex scaling method is used to study single-particle resonant states in spherical nuclei. As examples, the energies and widths of low-lying neutron resonant states in ${}^{120}\mathrm{Sn}$ are obtained. The results are compared with those from the real stabilization method, the scattering phase-shift method, and the analytic continuation in the coupling constant approach and satisfactory agreements are found.

The scaling properties of elliptic flow of hadrons produced in ultrarelativistic heavy-ion collisions are investigated at low transverse momenta, $p_T\lesssim 2$ GeV. Utilizing empirical parametrizations of a thermalized fireball with collective-flow fields, the resonance recombination model (RRM) is employed to describe hadronization via quark coalescence at the hadronization transition. We reconfirm that RRM converts equilibrium quark distribution functions into equilibrated hadron spectra including the effects of space-momentum correlations on elliptic flow. This provides the basis for a controlled extraction of quark distributions of the bulk matter at hadronization from spectra of multistrange hadrons which are beligeved to decouple close to the critical temperature. The resulting elliptic flow from empirical fits at the BNL Relativistic Heavy Ion Collider exhibits transverse kinetic-energy and valence-quark scaling. Utilizing the well-established concept of sequential freeze-out, the scaling at low momenta extends to bulk hadrons ($\pi$, $K$, $p$) at thermal freeze-out, albeit with different source parameters compared to chemical freeze-out. Elliptic-flow scaling is thus compatible with both equilibrium hydrodynamics and quark recombination.

We study the behavior of hybrid stars by using an extended hadronic and quark SU(3) nonlinear sigma model. The degrees of freedom change naturally, in this model, from hadrons to quarks as the density/temperature increases. At zero temperature, we reproduce massive neutron stars, which contain cores of hybrid matter of 2 km for the nonrotating case and 1.18 and 0.87 km, in the equatorial and polar directions, respectively, for stars that rotate at the Kepler frequency (physical cases lie in between). The cooling of such stars is also analyzed.