We apply the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) model to questions relevant to current and future long-baseline neutrino experiments, and we address in particular the relevance of charged-current reactions for neutrino-disappearance experiments. A correct identification of charged-current quasielastic (CCQE) events—which is the signal channel in oscillation experiments—is relevant for neutrino energy reconstruction and thus for the oscillation result. We show that about $20\%$ of the quasielastic cross section is misidentified in present-day experiments and has to be corrected for by means of event generators. Furthermore, we show that a significant part of $1{\pi }^{+}$ ($>$ $40\%$) events is misidentified as CCQE events, mainly caused by pion absorption in the nucleus. We also discuss the dependence of both of these numbers on experimental detection thresholds. We further investigate the influence of final-state interactions on the neutrino energy reconstruction.

We have carried out a wide study of cold nuclear matter (CNM) effects on $J/\psi$ production in $d$Au, CuCu and AuAu collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV. We have studied the effects of three different gluon-shadowing parametrizations, using the usual simplified kinematics for which the momentum of the gluon recoiling against the $J/\psi$ is neglected as well as an exact kinematics for a $2\to 2$ process; namely $g+g\to J/\psi +g$ as expected from LO pQCD. We have shown that the rapidity distribution of the nuclear modification factor $R_{d\mathrm{Au}}$, and particularly its antishadowing peak, is systematically shifted toward larger rapidities in the $2\to 2$ kinematics, irrespective of which shadowing parametrization is used. In turn, we have noted differences in the effective final-state nuclear absorption needed to fit the PHENIX $d$Au data. Taking advantage of our implementation of $2\to 2$ kinematics, we have also computed the transverse momentum dependence of the nuclear modification factor, which cannot be predicted with the usual simplified kinematics. All the corresponding observables have been computed for CuCu and AuAu collisions and compared to the PHENIX and STAR data. Finally, we have extracted the effective nuclear absorption from the recent measurements of $R_{\mathrm{CP}}$ in $d$Au collisions by the PHENIX collaboration.

We discuss various mechanisms for the creation of an asymmetric charge fluctuation with respect to the reaction plane among hadrons emitted in relativistic heavy-ion collisions. We show that such mechanisms exist in both the hadronic gas and the partonic phases of quantum chromodynamics. The mechanisms considered here all require the presence of a strong magnetic field (the “chiral magnetic effect”), but they do not involve parity or charge-parity violations. We analyze how a transient local electric current fluctuation generated by the chiral magnetic effect can dynamically evolve into an asymmetric charge distribution among final-state hadrons in momentum space. We estimate the magnitude of the event-by-event fluctuations of the final-state charge asymmetry owing to partonic and hadronic mechanisms.

An isomeric one-quasineutron state, likely based on the $[725]11/2^{-}$ Nilsson level, was identified in ${}^{261}\mathrm{Sg}$ by its decay via internal conversion electrons. The state has an excitation energy of $\approx 200$ keV and a half-life of $9.0_{-1.5}^{+2.0}$ $\mu$s. ${}^{261}\mathrm{Sg}$ has the highest $Z$ and $A$ of any nucleus in which the electromagnetic decay of an isomeric state was observed to date. A separate experiment was performed on the $\alpha$ daughter nucleus of ${}^{261}\mathrm{Sg}$, namely ${}^{257}\mathrm{Rf}$. Spectroscopy of delayed $\gamma$ rays and converted electrons from ${}^{257}\mathrm{Rf}$ resulted in the identification of a $K$ isomer at an excitation energy of $\approx 1125$ keV with a half-life of 134.9 $\pm$ 7.7 $\mu$s. The spin of the isomeric state is tentatively assigned $I=21/2,23/2$ and the state likely decays to a rotational band built on the $[725]11/2^{-}$ Nilsson level via a $\Delta K=5$ or 6 transition. The present results provide new information on excited states in the transactinide region, which is important for testing models of the heaviest elements.

The neutron-rich $N=50$ isotones ${}^{82}\mathrm{Ge}$ and ${}^{84}\mathrm{Se}$ were investigated using intermediate-energy Coulomb excitation on a ${}^{197}\mathrm{Au}$ target and inelastic scattering on ${}^9\mathrm{Be}$. As typical for intermediate-energy Coulomb excitation with projectile energies exceeding 70 MeV/nucleon, only the first $2^{+}$ states were excited in ${}^{82}\mathrm{Ge}$ and ${}^{84}\mathrm{Se}$. However, in the inelastic scattering on a ${}^9\mathrm{Be}$ target, a strong population of the first $4^{+}$ state was observed for ${}^{84}\mathrm{Se}$, while there is no indication of a similarly strong excitation of the corresponding state in the neighboring even-even isotone ${}^{82}\mathrm{Ge}$. The results are discussed in the framework of systematics and shell-model calculations using three different effective interactions.

Tensor effects in shell evolution are studied within the mean-field approach. Particular attention is paid to the analysis of the magic gaps in different regions of the nuclear chart, namely, $Z,N=8$, 20, and 28. Hartree-Fock calculations with Skyrme and Gogny interactions are performed where the tensor term has a zero and finite range, respectively. Results obtained with and without the tensor component are compared between them and with the experimental data, when available. To complete this analysis, the tensor effect is also investigated within the relativistic Hartree-Fock model, where the exchange of $\rho$ mesons and pions is taken into account. It turns out that the tensor effect in the evolution of the magic gaps can be more easily identified in the cases $Z,N=8$ and 20, whereas the interpretation of the effect is more complicated for $Z$ or $N=$ 28. Consequently, we indicate the regions defined by the magic numbers 8 and 20 as suitable for fitting the tensor parameters in a mean-field approach: We suggest to include explicitly the data associated to these gap evolutions in the fitting procedures. In general, with the parametrizations used in this work (which have not been fitted on these data), the mean-field results obtained with the tensor contribution do not reproduce the experimental trend, that is, the reduction of the gaps at 8 and 20 that is observed when going toward the drip lines. Since some of the considered nuclei have $N=Z$, a discussion will be devoted to the interpretation of the experimental data concerning these nuclei and to the Wigner-energy correction.

The variation of $E(2_1^{+})$ of ${}^{134–140}\mathrm{Sn}$ calculated with empirical SMPN interaction has striking similarity with that of experimental $E(2_1^{+})$ of even-even ${}^{18–22}\mathrm{O}$ and ${}^{42–48}\mathrm{Ca}$, showing clearly that $N=84$–88 spectra exhibit the effect of gradually filling up the $\nu (2f_{7/2})$ orbital, which finally culminates in a new shell closure at $N=90$. Realistic two-body interaction CWG does not show this feature. Spin-tensor decomposition of SMPN and CWG interactions and variations of their components with valence neutron number reveals that the origin of the shell closure at ${}^{140}\mathrm{Sn}$ lies in the three-body effects. Calculations with CWG3M, which is obtained by including a simple three-body monopole term in the CWG interaction, predict decreasing $E(2_1^{+})$ for ${}^{136,138}\mathrm{Sn}$ and a shell closure at ${}^{140}\mathrm{Sn}$.

Within the framework of a generalized factorization, semi-inclusive deeply inelastic scattering (SIDIS) cross sections can be expressed as a series of products of collinear hard parts and transverse-momentum-dependent (TMD) parton distributions and correlations. The azimuthal asymmetry $\langle \cos \varphi \rangle$ of unpolarized SIDIS in the small transverse-momentum region will depend on both twist-2 and -3 TMD quark distributions in target nucleons or nuclei. Nuclear broadening of these twist-2 and -3 quark distributions due to final-state multiple scattering in nuclei is investigated and the nuclear dependence of the azimuthal asymmetry $\langle \cos \varphi \rangle$ is studied. It is shown that the azimuthal asymmetry is suppressed by multiple parton scattering and the transverse-momentum dependence of the suppression depends on the relative shape of the twist-2 and -3 quark distributions in the nucleon. A Gaussian ansatz for TMD twist-2 and -3 quark distributions in nucleon is used to demonstrate the nuclear dependence of the azimuthal asymmetry and to estimate the smearing effect due to fragmentation.

The effective interaction hyperspherical-harmonics method, formulated for local forces, is generalized to accommodate nonlocal interactions. As for local potentials this formulation retains the separation of the hyper-radial part leading solely to a hyperspherical effective interaction. By applying the method to study ground-state properties of ${}^4\mathrm{He}$ with a modern effective-field-theory nucleon-nucleon potential model (Idaho-N3LO), one finds a substantial acceleration in the convergence rate of the hyperspherical-harmonics series. Also studied are the binding energies of the six-body nuclei ${}^6\mathrm{He}$ and ${}^6\mathrm{Li}$ with the JISP16 nuclear force. Again an excellent convergence is observed.

We construct density-dependent class III charge symmetry violating (CSV) potential caused by the mixing of $\pi$-$\eta$ mesons with off-shell corrections. The density dependence enters through the nonvanishing $\pi$-$\eta$ mixing driven by both the neutron-proton mass difference and their asymmetric density distribution. The contribution of density-dependent mixing to the CSV potential is found to be appreciably larger than that of the vacuum part.

Spin and pseudospin symmetries in the spectra of nucleons and antinucleons are studied in a relativistic mean-field theory with scalar and vector Woods-Saxon potentials, in which the strength of the latter is allowed to change. We observe that, for nucleons and antinucleons, the spin symmetry is of perturbative nature and it is almost an exact symmetry in the physical region for antinucleons. The opposite situation is found in the pseudospin symmetry case, which is better realized for nucleons than for antinucleons, but is of dynamical nature and cannot be viewed in a perturbative way for either nucleons or antinucleons. This is shown by computation of the spin-orbit and pseudospin-orbit couplings for selected spin and pseudospin partners in both spectra.

Within the interacting Fermi gas model for isospin asymmetric nuclear matter, effects of the in-medium three-body interaction and the two-body short-range tensor force owing to the $\rho$ meson exchange, as well as the short-range nucleon correlation on the high-density behavior of the nuclear symmetry energy, are demonstrated respectively in a transparent way. Possible physics origins of the extremely uncertain nuclear symmetry energy at suprasaturation densities are discussed.

The ratio of the symmetry energy coefficient to temperature, $a_{\mathrm{sym}}/T$, in Fermi energy heavy-ion collisions, was experimentally extracted as a function of the fragment atomic number using isoscaling parameters and the variance of the isotope distributions. The extracted values were compared to the results of calculations made with an antisymmetrized molecular dynamics (AMD) model employing a statistical decay code to account for deexcitation of excited primary fragments. The experimental values are in good agreement with the values calculated from the final ground-state products but are significantly different from those characterizing the yields of the primary AMD fragments.

We investigate the influence of the central two-body nucleon-nucleon correlations on several quantities observed in relativistic heavy-ion collisions. It is demonstrated with explicit Monte Carlo simulations that the basic correlation measures observed in relativistic heavy-ion collisions, such as the fluctuations of participant eccentricity, initial size fluctuations, or the fluctuations of the number of sources producing particles, are all sensitive to the inclusion of the two-body correlations. The effect is at the level of about 10–20%. Moreover, the realistic (Gaussian) correlation function gives indistinguishable results from the hard-core repulsion, with the expulsion distance set to 0.9 fm. Thus, we verify that for investigations of the considered correlation measures, it is sufficient to use the Monte Carlo generators accounting for the hard-core repulsion.

Heavy-ion reactions and other collective dynamical processes are frequently described by different theoretical approaches for the different stages of the process, like initial equilibration stage, intermediate locally equilibrated fluid dynamical stage, and final freeze-out stage. For the last stage, the best known is the Cooper-Frye description used to generate the phase space distribution of emitted, noninteracting particles from a fluid dynamical expansion or explosion, assuming a final ideal gas distribution, or (less frequently) an out-of-equilibrium distribution. In this work we do not want to replace the Cooper-Frye description, but rather clarify the ways of using it and how to choose the parameters of the distribution and, eventually, how to choose the form of the phase space distribution used in the Cooper-Frye formula. Moreover, the Cooper-Frye formula is used in connection with the freeze-out problem, while the discussion of transition between different stages of the collision is applicable to other transitions also. More recently, hadronization and molecular dynamics models have been matched to the end of a fluid dynamical stage to describe hadronization and freeze-out. The stages of the model description can be matched to each other on space-time hypersurfaces (just like through the frequently used freeze-out hypersurface). This work presents a generalized description of how to match the stages of the description of a reaction to each other, extending the methodology used at freeze-out, in simple covariant form which is easily applicable in its simplest version for most applications.

Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector for photon energies between 0.92 and 1.68 GeV at the electron stretcher accelerator ELSA. The beam asymmetry $\Sigma$ has been extracted for ${115}^{°}<{\theta }_{\mathrm{c}.\mathrm{m}.}<{155}^{°}$ of the ${\pi }^0$ meson and for ${\theta }_{\mathrm{c}.\mathrm{m}.}<{60}^{°}$. The new beam-asymmetry data cover the very forward region, which extend previously published data for the same reaction by our collaboration and improve the world database for photon energies above 1.5 GeV. The angular dependence of $\Sigma$ shows overall good agreement with the SAID parametrization.

The ${}^{14}\mathrm{O}(\alpha ,p){}^{17}\mathrm{F}$ reaction is an important trigger reaction leading to the $\alpha p$ process in x-ray bursts. The inclusion of reaction channels populating excited ${}^{17}\mathrm{F}$ levels may significantly increase the calculated ${}^{14}\mathrm{O}(\alpha ,p){}^{17}\mathrm{F}$ reaction rate. A radioactive ${}^{17}\mathrm{F}$ beam was used at the Oak Ridge National Laboratory Holifield Radioactive Ion Beam Facility to search for a ${}^{18}\mathrm{Ne}$ resonance at ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}({}^{17}\mathit{F}+p)\simeq 3.1$ MeV that had been previously suggested to decay strongly to the first excited level in ${}^{17}\mathrm{F}$. No evidence, however, of inelastic ${}^{17}\mathit{F}+p$ scattering was observed at this energy, and an upper limit of $~$10 mb has been set on the inelastic-scattering cross section.

The transition density $n_t$ and pressure $P_t$ at the inner edge between the liquid core and the solid crust of a neutron star are analyzed using the thermodynamical method and the framework of relativistic nuclear energy density functionals. Starting from a functional that has been carefully adjusted to experimental binding energies of finite nuclei, and varying the density dependence of the corresponding symmetry energy within the limits determined by isovector properties of finite nuclei, we estimate the constraints on the core-crust transition density and pressure of neutron stars: $0.086\hspace{0.5em}{\mathrm{fm}}^{-3}⩽n_t<0.090\hspace{0.5em}{\mathrm{fm}}^{-3}$ and $0.3\hspace{0.5em}\mathrm{MeV}\hspace{0.5em}{\mathrm{fm}}^{-3}<P_t⩽0.76\hspace{0.5em}\mathrm{MeV}\hspace{0.5em}{\mathrm{fm}}^{-3}$.

In an ideal hydrodynamic model, with an equation of state where the confinement-deconfinement transition is a crossover at $T_{\mathit{co}}=196$ MeV, we have simulated $\sqrt{s}=200$ GeV Au$+$Au collisions. Simultaneous description of the experimental charged particle’s $p_T$ spectra and elliptic flow require that in central (0–$10\%$) Au$+$Au collisions, initial energy density scales with the binary collision number density. In less central collisions, experimental data demand scaling with the participant density. Simulation studies also indicate that in central collisions viscous effects are minimal.

A new method is presented for the calculation of the shell correction with the inclusion of the continuum part of the spectrum. The smoothing function used has a finite energy range in contrast to the Gaussian shape of the Strutinski method. The new method is especially useful for light nuclei where the generalized Strutinski procedure cannot be applied.