A set of new theoretical measures for the optimal determination of collision amplitudes is formulated in two parts: (i) the localized virial conditions, which optimize the scattering solutions, and (ii) the temperate function criteria, which identify and discard spurious solutions. Thus, for the first time the quality of approximations introduced on the scattering function can be systematically improved, and the collision amplitudes are then evaluated with the improved wave functions. The measures proposed are not an extremum principle, so that the improvement of the amplitude is not monotonic. But, in its various forms, the theory should be applicable generally to most collision systems, at all scattering energies and even above the breakup threshold.

The complete fusion of ${}^9\mathrm{Be}$ with ${}^{144}\mathrm{Sm}$ and ${}^{208}\mathrm{Pb}$ targets is calculated in the coupled-channels approach. The calculations include couplings among the 3/$2^{-}$, 5/$2^{-}$, and 7/$2^{-}$ states in the $K=3/2$ ground-state rotational band of ${}^9\mathrm{Be}$. It is shown that the $B(E2)$ values for the excitation of these states are accurately described in the rotor model. The interaction of the strongly deformed ${}^9\mathrm{Be}$ nucleus with a spherical target is calculated using the double-folding technique and the effective M3Y interaction, which is supplemented with a repulsive term that is adjusted to optimize the fit to the data for the ${}^{144}\mathrm{Sm}$ target. The complete fusion is described by ingoing-wave boundary conditions. The decay of the unbound excited states in ${}^9\mathrm{Be}$ is considered explicitly in the calculations by using complex excitation energies. The model gives an excellent account of the complete fusion (CF) data for ${}^9\mathrm{Be}+{}^{144}\mathrm{Sm}$, and the cross sections for the decay of the excited states are in surprisingly good agreement with the incomplete fusion (ICF) data. Similar calculations for ${}^9\mathrm{Be}+{}^{208}\mathrm{Pb}$ explain the total fusion data at high energies but fail to explain the CF data, which are suppressed by 20%, and the calculated cross section for the decay of excited states is a factor of 3 smaller than the ICF data at high energies. Possible reasons for these discrepancies are discussed.

The azimuthal angular dependence of the nuclear modification factor $R_{\mathit{AA}}(p_T,\varphi ,N_{\mathrm{part}})$ recently obtained by PHENIX is related at low $p_T$ to the trigger $\varphi$ dependence of the ridge yield as measured by STAR in a framework in which the azimuthal anisotropy is driven by semihard scattering near the surface. Careful consideration of the initial geometry leads to the determination of a surface segment in which the production of semihard partons are responsible for the $\varphi$ dependence of the inclusive distribution on the one hand and for the angular correlation in ridge phenomenology on the other. With $v_2$ also being well reproduced along with $R_{\mathit{AA}}$ and ridge yield, all relevant $\varphi$ dependencies in heavy-ion collisions can now be understood in a unified description that emphasizes the ridge production whether or not a trigger is used.

Near- and sub-barrier fusion cross sections have been measured for the system ${}^{58}\mathrm{Ni}+{}^{54}\mathrm{Fe}$, and the fusion barrier distribution has been extracted. The measured cross sections cover the range from $\simeq$1 $\mu$b up to around 500 mb. Close analogies are found between the extracted barrier distribution and the available data on ${}^{58}\mathrm{Ni}+{}^{60}\mathrm{Ni}$, indicating the dominating influence of complex surface vibrations on the fusion of ${}^{58}\mathrm{Ni}+{}^{54}\mathrm{Fe}$. The present data on ${}^{58}\mathrm{Ni}+{}^{54}\mathrm{Fe}$ are well reproduced by standard coupled-channels calculations in the measured energy range, including quadrupole and octupole phonons in both colliding nuclei.

A closed expression is obtained for the cross-section for Coulomb excitation of levels of the giant dipole resonance of given angular momentum and phonon number. Applications are made to the Goldhaber-Teller and Steinwedel-Jensen descriptions of the resonance at relativistic bombarding energies.

We construct nonrelativistic versions of relativistic nonlinear hadronic point-coupling models, based on new normalized spinor wave functions after small component reduction. These expansions give us energy density functionals that can be compared to their relativistic counterparts. We show that the agreement between the nonrelativistic limit approach and the Skyrme parametrizations becomes strongly dependent on the incompressibility of each model. We also show that the particular case $A=B=0$ (Walecka model) leads to the same energy density functional of the Skyrme parametrizations SV and ZR2, while the truncation scheme, up to order ${\rho }^3$, leads to parametrizations for which $\sigma =1$.

Recent investigations show that the second-order perturbation calculations of electric dipole moments (EDM) from the finite nuclear size as well as the relativistic effects are all canceled out by the third-order perturbation effects and that this is due to electron screening. To derive the nucleon EDM from the nucleus, we propose to measure the EDM of an ionic system. In this case, it is shown that the nucleon EDM can survive by the reduction factor of 1/$Z$ for the ionic system with one electron stripped off.

A recent discussion of the ${}^{18}\mathrm{F}$($p$,$\alpha$) reaction [N. de Séréville et al., Phys. Rev. C 79, 015801 (2009)] questions our previous analysis of interference effects in this reaction. We address these questions and demonstrate that our previous analysis is indeed appropriate.

New results of $(\alpha ,\gamma )$ and $(\alpha ,n)$ reaction cross section measurements close to the reaction thresholds support the setting up of recent parameters of the $\alpha$-particle optical model potential (OMP) below the Coulomb barrier. Particular features of the $\alpha$-particle optical potential at energies below the Coulomb barrier explain the failure of using the OMP parameters obtained by analysis of only $\alpha$-particle elastic scattering at higher energies.

We study the equation of state of neutron matter using a family of unitarity potentials, all of which are constructed to have infinite ${}^1{S}_0$ scattering lengths $a_s$. For such a system, a quantity of much interest is the ratio $\xi =E_0/E_0^{\mathrm{free}}$, where $E_0$ is the true ground-state energy of the system and $E_0^{\mathrm{free}}$ is that for the noninteracting system. In the limit of $a_s\to \pm \infty$, often referred to as the unitary limit, this ratio is expected to approach a universal constant, namely $\xi ~0.44(1)$. In the present work we calculate this ratio $\xi$ using a family of hard-core square-well potentials whose $a_s$ can be exactly obtained, thus enabling us to have many potentials of different ranges and strengths, all with infinite $a_s$. We have also calculated $\xi$ using a unitarity CDBonn potential obtained by slightly scaling its meson parameters. The ratios $\xi$ given by these different unitarity potentials are all close to each other and also remarkably close to 0.44, suggesting that the above ratio $\xi$ is indifferent to the details of the underlying interactions as long as they have infinite scattering length. A sum-rule and scaling constraint for the renormalized low-momentum interaction in neutron matter at the unitary limit is studied. The importance of pairing in our all-order ring diagram and model-space HF calculations of neutron matter is discussed.

A field-theoretic parametrization is proposed for nucleon electromagnetic form factors at momentum transfer less than 600 MeV. The parametrization is part of a larger effective field theory Lagrangian that is Lorentz covariant and chirally symmetric and that has been used to successfully describe bulk and single-particle properties of medium- to heavy-mass nuclei. The parametrization is based on vector meson dominance and a derivative expansion of nucleon couplings to the electromagnetic fields. At lowest order in the expansion, it is possible to fit all four parameters to modern data on the rms radii of the nucleon form factors. At next-to-leading order it is possible to fit the form factors to within a few percent up to momentum transfers of 600 MeV. The vector meson dominance contributions are crucial in this fit, because a simple expansion in powers of momentum transfer would require many terms to achieve comparable accuracy. The ability to fit single-nucleon form factors up to 600 MeV momentum transfer makes possible the study of two-body electromagnetic exchange currents within this effective field theory framework.

The production of strange mesons in collisions of $\mathrm{Ar}+\mathrm{KCl}$ at a kinetic beam energy of 1.756$A$ GeV is studied within a transport model of Boltzmann-Ühling-Uhlenbeck type. In particular, $\varphi ,K^{+}$, and $K^{-}$ yields and spectra are compared to the data measured recently by the HADES Collaboration and the $\varphi$ yield measured previously by the FOPI Collaboration. Our results are in agreement with these data, thus presenting an interpretation of the subleading role of $\varphi$ decays into $K^{-}$’s and confirming the importance of the strangeness-exchange channels for $K^{-}$ production.

Recently we have shown that there are crucial similarities in the physics of cosmic microwave background radiation (CMBR) anisotropies and the flow anisotropies in relativistic heavy-ion collision experiments (RHICE). We also argued that, following CMBR anisotropy analysis, a plot of root-mean-square values of the flow coefficients, calculated in a laboratory-fixed frame for RHICE, can yield important information about the nature of initial state anisotropies and their evolution. Here we demonstrate the strength of this technique by showing that elliptic flow for noncentral collisions can be directly determined from such a plot without any need for the determination of the event plane.

Photoneutron cross sections were measured for ${}^{96}\mathrm{Zr}$ near neutron threshold with quasimonochromatic laser-Compton-scattering $\gamma$-ray beams. A systematic analysis of photoneutron and radiative neutron capture data for zirconium isotopes within the statistical model calculation leads to a unified picture of low-energy $\gamma$-ray strengths for zirconium isotopes that is described by the HFB $+$ QRPA model of $E1$ strength supplemented with an extra $\gamma$ strength attributed to a giant $M1$ resonance. Results of the systematic analysis including radiative neutron capture cross sections for radioactive ${}^{95}\mathrm{Zr}$ and ${}^{93}\mathrm{Zr}$ nuclei are presented.

We calculate the ${}^3\mathrm{He}+\mathit{p}$ scattering phase shifts for the $S$ and $P$ waves in a microscopic cluster model, in which the description of the ${}^3\mathrm{He}$ wave function is extended from a simple $(0s){}^3$ model to a three-body model. We employ two different nucleon-nucleon interactions, the Minnesota (MN) and AV$8^{\text{'}}$ potentials, to investigate the role of the $d+2\mathit{p}$ channel in the low-energy phase shifts. The role of the $d+2\mathit{p}$ channel in the $P$-wave phase shifts is very sensitive to the choice of the potential. The $d+2\mathit{p}$ channel is indispensable in reproducing the resonant phase shifts in the AV$8^{\text{'}}$ potential while it plays a minor role in the MN potential. On the contrary, the role of this channel in the $S$-wave nonresonant phase shifts is negligible in both potentials.

High-spin excited states in the neutron-rich nucleus ${}^{140}\mathrm{Cs}$ were re-investigated from the spontaneous fission of ${}^{252}\mathrm{Cf}$ with the Gammasphere detector array. Seven new transitions at low and moderate spin and 13 at high spin were observed in ${}^{140}\mathrm{Cs}$ and the level scheme of ${}^{140}\mathrm{Cs}$ was extended to 3794 keV with a new sideband. Spins and parities were assigned to levels based on angular correlation measurements and the systematics in the $N=85$ isotones.

Two integral relations derived from the Kohn variational principle (KVP) are used for describing scattering states. In usual applications the KVP requires the explicit form of the asymptotic behavior of the scattering wave function. This is not the case when the integral relations are applied since, due to their short-range nature, the only condition for the scattering wave function $\Psi$ is that it be the solution of $(H-E)\Psi =0$ in the internal region. Several examples are analyzed for the computation of phase shifts from bound-state-type wave functions or, in the case of the scattering of charged particles, it is possible to obtain phase shifts using free asymptotic conditions. As a final example we discuss the use of the integral relations in the case of the hyperspherical adiabatic method.

We propose a general approach to characterise fluctuations of measured cross sections of nuclear giant resonances. Simulated cross sections are obtained from a particular, yet representative, self-energy that contains all information about fragmentations. Using a wavelet analysis, we demonstrate the extraction of time scales of cascading decays into configurations of different complexity of the resonance. We argue that the spreading widths of collective excitations in nuclei are determined by the number of fragmentations as seen in the power spectrum. An analytic treatment of the wavelet analysis using a Fourier expansion of the cross section confirms this principle. A simple rule for the relative lifetimes of states associated with hierarchies of different complexity is given.

Fusion reactions of heavy ions are investigated by employing a simple stochastic semi-classical model, which includes coupling between the relative motion and low frequency collective surface modes of colliding ions similarly to the quantal coupled-channels description. The quantal effect enters into the calculation through the initial zero-point fluctuations of the surface vibrations. A good agreement with results of coupled-channels calculations as well as experimental data is obtained for fusion cross sections of Ni isotopes. The internal excitations in nonfusing events as well as the fusion time are investigated.