Low-lying states for doubly-odd nuclei in the mass $A\sim 130$ region are investigated using a pair-truncated shell model. Energy levels of the low-lying states for doubly-odd nuclei, ${}^{132}$Cs, ${}^{130}$Cs, ${}^{134}$La, and ${}^{132}$La, are reproduced very well along with the electromagnetic transitions. The analysis of the wave functions reveals band structure for doublet bands built on the $\nu h_{11/2}\otimes \pi h_{11/2}$ configuration, showing various angular-momentum configurations of the unpaired neutron and the unpaired proton, weakly coupled with the quadrupole collective excitations of the even-even part of the nucleus.

High spin states in ${}^{108}$Ag have been studied via in-beam $\gamma$ spectroscopy techniques using the ${}^{104}$Ru(${}^7$Li, $3n$) reaction. The previously known level scheme has been extended, and a new band structure has been established. The configurations have been tentatively assigned to all observed rotational bands. The signature splitting behavior of the $\pi g_{9/2}\otimes \nu g_{7/2}$ band has been discussed and interpreted as a change in shape from near-oblate to prolate. A systematic study of the nearly degenerate negative-parity bands in the $A\sim 110$ mass region has been performed and it is found that the yrast band in ${}^{108}$Ag and its side band show different behaviors with those expected from a pair of chiral bands.

Neutron evaporation spectra at backward angles from ${}^{201}$Tl${}^{*}$, ${}^{185}$Re${}^{*}$, and ${}^{169}$Tm${}^{*}$ compound nuclei, having different ground-state deformations, have been measured at two excitation energies ($E^{*}$ $\sim$ 37 and 26 MeV). The values of the inverse level density parameter ($k$), extracted at these excitations using statistical model calculations, are observed to decrease substantially at the lower excitation energy ($\sim$26 MeV) for nuclei having large ground-state deformation (residues of ${}^{185}$Re${}^{*}$ and ${}^{169}$Tm${}^{*}$), whereas for near-spherical nuclei (residues of ${}^{201}$Tl${}^{*}$), the $k$ value remains unchanged at the two energies. The decrease in $k$ at the lower excitation energy for the deformed systems amounts to a relative increase in nuclear level density, indicating a collective enhancement. The present observation clearly establishes the existence of a strong correlation between collectivity and ground-state deformation.

The very neutron-rich oxygen isotopes ${}^{25}$O and ${}^{26}$O are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from ${}^{26}$F and ${}^{27}$F at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into ${}^{24}$O plus one or two neutrons, the ${}^{25}$O ground-state energy and width are determined, and upper limits for the ${}^{26}$O ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in ${}^{26}$O at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon ($3N$) forces, including for the first time residual $3N$ forces, which are shown to be amplified as valence neutrons are added.

Exotic and drip-line nuclei as well as nuclei immersed in a low-density gas of neutrons in the inner crust of neutron stars are systematically investigated with respect to their neutron pairing properties. This is done using Skyrme density-functional and different pairing forces such as a density-dependent contact interaction and a separable form of a finite-range Gogny interaction. Hartree-Fock-Bogoliubov (HFB) and Bardeen-Cooper-Schrieffer (BCS) theories are compared. It is found that neutron pairing is reduced towards the drip line while overcast by strong shell effects. Furthermore, resonances in the continuum can have an important effect counterbalancing the tendency of reduction and leading to a persistence of pairing at the drip line. It is also shown that in these systems the difference between HFB and BCS approaches can be quantitatively large.

The $K$ hindrance to the $\gamma$ decay is studied in the warm rotating ${}^{174}$W nucleus, focusing on the weakening of the selection rules of the $K$ quantum number with increasing excitation energy. ${}^{174}$W was populated by the fusion reaction of ${}^{50}$Ti (at 217 MeV) on a ${}^{128}$Te target, and its $\gamma$ decay was detected by the AGATA Demonstrator array coupled to a BaF${}_2$ multiplicity filter at Laboratori Nazionali di Legnaro of INFN. A fluctuation analysis of $\gamma$ coincidence matrices gives a similar number of low-$K$ and high-$K$ discrete excited bands. The results are compared to simulations of the $\gamma$-decay flow based on a microscopic cranked shell model at finite temperature in which the $K$ mixing is governed by the interplay of Coriolis force with the residual interaction. Agreement between simulations and experiment is obtained only by hindering the $E1$ decay between low-$K$ and high-$K$ bands by an amount compatible with that determined by spectroscopic studies of $K$ isomers in the same mass region, with a similar trend with excitation energy. The work indicates that $K$ mixing due to temperature effects may play a leading role for the entire body of discrete excited bands, which probes the onset region of $K$ weakening.

We predict the polarization of $\Lambda$ and $\overline{\Lambda }$ hyperons in peripheral heavy ion collisions at ultrarelativistic energy, based on the assumption of local thermodynamical equilibrium at the freeze-out. The polarization vector is proportional to the curl of the inverse temperature four-vector field and its length, of the order of percents, is maximal for a particle with moderately high momentum lying on the reaction plane. A selective measurement of these particles could make $\Lambda$ polarization detectable.

We investigate the two-body reactions $\overline{K}N\to \overline{K}N$, $\overline{K}N\to \pi \Lambda$, and $\overline{K}N\to \pi \Sigma$ via single-energy partial-wave analyses in the center-of-mass (c.m.) energy range 1480 to 2100 MeV. The partial-wave amplitudes for these reactions thus extracted were constrained by a multichannel energy-dependent model satisfying unitarity of the partial-wave $S$ matrix. We obtain excellent predictions of differential cross sections, polarizations, polarized cross sections, and cross sections for these reactions from a global energy-dependent solution.

We present results of a new multichannel partial-wave analysis for $\overline{K}N$ scattering in the center-of-mass (c.m.) energy range from 1480 to 2100 MeV. Resonance parameters were extracted by fitting partial-wave amplitudes from all considered channels using a multichannel parametrization that is consistent with $S$-matrix unitarity. The resonance parameters are generally in good agreement with predictions of the Koniuk-Isgur quark model.

Penning-trap mass spectrometry was used at the Low-Energy Beam and Ion Trap (LEBIT) facility at the National Superconducting Cyclotron Laboratory (NSCL) to investigate ${}^{78}$Kr, a candidate for resonantly enhanced neutrinoless double-electron capture (0$\nu$ECEC). The newly determined $Q$ value of 2847.75 (27) keV is 1.4 keV greater than the value from the most recent atomic mass evaluation [Chin. Phys. C 36, 1603 (2012)], a change of two sigma, and the uncertainty has been reduced by a factor of three. The change in the $Q$ value shifts allowed 0$\nu$ECEC in ${}^{78}$Kr further from resonant enhancement. With the improved determination of the $Q$ value, all known excited states can now be confidently excluded from possible ${}^{78}$Se candidates that could lead to resonantly enhanced 0$\nu$ECEC.

The effect of strong magnetic fields on the properties of the pasta structure is calculated within a Thomas-Fermi approach using relativistic mean-field models to modulate stellar matter. It is shown how quantities such as the size of the clusters and Wigner-Seitz cells, the surface tension, and the transition between configurations are affected. It is expected that these effects may give rise to large stresses in the pasta phase if the local magnetic field suffers fluctuations.

The excitation energies of the primary hot isotopes in multifragmentation events are experimentally reconstructed in the reaction system ${}^{64}$Zn $+$ ${}^{112}$Sn at 40 MeV/nucleon. A kinematical focusing method is employed to evaluate the multiplicities of the evaporated light particles associated with isotopically identified fragments with $3\le Z\le 14$. Angular distributions of the velocity spectra of light charged particles and neutrons associated with trigger isotopes are examined. A moving source fit is used to separate the kinematically correlated particles, evaporated from the parents of the detected isotopes, from the uncorrelated particles originating from other sources. The latter are evaluated experimentally relative to those in coincidence with the Li isotopes. A parameter, $k$, is used to adjust the yield of the uncorrelated particles for different trigger isotopes. For each experimentally detected isotope, the multiplicities, apparent temperatures, and $k$ values for $n$, $p$, $d$, $t$, and $\alpha$ particles are extracted. Using the extracted values, the excitation energies of the primary hot isotopes are reconstructed employing a Monte Carlo method. The extracted excitation energies are in the range of 1 to 4 MeV/nucleon but show a significant decreasing trend as a function of $A$ for a given $Z$ of the isotopes. The results are compared with those of antisymmetrized molecular dynamics (AMD) and statistical multifragmentation model (SMM) simulations. While some of the experimental characteristics are predicted partially by each model, neither simulation reproduces the overall characteristics of the experimental results.

We investigate properties of the probability distribution of the net quark number near the chiral crossover transition in the quark-meson model. The calculations are performed within the functional renormalization group approach, as well as in the mean-field approximation. We find that there is a substantial influence of the underlying chiral phase transition on the properties of the probability distribution. In particular, for a physical pion mass, the distribution which includes the effect of mesonic fluctuations, differs considerably from both, the mean-field and Skellam distributions. The latter is considered as a reference for a noncritical behavior. A characteristic feature of the net quark number probability distribution is that, in the vicinity of the chiral crossover transition in the $O\left(4\right)$ universality class, it is narrower than the corresponding mean-field and Skellam function. We study the volume dependence of the probability distribution, as well as the resulting cumulants, and discuss their approximate scaling properties.

We study the transverse momentum spectrum and the elliptic flow $v_2$ of photons produced in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV using the parton-hadron-string dynamics (PHSD) transport approach. As sources for photon production, we incorporate the interactions of off-shell quarks and gluons in the strongly interacting quark-gluon plasma (sQGP) [$q+\overline{q}\to g+\gamma$ and $q\left(\overline{q}\right)+g\to q\left(\overline{q}\right)+\gamma$], the decays of hadrons ($\pi \to \gamma +\gamma$, $\eta \to \gamma +\gamma$, $\omega \to \pi +\gamma$, ${\eta }^{\prime }\to \rho +\gamma$, $\varphi \to \eta +\gamma$, $a_1\to \pi +\gamma$) as well as their interactions ($\pi +\pi \to \rho +\gamma$, $\rho +\pi \to \pi +\gamma$, meson-meson bremsstrahlung $m+m\to m+m+\gamma$). The PHSD calculations reproduce the transverse momentum spectrum, the effective temperature $T_{\mathrm{eff}}$ and the elliptic flow $v_2$ of both inclusive and direct photons as measured by the PHENIX Collaboration. The photons produced in the QGP contribute slightly less then 50% to the observed spectrum, but have small $v_2$. We find that the large direct photon $v_2$—comparable to that of hadrons—can be attributed to the intermediate hadronic scattering channels not subtracted from the data when following the same extraction procedure for $v_2$ as in the PHENIX experiment. On the other hand the $v_2$ of direct photons—as evaluated by the weighted average of direct photon channels—gives a lower signal. The difference between the two extraction procedures for the direct photon $v_2$ can be attributed to different definitions for the yield ratio of direct photons to the background photons. The QGP phase causes the strong elliptic flow of photons indirectly, by enhancing the $v_2$ of final hadrons due to the partonic interaction in terms of explicit parton collisions and the mean-field potentials. We also show that the presence of the QGP radiation is manifest in the slope of the direct photon spectrum, leading to an effective slope parameter $T_{\mathrm{eff}}$ far above the critical temperature for the deconfinement phase transition.

Finding out the universal conditions describing the freeze-out parameters has been the subject of various phenomenological studies. In the present work, we introduce a new condition based on constant-trace anomaly (or interaction measure) calculated in the hadron resonance gas (HRG) model. Various extensions to the ideal HRG which are conjectured to take into consideration different types of interactions have been analyzed. When comparing HRG thermodynamics to that of lattice quantum chromodynamics, we conclude that the hard-core radii are practically irrelevant, especially when HRG includes all resonances with masses less than 2 GeV. It is found that the constant-trace anomaly (or interaction measure) agrees well with most previous conditions.

A search for excited $0^{+}$ states in ${}^{62}$Zn was conducted via the ${}^{64}$Zn($p,t$)${}^{62}$Zn reaction. Four such states in ${}^{62}$Zn were observed up to an excitation energy of 5.4 MeV. The measured angular distribution for the previously assigned $0_2^{+}$ state at 2342 keV is consistent with a $2^{+}$ assignment, and thus the first excited $0^{+}$ state is now assigned at 3043 keV. Due to the energy scaling in the currently adopted formalism for isospin-mixing corrections in superallowed Fermi $\beta$ decay, ${\delta }_{C1}$ for ${}^{62}$Ga is reduced by nearly a factor of two. This result shifts the theoretical value closer to previous experimental determinations of the same quantity through ${}^{62}$Ga superallowed $\beta$-decay branching-ratio measurements.

Background: For cranked mean-field calculations with arbitrarily oriented rotational frequency vector $\omega$ in the intrinsic frame, one has to employ constraints on average values of the quadrupole-moment tensor, so as to keep the nucleus in the principal-axis reference frame. Kerman and Onishi [Nucl. Phys. A 361, 179 (1981)] have shown that the Lagrange multipliers that correspond to the required constraints are proportional to $\omega \times \mathbf{J}$, where $\mathbf{J}$ is the average angular momentum vector.

Purpose: We study the validity and consequences of the Kerman-Onishi conditions in the context of self-consistent tilted-axis-cranking (TAC) mean-field calculations.

Methods: We perform self-consistent two-dimensional-cranking calculations (with and without pairing) utilizing the symmetry-unrestricted solver hfodd. At each tilting angle, we compare the calculated values of quadrupole-moment-tensor Lagrange multipliers and $\omega \times \mathbf{J}$.

Results: We show that in self-consistent calculations, the Kerman-Onishi conditions are obeyed with high precision. Small deviations seen in the calculations with pairing can be attributed to the truncation of the quasiparticle spectrum. We also provide results of systematic TAC calculations for triaxial strongly deformed bands in ${}^{160}$Yb.

Conclusions: For nonstationary TAC solutions, Kerman-Onishi conditions link the nonzero values of the angle between rotational-frequency and angular-momentum vectors to the constraints on off-diagonal components of the quadrupole-moment tensor. To stabilize the convergence of self-consistent iterations, such constraints have to be taken into account. Only then one can determine the Routhian surfaces as functions of the tilting angles.

The inelastic scattering of neutrons on ${}^{28}$Si was investigated using the ($n,n^{\prime }\gamma$) technique. The $\gamma$ production cross sections were measured and the level and total inelastic cross sections were determined with high accuracy. ${}^{28}$Si was also excited through the ${}^{25}$Mg($\alpha ,n\gamma$)${}^{28}$Si reaction and a comparison of the $\gamma$ production cross sections determined for various incident energies was performed.

A recent paper [Phys. Rev. C 86, 024310 (2012)] that concerned ${}^{12}$Be suggested $J^{\pi }$ of 0${}^{+}$ and 1${}^{-}$ for known states at energies of 0.89 and 2.03 MeV, respectively, above the 2$n$ threshold. I argue that their most likely assignments are 3${}^{-}$ and 4${}^{+}$, respectively, and that the measured 2$n$ transfer cross sections for the two known states are 20 to 50 times as large as those expected for the 0${}^{+}$ and 1${}^{-}$ states of Garrido et al.

We suggested that the two resonances at $0.89$ and $2.03$ MeV above the two-neutron separation threshold have spins and parities of $0^{+}$ and $1^{-}$. In the Comment, Fortune claims that these states almost unambiguously must be $3^{-}$ and $4^{+}$ states. We work in three-body cluster models with $J^{\pi }=0^{+},1^{-},2^{+}$ where all three-body continuum structures are included. Fortune bases his assignments on the bound-state shell-model and $(t,p)$ calculations. Our conclusions are from three-body structure results including widths. Assignments as $0^{+}$ and $1^{-}$ (or, perhaps, $3^{-}$) resonances are the most natural within the three-body cluster model.