Excited states have been identified in the very neutron-deficient $Z=58$ nucleus ${}^{123}$Ce. This is the most neutron-deficient odd-$A$ cerium isotope in which excited states have been identified. The states have been unambiguously assigned to ${}^{123}$Ce by detecting de-excitation $\gamma$ rays in coincidence with evaporated charged particles and neutrons. Three rotational bands, each consisting of at least eight $E2$ transitions, have been observed. The bands have tentatively been assigned to be based on neutrons in $g_{7/2}$ and $h_{11/2}$ orbitals. Two of the bands have been assigned to be signature partners, although no interband transitions have been observed. The aligned angular momenta of the bands have been studied in comparison with neighboring nuclei and with the results of Woods-Saxon cranking calculations. Observation of the deformation-dependent $\pi {\left(h_{11/2}\right)}^2$ quasiparticle alignment at 0.36 MeV/$\hslash$ in each of the bands suggests a quadrupole deformation of ${\beta }_2\simeq 0.3$, in good agreement with theoretical predictions for the suggested possible configuration assignments.

An experimental study of the ${}^{62}$Zn nucleus has been performed by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previously published data, the present results include ten new rotational band structures and two more superdeformed bands. The Gammasphere Ge-detector array in conjunction with the 4$\pi$ charged-particle detector array Microball allowed for the detection of $\gamma$ rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with more than 450 $\gamma$-ray transitions. Spins and parities of the excited states have been determined via directional correlations of $\gamma$ rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with results from cranked Nilsson-Strutinsky calculations. The present analysis, combined with available experimental results in the $A\sim 60$ mass region, can be used to improve the current set of Nilsson parameters in the $\mathcal{N}=3$ and $\mathcal{N}=4$ oscillator shells.

An analysis of the elastic and exclusive breakup of ${}^{17}$F on ${}^{58}$Ni and ${}^{208}$Pb targets is presented. The study is undertaken using the continuum-discretized coupled-channels (CDCC) method, assuming a core+valence model for the ${}^{17}$F projectile. The results are compared with recent data published for these reactions [Phys. Lett. B 681, 22 (2009)]. The calculations show that the exclusive breakup cross sections contain contributions from high multipoles, as well as a complicated interplay between Coulomb and nuclear couplings. This makes it difficult to extract radiative capture cross sections or structure information from the analyzed data.

We use a Monte Carlo approach to study hadron azimuthal angular correlations in high-energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider energies at midrapidity. We build a hadron event generator that incorporates the production of $2\to 2$ and $2\to 3$ parton processes and their evolution into hadron states. For nucleus-nucleus collisions we include the effect of parton energy loss in the quark-gluon plasma using a modified fragmentation function approach. In the presence of the medium, for the case when three partons are produced in the hard scattering, we analyze the Monte Carlo sample in parton and hadron momentum bins to reconstruct the angular correlations. We characterize this sample by the number of partons that are able to hadronize by fragmentation within the selected bins. In the nuclear environment the model allows hadronization by fragmentation only for partons with momentum above a threshold $p_T^{\text{thresh}}=2.4$ GeV. We argue that one should treat properly the effect of those partons with momentum below the threshold, because their interaction with the medium may lead to showers of low-momentum hadrons along the direction of motion of the original partons as the medium becomes diluted.

We propose that flow fluctuations have the same origin as transverse momentum fluctuations. The common source of these fluctuations is the spatially inhomogeneous initial state that drives hydrodynamic flow. Longitudinal correlations from an early Glasma stage followed by hydrodynamic flow quantitatively account for many features of multiplicity and $p_t$ fluctuation data. We develop a framework for studying flow and its fluctuations in this picture. We then compute elliptic and triangular flow fluctuations and study their connections to the ridge.

We perform an analytic and numerical study of parametric resonance in a three-neutrino framework for sub-GeV neutrinos which travel through a periodic density profile. Commensurate with the initial level of approximation, we develop a parametric resonance condition similar to the exact condition for two-neutrino systems. For a castle-wall density profile, the ${\nu }_e\to {\nu }_{\mu }$ oscillation probability is enhanced significantly and bounded by ${\cos }^2{\theta }_{23}$. The $CP$ phase $\delta$ enters into the oscillation probability as a phase shift. For several cases, we examine the interplay between the characteristics of the castle-wall profile and the $CP$ phase and determine which profiles maximize the separation between oscillations with $\delta =0,\pm \frac{\pi }{2},\pi$. We also consider neutrinos which travel along a chord through the Earth, passing from the mantle to core and back to mantle again. Significant enhancement of the oscillation probability is seen even in the case in which the neutrino energy is far from the MSW resonant energies. At 500 GeV, the difference between oscillation probabilities with $\delta =0$ and $\delta =\frac{\pi }{2}$ is maximized.

We study the incoherent neutrinoproduction of photons and pions with neutrino energy $E_{\nu }⩽0.5\mathrm{GeV}$. These processes are relevant to the background analysis in neutrino-oscillation experiments [for example, MiniBooNE; A. A. Aquilar-Arevalo et al. (MiniBooNE Collaboration), Phys. Rev. Lett. 100, 032301 (2008)]. The calculations are carried out using a Lorentz-covariant effective field theory (EFT), which contains nucleons, pions, the Delta (1232) ($\Delta$), isoscalar scalar ($\sigma$) and vector ($\omega$) fields, and isovector vector ($\rho$) fields, and has $\mathrm{SU}{\left(2\right)}_{\mathrm{L}}\otimes \mathrm{SU}{\left(2\right)}_{\mathrm{R}}$ chiral symmetry realized nonlinearly. The contributions of one-body currents are studied in the local Fermi gas approximation. The current form factors are generated by meson dominance in the EFT Lagrangian. The conservation of the vector current and the partial conservation of the axial current are satisfied automatically, which is crucial for photon production. The $\Delta$ dynamics in nuclei, as a key component in the study, is explored. Introduced $\Delta$-meson couplings explain the $\Delta$ spin-orbit coupling in nuclei, and this leads to interesting constraints on the theory. Meanwhile, a phenomenological approach is applied to parametrize the $\Delta$ width. To benchmark our approximations, we calculate the differential cross sections for quasielastic scattering and incoherent electroproduction of pions without a final-state interaction (FSI). The FSI can be ignored for photon production.

Background: The $\gamma$ process in core-collapse supernova explosions is thought to explain the origin of proton-rich isotopes between Se and Hg, the so-called $p$ nuclei. The majority of the reaction rates for $\gamma$ process reaction network studies has to be predicted in Hauser-Feshbach statistical model calculations. Recent investigations have shown problems in the prediction of $\alpha$ widths at astrophysical energies. This impacts the reliability of abundance predictions in the upper mass range of the $p$ nuclei.

Purpose: Our purpose is to measure the ${}^{127}$I($\alpha$,$\gamma$)${}^{131}$Cs and ${}^{127}$I($\alpha$,n)${}^{130}$Cs reaction cross sections close to the astrophysically relevant energy range to test the predictions, to derive an improved reaction rate, and to extend the database required to define an improved global optical $\alpha$+nucleus potential.

Methods: The cross sections are derived using the activation technique and the yield of the emitted $\gamma$, and characteristic x-ray photons are measured using a LEPS and an HPGe detector.

Results: Cross sections of the ${}^{127}$I($\alpha$,$\gamma$)${}^{131}$Cs reaction are determined for the first time, at energies $9.50⩽E_{\mathrm{c}.\mathrm{m}.}⩽15.15$ MeV. The ${}^{127}$I($\alpha$,n)${}^{130}$Cs reaction is studied in the range $9.62⩽E_{\mathrm{c}.\mathrm{m}.}⩽15.15$ MeV. Furthermore, the relative intensity of the 536.1-keV $\gamma$ transition is measured precisely; its uncertainty is reduced from 13$\%$ to 4$\%$. The results are then compared to Hauser-Feshbach calculations which are also used to extend the cross sections into the astrophysically relevant region and to compute the reaction rate.

Conclusions: The comparison to statistical Hauser-Feshbach model calculations shows that the $\alpha$ width can be described well in the measured energy range using a standard, energy-independent global optical potential. The newly derived stellar reaction rates at $\gamma$ process temperatures for ${}^{127}$I($\alpha$,$\gamma$)${}^{131}$Cs and its reverse reactions, nevertheless, are faster by factors of 4–10 than those from previous calculations, owing to further improvements in the reaction model. The importance of the inclusion of complete level schemes in the Hauser-Feshbach calculations is illustrated by comparing the impacts of two level schemes, one of them extending to higher excitation energies but not containing all relevant levels.

In heavy ion collisions, event-by-event fluctuations in participating nucleon positions can lead to triangular flow. Generally, one uses a Monte Carlo Glauber model to obtain the participating nucleon positions. To use these positions in a hydrodynamic model, it needs to be smoothed. We studied the effect of smoothing of Glauber Monte Carlo initial conditions on elliptic and triangular flow. It is shown that integrated as well as differential elliptic and triangular flows remain largely unaltered, irrespective of functional form of the smoothing function, or the smoothing parameter.

The low-energy nuclear structure of the neutron-rich ${}^{43-46}$Cl isotopes is studied via in-beam $\gamma$-ray spectroscopy following the fragmentation of ${}^{48}$K projectiles on a ${}^9$Be target at intermediate beam energies. $\gamma \gamma$ coincidence information was used to construct level schemes for these neutron-rich nuclei. For the $N=28$ nucleus ${}^{45}$Cl, the lifetime of the first excited state at 130 keV was extracted via $\gamma$-ray line shape analysis, yielding an $M1$ strength an order of magnitude greater than that predicted by theory. The experimental data is compared to the results of large-scale shell-model calculations with effective interactions in the $sd$-$pf$ model space.

A systematic analysis is made on the total reaction cross sections for Ne, Mg, Si, and S isotopes. The high-energy nucleus-nucleus collision is described based on the Glauber model. Using the Skyrme-Hartree-Fock method in the three-dimensional grid-space representation, we determine the nuclear density distribution for a wide range of nuclei self-consistently without assuming any spatial symmetry. The calculated total reaction cross sections consistently agree with the recent cross section data on the Ne${+}^{12}$C collision at 240 $A$MeV, which makes it possible to discuss the radius and deformation of the isotopes. The total reaction cross sections for Mg${+}^{12}$C, Si${+}^{12}$C, and S${+}^{12}$C cases are predicted for future measurements. We also find that the high-energy cross section data for O, Ne, and Mg isotopes on a ${}^{12}$C target at around 1000 $A$MeV can not be reproduced consistently with the corresponding data at 240 $A$MeV.

The behaviors of barrier characteristics and fusion cross sections are analyzed by changing neutrons over a wide range of colliding systems. For this purpose, we have extended our previous study [Ghodsi and Gharaei, Eur. Phys. J. A 48, 21 (2012), it is devoted to the colliding systems with neutron-rich nuclei] to 125 isotopic systems with the condition of $0.5⩽N/Z⩽1.6$ for their compound nuclei. The AW 95, Bass 80, Denisov DP, and Prox. 2010 potentials are used to calculate the nuclear part of the interacting potential. The obtained results show that the trend of barrier heights $V_B$ and positions $R_B$ as well as nuclear $V_N$ and Coulomb $V_C$ potentials (at $R=R_B$) as a function of ($N/Z-1$) quantity are nonlinear (second order) whereas the fusion cross sections follow a linear dependence.

Background. Good understanding of the cross sections for (anti)neutrino scattering off nuclear targets in the few-GeV energy region is a prerequisite for the correct interpretation of results of ongoing and planned oscillation experiments.

Purpose. Clarify a possible source of disagreement between recent measurements of the cross sections on carbon.

Method. Nuclear effects in (anti)neutrino scattering off carbon nucleus are described using the spectral function approach. The effect of two- and multinucleon final states is accounted for by applying an effective value of the axial mass, fixed to 1.23 GeV. Neutral-current elastic (NCE) and charged-current quasielastic (CCQE) processes are treated on equal footing.

Results. The differential and total cross sections for the energy ranging from a few hundreds of MeV to 100 GeV are obtained and compared to the available data from the BNL E734, MiniBooNE, and NOMAD experiments.

Conclusions. Nuclear effects in NCE and CCQE scattering seem to be very similar. Within the spectral function approach, the axial mass from the shape analysis of the MiniBooNE data is in good agreement with the results reported by the BNL E734 and NOMAD Collaborations. However, the combined analysis of the NCE and CCQE data does not seem to support the contribution of multinucleon final states being large enough to explain the normalization of the MiniBooNE-reported cross sections.

The phase diagram of a system constituted of neutrons and $\Lambda$ hyperons in thermal equilibrium is evaluated in the mean-field approximation. It is shown that this simple system exhibits a complex phase diagram with first- and second-order phase transitions. Due to the generic presence of attractive and repulsive couplings, the existence of phase transitions involving strangeness appears independent of the specific interaction model. In addition we will show under which conditions a phase transition towards strange matter at high density exists, which is expected to persist even within a complete treatment including all the different strange and nonstrange baryon states. The impact of this transition on the composition of matter in the inner core of neutron stars is discussed.

A novel method to determine the density and temperature of a system based on quantum Fermionic fluctuations is generalized to the limit where the reached temperature $T$ is large compared to the Fermi energy ${\varepsilon }_f$. Quadrupole and particle multiplicity fluctuation relations are derived in terms of $\frac{T}{{\varepsilon }_f}$. The relevant Fermi integrals are numerically solved for any values of $\frac{T}{{\varepsilon }_f}$ and compared to the analytical approximations. The classical limit is obtained, as expected, for large temperatures and low densities. The entropy can also be easily derived from quantum fluctuations and gives important insight into the behavior of the system near a phase transition.

We present the first applications of the second random-phase-approximation model with the finite-range Gogny interaction. We discuss the advantages of using such an interaction in this type of calculations where two-particle–two-hole configurations are included. The results found in the present work confirm the well-known general features of the second random-phase approximation spectra: We find a large shift, several MeV, of the response centroids to lower energies with respect to the corresponding random-phase-approximation values. As known, these results indicate that the effects of the one-particle–one-hole/two-particle–two-hole and two-particle–two-hole/two-particle–two-hole couplings are important. It has been found that the changes of the strength distributions with respect to the standard random-phase-approximation results are particularly large in the present case. This important effect is due to some large neutron-proton matrix elements of the interaction and indicates that these matrix elements (which do not contribute in the mean-field calculations employed in the conventional fit procedures of the force parameters) should be carefully constrained to perform calculations beyond the mean-field approach.

The astrophysical factor of ${}^8$B($p$,$\gamma$)${}^9$C at zero energy, $S_{18}\left(0\right)$, is determined from three-body model analysis of ${}^9$C breakup processes. The elastic breakup reaction ${}^{208}$Pb(${}^9$C,$p{}^8$B)${}^{208}$Pb at 65 MeV/nucleon and the one-proton removal reaction of ${}^9$C at 285 MeV/nucleon on C and Al targets are calculated with the continuum-discretized coupled-channels method (CDCC) and the eikonal reaction theory (ERT), respectively. The asymptotic normalization coefficient (ANC) of ${}^9$C in the $p$-${}^8$B configuration, $C_{p{}^8\text{B}}^{{}^9\text{C}}$, extracted from the two reactions shows good consistency, unlike in previous studies. As a result of the present analysis, $S_{18}\left(0\right)=66\pm 10\mathrm{eVb}$ is obtained.