Eight new high spin states and 23 new γ transitions have been identified in ${}^{100}\mathrm{Zr}$ from studies of ${}^{252}\mathrm{Cf}$ spontaneous fission with Gammasphere. A near-spherical excited band in ${}^{100}\mathrm{Zr}$ based on the 331.1 keV $0^{+}$ state is extended from $4^{+}$ up to ${12}^{+}$. A $\Delta I=1$ band with band-head energy of 2316.1 keV is extended.

The Bohr-Mottelson model is solved for a generic soft triaxial nucleus, separating the Bohr Hamiltonian exactly and using a number of different model potentials: a displaced harmonic oscillator in γ, which is solved with an approximated algebraic technique; and Coulomb/Kratzer, harmonic/Davidson, and infinite square-well potentials in β, which are solved exactly. In each case we derive analytic expressions for the eigenenergies, which are then used to calculate energy spectra. Here we study the chain of osmium isotopes and compare our results with experimental information and previous calculations.

Excited states of $N=22$ ${}^{36}\mathrm{Si}$, populated in deep-inelastic processes produced by the interaction of a 215 MeV beam of ${}^{36}\mathrm{S}$ ions with a ${}^{208}\mathrm{Pb}$ target, were studied in the present work. γ rays from the binary fragments detected using CLARA, an array of 25 Ge Clover detectors, were measured in coincidence with projectile-like fragments detected by PRISMA, a large solid angle magnetic spectrometer. Two new γ-ray photopeaks at energies of 1442 and 842 keV were observed and tentatively assigned to the $4^{+}\to 2^{+}$ and $6^{+}\to 4^{+}$ transitions, respectively. The systematics of the level structures of $N=22$ isotones are presented, and a comparison is made of the behavior of Si, Mg, and S isotopes. The level structure of ${}^{36}\mathrm{Si}$ is also compared with the results of $\mathit{sdpf}$ shell model calculations.

Excitation functions for total reaction cross sections, ${\sigma }_R$, were measured for the light, mainly proton-rich nuclei ${}^6\mathrm{Li}$, ${}^7\mathrm{Be}$, ${}^{10}\mathrm{B}$, ${}^{9,10,11}\mathrm{C}$, ${}^{12}\mathrm{N}$, ${}^{13,15}\mathrm{O}$, and ${}^{17}\mathrm{Ne}$ incident on a Si telescope at energies between 15 and 53 MeV/nucleon. The telescope served as target, energy degrader and detector. Proton-removal cross sections, ${\sigma }_{2p}$ for ${}^{17}\mathrm{Ne}$ and ${\sigma }_p$ for most of the other projectiles, were also measured. The strong absorption model reproduces the $A$-dependence of ${\sigma }_R$, but not the detailed structure. Glauber multiple scattering theory and the Jeukenne, Lejeune, and Mahaux (JLM) folding model provided improved descriptions of the measured ${\sigma }_R$ values. Rms radii, extracted from the measured ${\sigma }_R$ using the optical limit of Glauber theory, are in good agreement with those obtained from high energy data. One-proton removal reactions are described using an extended Glauber model, incorporating second order noneikonal corrections, realistic single particle densities, and spectroscopic factors from shell model calculations.

The isovector dipole resonances (DR's) consisting of the giant dipole resonance and spin dipole resonance (SDR) in ${}^4\mathrm{He}$ were investigated by using the ($p,p^{\text{'}}$) reaction at an incident energy of 300 MeV. We compared the excitation energy, width, resonance shape and the differential cross sections for the DR in ${}^4\mathrm{He}$ with those for the DR's in ${}^6\mathrm{Li}$ and ${}^7\mathrm{Li}$ which had been observed and interpreted in earlier work as the DR's in the α clusters of ${}^6\mathrm{Li}$ and ${}^7\mathrm{Li}$. The DR's in ${}^4\mathrm{He}$ and in the α clusters of ${}^{6,7}\mathrm{Li}$ were observed at $E_x=25.1\pm 0.5,28.0\pm 0.5$, and $30.5\pm 0.5$ MeV with the widths of $11.0\pm 2.0,11.7\pm 1.5$, and $11.3\pm 2.0$ MeV, respectively. The peaks corresponding to the 2${}^{-}$ SDR in the α cluster were not as dominant as that observed in ${}^4\mathrm{He}$ at $E_x=22.1$ MeV. The resonance shapes for the α cluster in ${}^{6,7}\mathrm{Li}$ were reproduced well with the DR shape without including the 2${}^{-}$ SDR in ${}^4\mathrm{He}$. The excitation energies for the DR's in the α clusters slightly increase with the number of the surrounding nucleons. The cross sections for the excitation of the DR's in the α clusters of ${}^{6,7}\mathrm{Li}$, normalized to the spectroscopic factors for the α particle in ${}^{6,7}\mathrm{Li}$, are comparable to the cross section for the excitation of the DR in ${}^4\mathrm{He}$.

We study theoretically the kaonic atom and kaonic nucleus formations in the in-flight ($K^{-},p$) reactions using the Green function method, which is suited to evaluate formation rates both of stable and unstable bound systems. We consider ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ as the targets and calculate the spectra of the ($K^{-},p$) reactions. We conclude that no peak structure resulting from kaonic nucleus formation is expected in the reaction spectra calculated with the chiral unitary kaon-nucleus optical potential. In the spectra with the phenomenological deep kaon-nucleus potential, it may be possible to observe some structures because of the formation of the kaonic nucleus states. For all cases, we find clear signals because of the kaonic atom formations in the reaction spectra, which show very interesting structures, such as the RESONANCE DIP instead of the resonance peak for the atomic $1s$ state formation.

A quantitative understanding of isospin violation is an increasingly important ingredient in the extraction of the nucleon's strange vector form factors from experimental data. We calculate the isospin-violating electric and magnetic form factors in chiral perturbation theory to leading and next-to-leading order, and we extract the low-energy constants from resonance saturation. Uncertainties are dominated largely by limitations in the current knowledge of some vector meson couplings. The resulting bounds on isospin violation are sufficiently precise to be of value to on-going experimental studies of the strange form factors.

We have measured the beta-decay branching ratio for the transition from ${}^{21}\mathrm{Na}$ to the first excited state of ${}^{21}\mathrm{Ne}$. A recently published test of the standard model, which was based on a measurement of the $\beta \text{−}\nu$ correlation in the decay of ${}^{21}\mathrm{Na}$, depended on this branching ratio. However, until now only relatively imprecise (and, in some cases, contradictory) values existed for it. Our new result, $4.74(4)\%$, reduces but does not remove the reported discrepancy with the standard model.

Forward-backward correlations of charged-particle multiplicities in symmetric bins in pseudorapidity are studied to gain insight into the underlying correlation structure of particle production in Au+Au collisions. The PHOBOS detector is used to measure integrated multiplicities in bins centered at η, defined within $\left|\eta \right|<3$, and covering intervals $\Delta \eta$. The variance ${\sigma }_C^2$ of a suitably defined forward-backward asymmetry variable $C$ is calculated as a function of $\eta ,\Delta \eta$, and centrality. It is found to be sensitive to short-range correlations, and the concept of “clustering” is used to interpret comparisons to phenomenological models.

The observed signature splitting at high spin in the odd-odd isotopes ${}^{126-132}\mathrm{Pr}$ and its description in cranking calculations suggest that ${}^{126}\mathrm{Pr}$ ($Z=59,N=67$) is triaxially deformed at intermediate values. The triaxial shape is explained as caused by specific couplings between the orbitals. These couplings are active for $N=67$ but not for $N=69$.

The time-integrated luminosity and average energy of the neutrino emission spectrum are essential diagnostics of core-collapse supernovae. The SN 1987A electron antineutrino observations by the Kamiokande-II and IMB detectors are only roughly consistent with each other and theory. Using new measurements of the star formation rate history, we reinterpret the Super-Kamiokande upper bound on the electron antineutrino flux from all past supernovae as an excluded region in neutrino emission parameter space. A gadolinium-enhanced Super-Kamiokande should be able to jointly measure these parameters, and a future megaton-scale detector would enable precision studies.

The work of Müller et al. [Phys. Rev. C 73, 025804 (2006)] provides interesting experimental data on neutron emission by photodisintegration of ${}^{187}\mathrm{Re}$. However, the comparison to theory and the discussed implications for the Re/Os clock require considerable amendment.

The implementation of a number-conserving formalism for pair-addition and pair-removal modes has impaired the possibility of developing an intuitive and self-consistent picture for collective pairing modes. In this paper, we show how a relaxation of this constraint leads to a unified model with true predictive power.

The properties of the antikaons in nuclear matter are investigated from a chiral unitary approach which incorporates the $s$- and $p$-waves of the $\overline{K}N$ interaction. To obtain the in-medium meson-baryon amplitudes we include, in a self-consistent way, Pauli blocking effects, meson self-energies corrected by nuclear short-range correlations and baryon binding potentials. We pay special attention to investigating the validity of the on-shell factorization, showing that it cannot be applied in the evaluation of the in-medium corrections to the $p$-wave amplitudes. In nuclear matter at saturation energy, the Λ and Σ develop an attractive potential of about −30 MeV, while the ${\Sigma }^{*}$ pole remains at the free space value although its width gets sensibly increased to about 80 MeV. The antikaon also develops a moderate attraction that does not support the existence of very deep and narrow bound states, confirming the findings of previous self-consistent calculations.

Using the relativistic version of Landau theory of Fermi liquid with $\sigma \text{−}\omega$ and ρ mesons exchange, we have obtained an equation state for dense neutron star matter in the presence of a strong, quantizing magnetic field. It is found that in this scenario the self-energies of both neutron and proton components of dense neutron star matter become complex under certain physical conditions. To be more specific, it is observed that in the exchange diagrams of $\sigma ,\omega$ and neutral ρ transfer processes and in the direct interaction diagram with ${\rho }_{\pm }$ transfer reactions, the nucleon self-energies become complex in nature.

Rates for the ${}^4\mathrm{He}$$(2n,\gamma )$${}^6\mathrm{He}$ and ${}^6\mathrm{He}$$(\alpha ,n)$${}^9\mathrm{Be}$ reactions have been calculated, including both resonant and nonresonant contributions. The sequential two-neutron capture process on ${}^4\mathrm{He}$ has also been reevaluated on the basis of new experimental results. It is shown that a one-step dineutron capture reaction may enhance the sequential two-neutron reaction rate by several orders of magnitude. This opens the possibility that reaction flow through ${}^4\mathrm{He}$$({}^{2}n,\gamma )$${}^6\mathrm{He}$$(\alpha ,n)$${}^9\mathrm{Be}$ may occur in competition with the bottle-neck three-body reactions ${}^4\mathrm{He}$(2$\alpha ,\gamma )$${}^{12}\mathrm{C}$ and the ${}^4\mathrm{He}$$(\alpha n,\gamma )$${}^9\mathrm{Be}$ that initiate the α process and provide seed nuclei for the $r$ process. Here we explore the effect of such dineutron capture on $r$-process nucleosynthesis. We show that such reactions have little effect on the final abundance and would change only $r$-process abundances in an extremely neutron-rich low-temperature $r$ process.

We performed self-consistent Green's function calculations for symmetric nuclear matter using realistic nucleon-nucleon ($\mathit{NN}$) interactions and effective low-momentum interactions ($V_{\mathrm{low}-k}$), which are derived from such realistic $\mathit{NN}$ interactions. We compare the spectral distributions resulting from such calculations. We also introduce a density-dependent effective low-momentum interaction that accounts for the dispersive effects in the single-particle propagator in the medium.

A global calculation of favored α-decay half-lives of both even-$A$ and odd-$A$ deformed nuclei is carried out in the framework of a deformed version of the density-dependent cluster model (DDCM). The influence of nuclear deformation on α-decay half-lives is taken into account in the deformed DDCM. The microscopic potential between the spherical α particle and the deformed daughter nucleus is evaluated numerically from the double-folding model by the multipole expansion method. The deformation and orientation dependence of the α-core potential is analyzed and discussed. The formulas of the deformed DDCM are presented in detail, and a large number of numerical calculations of medium and heavy nuclei with available data are completed. The total number of α emitters calculated in this article is 485, and this covers the nuclei with $Z=52\text{−}110$. This is a complete study of α-decay half-lives on both even-$A$ and odd-$A$ nuclei with deformed microscopic potentials. The numerical results obtained by the deformed DDCM are in good agreement with the experimental data.

High-spin states in ${}^{124}\mathrm{Ba}$ were investigated in two experiments using the ${}^{64}\mathrm{Ni}$(${}^{64}\mathrm{Ni}$, $4n$)${}^{124}\mathrm{Ba}$ reaction at three different beam energies. In-beam γ-ray coincidences were measured with the Euroball and Gammasphere detector arrays. In the experiment with Euroball, the CsI detector array Diamant was employed to discriminate against charged-particle channels. Six new rotational bands were observed in ${}^{124}\mathrm{Ba}$, and previously known bands were extended to higher spins. One of the bands shows a transition from collective to noncollective behavior at high spins. Configuration assignments are suggested on the basis of comparison with cranked shell model and cranked Nilsson-Strutinsky calculations.