By using a viscous hydrodynamic model coupled to a hadronic cascade code, numerous features of the dynamics and equilibrium properties are explored for their impact on femtoscopic measurements. The equation of state, viscous parameters, and initial conditions are investigated. We find that femtoscopy is affected by numerous model features at the 10% level and that by including features and adjusting unknown parameters, one can explain experimental source size measurements to better than 10%.

We searched for the neutrino-less double-$\beta$ decay($0\nu \beta \beta$) of ${}^{48}\mathrm{Ca}$ by using ${\mathrm{CaF}}_2$(Eu) scintillators. Analysis of their pulse shapes was effective to reduce backgrounds. No events are observed in the $Q_{\beta \beta }$ value region for the data of 3394 kg · day. It gives a lower limit (90% confidence level) of $T_{1/2}^{0\nu \beta \beta }>2.7\times {10}^{22}$ year for the half-life of $0\nu \beta \beta$ of ${}^{48}\mathrm{Ca}$. Combined with our previous data for 1553 kg · day [I. Ogawa et al., Nucl. Phys. A730, 215 (2004)], we obtained a more stringent limit of $T_{1/2}^{0\nu \beta \beta }>5.8\times {10}^{22}$ year.

A new procedure to construct hyperspherical harmonics is presented in which the matrix of the multidimensional hyperangular Laplacian is diagonalized in the single-particle oscillator basis. It is shown that this matrix can be constructed and diagonalized prior to the elimination of spurious states in small subspaces, and that calculations of only the two-body operators is required. As a result, the hyperspherical basis can be constructed much faster than in the procedure introduced earlier [N. K. Timofeyuk, Phys. Rev. C 65, 064306 (2002)], which is based on recursive elimination of hyperradial excitations. The applicability of the proposed method is demonstrated for the systems made of up to ten identical bosons with zero spin using two different two-body potentials. In particular, it has been applied to some $\alpha$-particle nuclei for which the projection of their $0^{+}$ wave functions into the “condensed state wave function” have been calculated.

Some properties of polarized neutron matter at finite temperature have been studied using the lowest order constrained variational (LOCV) method with the Argonne V18 (AV18) potential. Our results indicate that a spontaneous transition to the ferromagnetic phase does not occur. Effective mass, free energy, magnetic susceptibility, entropy, and the equation of state of polarized neutron matter at finite temperature are also calculated. A comparison is also made between our results and those of other many-body techniques.

To determine the half-life of ${}^{130}\mathrm{Te}$ we have analyzed multiple aliquots of geological telluride samples 100 times smaller than those previously reported using a unique resonance ionization mass spectrometer. We employ a low-fluence neutron irradiation that allows determination of parent and daughter from the same xenon isotopic analysis. Step heating of these irradiated samples allows the ${}^{130}\mathrm{Xe}$/${}^{132}\mathrm{Xe}$ ratio of fluids trapped inside the tellurides to be determined. Considering only samples where the trapped ${}^{130}\mathrm{Xe}$/${}^{132}\mathrm{Xe}$ ratio is demonstrably consistent with atmospheric xenon, we can avoid over- or under-estimating the half-life due to redistribution or inheritance of radiogenic ${}^{130}\mathrm{Xe}$. Combining our work with literature data, it is clear that several relatively young samples have retained xenon quantitatively since formation, allowing the half-life to be determined as $(8.0\pm 1.1)\times {10}^{20}$ yr. Older samples have clearly been affected by post-formation processing. This suggests that there is little hope of monitoring solar luminosity through the geological record of ${}^{126}\mathrm{Xe}$ production by solar neutrinos, but it is possible that geologically useful chronological information can be obtained from this system.

The validity of using a pion optical potential to incorporate the effects of final state interactions on Hanbury-Brown–Twiss interferometry is investigated. We find that, if the optical potential is real, the standard formalism is modified as previously described in the literature. However, if the optical potential is complex, a new term involving pion emission from eliminated states must be included. The size of such effects in previous work by Cramer and Miller is assessed.

The one- and two-neutron removal reactions from ${}^{17}\mathrm{C}$ and ${}^{18}\mathrm{C}$ as well as the reaction cross section of ${}^{18}\mathrm{C}$ have been studied using a carbon target at $80A$ MeV. The longitudinal momentum distributions of ${}^{15,16}\mathrm{C}$ fragments from ${}^{17}\mathrm{C}$ and ${}^{16,17}\mathrm{C}$ fragments from ${}^{18}\mathrm{C}$ were measured by a direct time-of-flight method. The width of ${}^{15}\mathrm{C}$ fragments from ${}^{17}\mathrm{C}$ is fairly smaller than that from other C isotopes. The experimental data are discussed within the framework of the Glauber model.

We present various properties of nuclear and compact-star matter, comparing the predictions from two kinds of phenomenological approaches: relativistic models (with both constant and density-dependent couplings) and nonrelativistic Skyrme-type interactions. We mainly focus on the liquid-gas instabilities that occur at subsaturation densities, leading to the decomposition of the homogeneous matter into a clusterized phase. Such study is related to the description of neutron-star crust (at zero temperature) and supernova dynamics (at finite temperature).

The ${}^1\mathrm{H}(e,\hspace{0.5em}{e}^{\text{'}}{\pi }^{+})n$ cross section was measured for arange of four-momentum transfer up to $Q^2=3.91\hspace{0.5em}{\mathrm{GeV}}^2$ at values of the invariant mass $W$ above the resonance region. The $Q^2$ dependence of the longitudinal component was found to be consistent with the $Q^2$-scaling prediction for hard exclusive processes. This suggests that the QCD factorization theorem is applicable at rather low values of $Q^2$. The transverse term falls off slower than the naive $Q^{-8}$ expectation and remains appreciable even at $Q^2=3.91\hspace{0.5em}{\mathrm{GeV}}^2$.

Mass differences are an often used as signature and measure for shell closure. Using the angular-momentum projected generator coordinate method and the Skyrme interaction SLy4, we analyze the modification of mass differences due to static deformation and dynamic fluctuations around the mean-field ground state.

The masses of very neutron-deficient nuclides close to the astrophysical $\mathit{r}\hspace{0.5em}\mathit{p}$- and $\nu \hspace{0.5em}p$-process paths have been determined with the Penning trap facilities JYFLTRAP at JYFL/Jyväskylä and SHIPTRAP at GSI/Darmstadt. Isotopes from yttrium ($Z=39$) to palladium ($Z=46$) have been produced in heavy-ion fusion-evaporation reactions. In total, 21 nuclides were studied, and almost half of the mass values were experimentally determined for the first time: ${}^{88}\mathrm{Tc}$, ${}^{90-92}\mathrm{Ru}$, ${}^{92-94}\mathrm{Rh}$, and ${}^{94,95}\mathrm{Pd}$. For the ${}^{95}\mathrm{Pd}$${}^m$, ($21/2^{+}$) high-spin state, a first direct mass determination was performed. Relative mass uncertainties of typically $\delta m/m=5\times {10}^{-8}$ were obtained. The impact of the new mass values has been studied in $\nu \hspace{0.5em}p$-process nucleosynthesis calculations. The resulting reaction flow and the final abundances are compared with those obtained with the data of the Atomic Mass Evaluation 2003.

We study the deformation property of Λ hypernuclei using the relativistic mean-field (RMF) method. We find that ${}_{\Lambda }^{29}\mathrm{Si}$ and ${}_{\Lambda }^{13}\mathrm{C}$ hypernuclei have a spherical shape as a consequence of the additional Λ particle, whereas the corresponding core nuclei, ${}^{28}\mathrm{Si}$ and ${}^{12}\mathrm{C}$, are oblately deformed. Most other hypernuclei have a similar deformation parameter to the core nucleus, in accordance with the previous study with the nonrelativistic Skyrme-Hartree-Fock method. We discuss the sensitivity of our results to the choice of pairing interaction and to the parameter set of the RMF Lagrangian.

This paper examines a prevalent departure from the standard transition-state treatment of ${\Gamma }_n/{\Gamma }_f$, the relative rate of disintegration of an excited nucleus by neutron emission or fission. This departure is caused by what we believe is an erroneous treatment of shell structure corrections. According to the transition-state theory the shell correction in the excited compound nucleus cancels out identically in the ratio ${\Gamma }_n/{\Gamma }_f$, whereas in the deviant treatment it leads to an energy-dependent fission barrier that modifies the expression for the partial width ${\Gamma }_f$. Moreover, according to the transition-state theory, the partial width ${\Gamma }_n$ depends on the shell effect in the residual nucleus that emitted the neutron, whereas in the deviant treatment this dependence is ignored. We illustrate explicitly the magnitude of the errors that the deviant treatment of ${\Gamma }_n/{\Gamma }_f$ generates in typical nuclear reactions, errors that can reach orders of magnitude at low excitation energies. We take the opportunity to describe an accurate algebraic method of evaluating integrals over shell-affected level densities that appear in the transition-state theory. We also present a new derivation of Weisskopf's nucleon evaporation formula, based on the transition-state method rather than on the statistical principle of detailed balance used by Weisskopf. This unifies the theoretical treatments of fission and nucleon evaporation.

Production cross sections of medium-mass neutron-rich nuclei obtained in the fragmentation of ${}^{136}\mathrm{Xe}$ projectiles at 1 $A$ GeV have been measured with the FRagment Separator (FRS) at GSI. The measured cross sections are compared to ${}^{238}\mathrm{U}$ fission yields and model calculations to determine the optimum reaction mechanism to extend the limits of the chart of the nuclides around the r-process waiting point at $N=82$.

An updated investigation of QCD sum rules for the first two moments of ρ-meson spectral functions, both in vacuum and in-medium, is performed with emphasis on the role of the scale related to spontaneous chiral symmetry breaking in QCD. It is demonstrated that these lowest moments of vector current spectral distributions do permit an accurate sum-rule analysis with controlled input including QCD condensates of the lowest dimensions, whereas higher moments are subject to uncertainties from higher dimensional condensates. Possible connections with Brown-Rho scaling are discussed. The factorization approximation for four-quark condensates is shown not to be applicable in any of the cases studied.

The electromagnetic response in ${}^{16}\mathrm{O}$ is studied within a recently developed approach that generates iteratively a microscopic multiphonon basis well suited for reformulating and solving exactly the nuclear eigenvalue problem within spaces of large dimensions spanned by complex configurations. These multiphonon configurations are seen to modify appreciably, dramatically in some cases, the mean field response. This is shown to be increasingly affected by the center-of-mass motion as the number of phonons increases. The method for removing such a spurious motion is briefly outlined and the effects discussed.

We have measured de-excitation $\gamma$ rays in ${}^{249}\mathrm{Cm}$ populated by one-neutron stripping reactions with a ${}^{248}\mathrm{Cm}$ target and 162-MeV ${}^{16}\mathrm{O}$, 162-MeV ${}^{18}\mathrm{O}$, and 120-MeV ${}^{13}\mathrm{C}$ beams. $\gamma$ rays in ${}^{249}\mathrm{Cm}$ were identified by measuring kinetic energies of outgoing particles using Si $\Delta E\text{−}E$ detectors. It was demonstrated that high-$j$ orbitals were selectively populated in the (${}^{16}\mathrm{O}$, ${}^{15}\mathrm{O}$) reaction having a large negative $Q$ value. We have observed eight quasiparticle states above the deformed shell gap of $N=152$. The $1/2^{+}[620]$, $1/2^{-}[750]$, and $7/2^{+}[613]$ bands were extended up to $19/2^{+}$, $19/2^{-}$, and $13/2^{+}$ states, respectively. We have established the $9/2\hspace{0.5em}9/2^{+}[615]$ state at 526 keV, the $9/2\hspace{0.5em}9/2^{+}[604]$ state with a short life of $T_{1/2}\ll 2$ ps at 1030 keV, and the $11/2\hspace{0.5em}11/2^{-}[725]$ state with $T_{1/2}=19(1)$ ns at 375 keV. Furthermore, the $17/2\hspace{0.5em}{1/2}^{+}[880]$ state, having a large component of the $k_{17/2}$ spherical single-particle state, has been identified at 1505 keV. We discuss the properties of those quasiparticle states in the framework of a deformed shell model.

The decay rates of $Q\overline{Q}$ mesons ($Q\hspace{0.5em}\varepsilon \hspace{0.5em}c$, $b$) are studied in the nonrelativistic quantum chromodynamics (QCD) formalism in terms of their short-distance and long-distance coefficients. The long-distance coefficients are obtained through phenomenological potential model description of the mesons. The model parameters that reproduces the mass spectrum of the $c\overline{c}$, $b\overline{b}$, and $c\overline{b}$ mesons are employed to study the decay widths of these mesons. We extract the mass spectrum and the respective radial wave functions from the different potential models as well as from a nonrelativistic phenomenological quark-antiquark potential of the type $V(r)=-\frac{{\alpha }_c}{r}+A{r}^{\nu }$, with ν varying from 0.5 to 2. The spin hyperfine and spin-orbit interactions are employed to obtain the masses of the pseudoscalar and vector mesons. The decay constants with QCD corrections are computed in this model as well as in the case of other potential models for comparison. The digamma and dileptonic decays of $c\overline{c}$ and $b\overline{b}$ mesons are investigated using some of the known potential models without and with radiative corrections up to the lowest order. These decay width are also computed within the nonrelativistic QCD formalism up to $O(v^4)$ by making uses of the respective spectroscopic parameters of the models. Our theoretical predictions of the decays of the $c\overline{c}$ and $b\overline{b}$ mesons and the results obtained from some of the other potential schemes are compared with the experimental values. The partial widths and lifetime of the $B_c$ meson are also computed using the model parameters and are found to be in good accordance with the experimental values.

Resonance-decay spectroscopy is used to study particle-unbound excited states produced in interactions of $E/A=50$ MeV ${}^{12}\mathrm{Be}$ on polyethylene and carbon targets. The particle-unbound states are produced in a variety of reaction mechanisms, ranging from projectile fragmentation to proton pickup. New proton-decaying excited states are observed in ${}^9\mathrm{Li}$($E^{*}=14.1\pm 0.1\hspace{0.5em}\mathrm{MeV}$, $\Gamma =207\pm 49$ keV) and ${}^{10}\mathrm{Be}$($E^{*}=20.4\pm 0.1\hspace{0.5em}\mathrm{MeV}$, $\Gamma =182\pm 74$ keV). In addition a new $\alpha$-decaying state is observed in ${}^{13}\mathrm{B}$($E^{*}=13.6\pm 0.1\hspace{0.5em}\mathrm{MeV}$, $\Gamma ⩽320$ keV). Also found was a ${}^8\mathrm{Be}$ state with $E^{*}=23\hspace{0.5em}\mathrm{MeV}$, $\Gamma =616\pm 30$ keV, which decays to the $p+{}^3\mathrm{H}+\alpha$ channel. Correlation between the fragments indicates that the decay is initiated by a proton emission to the 4.63-MeV state of ${}^7\mathrm{Li}$ and the spin of the state is $J>2$. A second $T=2$ state was confirmed in ${}^{12}\mathrm{B}$ at 14.82 MeV, which decays to the $p+{}^{11}\mathrm{Be}$, ${}^3\mathrm{H}+{}^9\mathrm{Be}$, and $\alpha +{}^8\mathrm{Li}$ channels. Its width was found to be $\Gamma ⩽100$ keV and its spin is consistent with $J^{\pi }=2^{+}$.