The correlation between the pygmy dipole strength and the symmetry energy of nuclear matter is reanalyzed. While previous calculations [A. Klimkiewicz et al., Phys. Rev. C 76, 051603(R) (2007); A. Carbone, G. Colò, A. Bracco, L.-G. Cao, P. F. Bortignon, F. Camera, and O. Wieland, Phys. Rev. C 81, 041301 (2010).] have clearly shown a direct correlation between both quantities, it remains unclear to what extent experimental as well as theoretical uncertainties can allow for an accurate determination of the symmetry energy. For this reason, we have recalculated the low-lying strength distributions of the giant dipole resonances for ${}^{130}$Sn and ${}^{132}$Sn that have been recently measured, taking into account the above uncertainties. The calculations are performed within two microscopic models, namely, the discrete quasiparticle random phase approximation (DRPA) and the quasiparticle continuum RPA, which is an extension of the DRPA that takes the coupling to the single-particle continuum into account in an exact way.

A new dynamical model is developed to describe the whole process of surrogate reactions: Transfer of several nucleons at an initial stage, thermal equilibration of residues leading to washing out of shell effects, and decay of populated compound nuclei are treated in a unified framework. Multidimensional Langevin equations are employed to describe time evolution of collective coordinates with a time-dependent potential energy surface corresponding to different stages of surrogate reactions. The new model is capable of calculating spin distributions of the compound nuclei, one of the most important quantities in the surrogate technique. Furthermore, various observables of surrogate reactions can be calculated, for example, energy and angular distribution of ejectile and mass distributions of fission fragments. These features are important to assess validity of the proposed model itself, to understand mechanisms of the surrogate reactions, and to determine unknown parameters of the model. It is found that spin distributions of compound nuclei produced in ${}^{18}\mathrm{O}+{}^{238}\mathrm{U}\to {}^{16}\mathrm{O}+{}^{240*}\mathrm{U}$ and ${}^{18}\mathrm{O}+{}^{236}\mathrm{U}\to {}^{16}\mathrm{O}+{}^{238*}\mathrm{U}$ reactions are equivalent and much less than 10$\hslash$ and therefore satisfy conditions proposed by Chiba and Iwamoto [Phys. Rev. C 81, 044604 (2010)] if they are used as a pair in the surrogate ratio method.

Explicit relations between the effective-range expansion and the nuclear vertex constant or asymptotic normalization coefficient (ANC) for the virtual decay $B\to A+a$ are derived for an arbitrary orbital momentum together with the corresponding location condition for the ($A+a$) bound-state energy. They are valid both for the charged case and for the neutral case. Combining these relations with the standard effective-range function up to order six makes it possible to reduce to two the number of free effective-range parameters if an ANC value is known from experiment. Values for the scattering length, effective range, and form parameter are determined in this way for the ${}^{16}\mathrm{O}+p$, $\alpha +t$, and $\alpha +{}^3\mathit{He}$ collisions in partial waves where a bound state exists by using available ANCs deduced from experiments. The resulting effective-range expansions for these collisions are valid up to energies larger than 5 MeV.

The vector analyzing power has been measured for the elastic scattering of neutron-rich ${}^6$He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a ${}^6$He nucleus. An optical model analysis revealed that the spin-orbit potential for ${}^6$He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with an $\alpha$+$n$+$n$ cluster folding model suggests that the interaction between a proton and the $\alpha$ core is essentially important in describing the $p$+${}^6$He elastic scattering. The data are also compared with fully microscopic analyses using nonlocal optical potentials based on nucleon-nucleon $g$ matrices.

The near-side ridge structure in the $\Delta \phi$-$\Delta \eta$ correlation observed by the CMS Collaboration for $pp$ collisions at 7 TeV at the Large Hadron Collider can be explained by the momentum kick model in which the ridge particles are medium partons that suffer a collision with the jet and acquire a momentum kick along the jet direction. Similar to the early medium parton momentum distribution obtained in previous analysis for nucleus-nucleus collisions at $\sqrt{s_{{}_{NN}}}=0.2$ TeV, the early medium parton momentum distribution in $pp$ collisions at 7 TeV exhibits a rapidity plateau as arising from particle production in a flux tube.

Here we correct a factor of 2 missed in one of figures and the corresponding sentence in the text. It does not change any conclusions.

Quasielastic excitation functions for the ${}^{16,18}$O $+$ ${}^{60}$Ni systems were measured at energies near and below the Coulomb barrier, at the backward angle θ${}_{\mathrm{LAB}}$ $=$ 161°. The corresponding quasielastic barrier distributions were derived. The data were compared with predictions from coupled channel calculations using a double-folding potential as a bare potential. For the ${}^{16}$O-induced scattering, good agreement was obtained for the barrier distribution by using the projectile default nuclear matter diffuseness obtained from the São Paulo potential systematic, that is, 0.56 fm. However, for the ${}^{18}$O-induced scattering, good agreement was obtained only when the projectile nuclear matter diffuseness was changed to 0.62 fm. Therefore, in this paper we show how near-barrier quasielastic scattering can be used as a sensitive tool to derive nuclear matter diffuseness.

Although nuclear energy-density functionals are determined primarily by fitting to ground-state properties, they are often applied in nuclear astrophysics to excited states, usually through the quasiparticle random-phase approximation (QRPA). Here we test the Skyrme functionals SkM${}^{*}$ and SLy4 along with the self-consistent QRPA by calculating properties of low-lying vibrational states in a large number of well-deformed even-even rare-earth nuclei. We reproduce trends in energies and transition probabilities associated with $\gamma$-vibrational states, but our results are not perfect and indicate the presence of multiparticle-hole correlations that are not included in the QRPA. The Skyrme functional SkM${}^{*}$ performs noticeably better than SLy4. In a few nuclei, changes in the treatment of the pairing energy functional have a significant effect. The QRPA is less successful with “$\beta$-vibrational” states than with the $\gamma$-vibrational states.

The semi-empirical macroscopic-microscopic mass formula is further improved by considering some residual corrections. The rms deviation from 2149 known nuclear masses is significantly reduced to 336 keV, even lower than that achieved with the best of the Duflo-Zuker models. The $\alpha$-decay energies of super-heavy nuclei, the Garvey-Kelson relations, and the isobaric multiplet mass equation (IMME) can be reproduced remarkably well with the model, and the predictive power of the mass model is good. With a systematic study of 17 global nuclear mass models, we find that the quadratic form of the IMME is closely related to the accuracy of nuclear mass calculations when the Garvey-Kelson relations are reproduced reasonably well. Fulfilling both the IMME and the Garvey-Kelson relations seem to be two necessary conditions for improving the quality of the model prediction. Furthermore, the $\alpha$-decay energies of super-heavy nuclei should be used as an additional constraint on global nuclear mass models.

The reaction ${}^{234}$U($\vec{\mathrm{d}},t$)${}^{233}$U was measured at the Munich Q3D magnetic spectrometer with a polarized deuteron beam. The beam energy was 22 MeV, and a vector polarization of the deuterons of 80% was achieved. Angular distributions of the reaction cross section and analyzing power at seven angles between 5${}^{\circ }$ and 35${}^{\circ }$ were analyzed. Spin and parity assignments for 33 states were determined by comparison with results from distorted wave Born approximation (DWBA) calculations. Based on these assignments and energy systematics, the observed states were sorted into rotational bands. The Nilsson configurations of the bands are identified by examining the population strengths within each band. Two rotational bands with Nilsson configurations 1/2[501] and 3/2[501] could be identified for the first time.

We have derived approximate analytical formulas describing the quasistationary fission rate of excited nuclei (the Kramers rates). These rates are compared with those resulting from dynamical modeling using the Smoluchowski equation (the dynamical rates). Contrary to the original Kramers approach, we have accounted for the microcanonical nature of the fission process. The influence of the potential at the scission point on the fission rates is also studied. Comparison with the dynamical rates enables us to define the accuracy of the Kramers rates in the wide range of the ratio of the fission barrier height $B_f$ to the temperature at the quasistationary state $T_c$ up to 16. These high values are not reachable within the traditional Langevin approach.

We use (3 $+$ 1) dimensional ideal hydrodynamics to describe the space-time evolution of strongly interacting matter created in Au $+$ Au and Pb $+$ Pb collisions. The model is applied for the domain of bombarding energies 1–160 GeV/nucleon which includes future NICA (Dubna) and FAIR (Darmstadt) experiments. Two equations of state are used, the first one corresponding to resonance hadron gas and the second one including the deconfinement phase transition. The initial state is represented by two Lorentz-boosted nuclei. Dynamic trajectories of matter in the central box of the system are analyzed. They can be well represented by a fast shock-wave compression followed by a relatively slow isentropic expansion. The parameters of collective flows and hadronic spectra are calculated under assumption of the isochronous freeze-out. It is shown that the deconfinement phase transition leads to broadening of proton rapidity distributions, increase of elliptic flows, and formation of the directed antiflow in the central rapidity region. These effects are most pronounced at bombarding energies around 10 GeV/nucleon, when the system spends the longest time in the mixed phase. From the comparison with three-fluid calculations we conclude that the transparency effects are not so important in central collisions at NICA–FAIR energies (below 30 GeV/nucleon).

In noncentral collisions between ultrarelativistic heavy ions, the freeze-out distribution is anisotropic, and its major longitudinal axis may be tilted away from the beam direction. The shape and orientation of this distribution are particularly interesting, as they provide a snapshot of the evolving source and reflect the space-time aspect of anisotropic flow. Experimentally, this information is extracted by measuring pion Hanbury-Brown–Twiss (HBT) radii as a function of angle with respect to the reaction plane. The connection between measured radius oscillations and the underlying geometry is necessarily model-dependent; many existing formulas are strictly valid only for Gaussian sources with no collective flow. With a realistic transport model of the collision, which generates flow and non-Gaussian sources, we find that these formulas approximately reflect the anisotropy of the freeze-out distribution.

We analyze the dispersion correction to elastic parity violating electron-proton scattering due to $\gamma Z$ exchange. In particular, we explore the theoretical uncertainties associated with modeling contributions of hadronic intermediate states. Taking into account constraints from low- and high-energy, parity-conserving electroproduction measurements, choosing different models for contributions from the nonresonant processes, and performing the corresponding flavor rotations to obtain the electroweak amplitude, we arrive at an estimate of the uncertainty in the total contribution to the parity-violating asymmetry. At the kinematics of the Q-Weak experiment, we obtain a correction to the asymmetry equivalent to a shift in the proton weak charge of $(0.0054\pm 0.0020)$. This should be compared to the value of the proton’s weak charge of $Q_W^p=0.0713\pm 0.0008$ that includes Standard Model contributions at tree level and one-loop radiative corrections. Therefore, we obtain a new Standard Model prediction for the parity-violating asymmetry in the kinematics of the Q-Weak experiment of $(0.0767\pm 0.0008\pm {0.0020}_{\gamma Z})$. The latter error leads to a relative uncertainty of 2.8% in the determination of the proton’s weak charge and is dominated by the uncertainty in the isospin structure of the inclusive cross section. We argue that future parity-violating inelastic $ep$ asymmetry measurements at low to moderate $Q^2$ and $W^2$ could be exploited to reduce the uncertainty associated with the dispersion correction. Because the corresponding shift and error bar decrease monotonically with decreasing beam energy, a determination of the proton’s weak charge with a lower-energy experiment or measurements of “isotope ratios” in atomic parity violation could provide a useful cross-check on any implications for physics beyond the Standard Model derived from the Q-Weak measurement.

The tensor and spin-orbit forces contribute essentially to the formation of the spin mean field, and give rise to the same dynamical effect, namely spin polarization. In this paper, based on time-dependent density functional calculations, we show that the tensor force, which usually acts like a small correction to the spin-orbit force, becomes more important in heavy-ion reactions and the effect increases with the mass of the system.

The experimental observables for the elastic reaction induced by protons scattering from electrons are calculated in the Born approximation. The differential cross section and polarization observables have been derived assuming one-photon exchange. Numerical estimates are given for spin correlation coefficients, polarization transfer coefficients, and depolarization coefficients in a wide kinematical range. Specific attention is given to the kinematical conditions; that is, to the specific range of incident energy and transferred momentum.

We report measurements of the cross section and a complete set of polarization transfer observables for the ${}^{16}\mathrm{O}(\vec{p},\vec{n}){}^{16}\mathrm{F}$ reaction at a bombarding energy of $T_p$ $=$ 296 MeV and a reaction angle of ${\theta }_{\mathit{lab}}$ $=$ $0^{\circ }$. The data are compared with distorted-wave impulse approximation calculations employing the large configuration-space shell-model (SM) wave functions. The well-known Gamow-Teller and spin-dipole (SD) states at excitation energies of $E_x$ $\lesssim$ 8 MeV have been reasonably reproduced by the calculations except for the spin-parity $J^{\pi }$ $=$ $2^{-}$ state at $E_x$ $=$ 5.86 MeV. The SD resonance at $E_x$ $\simeq$ 9.5 MeV appears to have more $J^{\pi }$ $=$ $2^{-}$ strength than $J^{\pi }$ $=$ $1^{-}$ strength, consistent with the calculations. The data show significant strength in the spin-longitudinal polarized cross section $I{D}_L\left(0^{\circ }\right)$ at $E_x$ $\simeq$ 15 MeV, which indicates the existence of the $J^{\pi }$ $=$ $0^{-}$ SD resonance as predicted in the SM calculations.

We present a trial to obtain a systematic behavior of the results available in the literature on the complete and incomplete fusion induced by the weakly bound projectile ${}^9$Be on targets with different masses and/or charges. We stress that although the incomplete-fusion probability and the complete-fusion suppression are very closely related quantities, the first is an experimental value whereas the later is model dependent. A trend of systematic behavior for the incomplete-fusion probability as a function of the target charge is achieved, but not for the complete-fusion suppression.

The ground state of the proton-rich nucleus ${}^{23}$Al has been studied by one-proton removal on a carbon target at about 50 MeV/nucleon using the EXOGAM $+$ SPEG experimental setup at GANIL. Longitudinal momentum distributions of the ${}^{22}$Mg breakup fragments, inclusive and in coincidence with $\gamma$ rays de-exciting the residues, were measured. The ground-state structure of ${}^{23}$Al is found to be a configuration mixing of a $d$-orbital valence proton coupled to four core states—0${}_{\text{gs}}^{+}$, 2${}_1^{+}$, 4${}_1^{+}$, 4${}_2^{+}$. We confirm the ground state spin and parity of ${}^{23}$Al as $J^{\pi }=5/2^{+}$. The measured exclusive momentum distributions are compared with extended Glauber model calculations to extract spectroscopic factors and asymptotic normalization coefficients (ANCs). The spectroscopic factors are presented in comparison with those obtained from large-scale shell model calculations. We determined the asymptotic normalization coefficient of the nuclear system ${}^{23}$Al${}_{\text{gs}}$ $\to$ ${}^{22}$Mg(0${}^{+}$) $+$ $p$ to be $C_{d_{5/2}}^2{(}^{23}{\text{Al}}_{\text{gs}})=(3.90\pm 0.44)\times {10}^3{\text{fm}}^{-1}$, and used it to infer the stellar reaction rate of the direct radiative proton capture ${}^{22}$Mg($p$,$\gamma$)${}^{23}$Al. Astrophysical implications related to ${}^{22}$Na nucleosynthesis in ONe novae and the use of one-nucleon breakup at intermediate energies as an indirect method in nuclear astrophysics are discussed.