The inclusion of the continuum in the study of weakly bound three-body systems is discussed. A transformed harmonic oscillator basis is introduced to provide an appropriate discrete and finite basis for treating the continuum part of the spectrum. As examples of the application of the method the strength functions corresponding to several operators that couple the ground state to the continuum are investigated, for ${}^6\mathrm{He}$, and compared with previous calculations. It is found that the energy moments of these distributions are accurately reproduced with a small basis set.

In a model that treats $T=3/2$ states in $A=15$ as combinations of one-particle, two-hole and three-particle, four-hole, states, we have computed Coulomb energies and hence are able to predict energies in ${}^{15}\mathrm{N}$, ${}^{15}\mathrm{O}$, and ${}^{15}\mathrm{F}$, given the energies in ${}^{15}\mathrm{C}$. Among our findings is that the first two levels of ${}^{15}\mathrm{F}$ are reasonable well described in this (0 + 2)$\hslash \omega$ space, using only the three lowest configurations for each state.

The nonmesonic weak decay of a Λ hyperon is studied in nuclear matter. Special emphasis is placed on a consistent treatment of correlations introduced by the strong interaction on its weak counterpart. The latter is described by the exchange of mesons between the initial $\Lambda N$ state and the final NN one. The weak decay is studied in terms of the weak self-energy, which allows a systematic evaluation of short-range and tensor correlation effects that are determined by a realistic hyperon-nucleon interaction. The admixture of $\Sigma N$ components through the strong interaction is also included in the calculation of the Λ decay properties. Calculations for the ratio of the neutron-induced partial width to the corresponding proton-induced one, ${\Gamma }_n/{\Gamma }_p$, are discussed in connection with recent experimental results.

When the $N=Z$ line approaches the proton dripline above ${}^{56}\mathrm{Ni}$ an increasing distortion of mirror symmetry is expected as the proton-rich partner becomes marginally bound. Urkedal and Hamamoto have considered ${}^{71}\mathrm{Kr}$ and suggest the distortion could lead to a different ground-state spin to its mirror partner ${}^{71}\mathrm{Br}$, based on the reinterpretation of a β-decay measurement. This would be a unique situation in $T=1/2$ nuclei. We have performed a new in-beam spectroscopic measurement of ${}^{71}\mathrm{Br}$, following the ${}^{40}\mathrm{Ca}$(${}^{40}\mathrm{Ca}$,2αp) reaction at 160 MeV and using Gammasphere. Many new states have been found, with candidates for eight Nilsson bandheads below 1 MeV. Cross-linking decays tightly constrain most of the angular momentum assignments. The ${}^{71}\mathrm{Kr}$ β-decay data, seen in the light of this new information on ${}^{71}\mathrm{Br}$, support the original ground-state assignment of ${}^{71}\mathrm{Kr}$ as $J^{\pi }=5/2^{-}$, as would be normally expected for the mirror partner of $J^{\pi }=5/2^{-}$ ${}^{71}\mathrm{Br}$.

Charm elliptic flow in heavy-ion collisions at the Relativistic Heavy Ion Collider is studied in a multiphase transport model. Assuming that the cross section for charm quark scattering with other light quarks is the same as that between light quarks, we find that both charm and light quark elliptic flows are sensitive to the value of the cross section. Compared to that of light quarks, the elliptic flow of charm quarks is smaller at low transverse momentum but approaches comparable values at high transverse momentum. Similar features are seen in the elliptic flow of charmed mesons as well as that of the electrons from their semileptonic decays when the charmed mesons are produced from quark coalescence during hadronization of the partonic matter. To describe the large electron elliptic flow observed in available experimental data requires a charm quark-scattering cross section that is much larger than that given by the perturbative quantum chromodynamics.

We present our results on multiplicity fluctuations in the framework of the string clustering approach. We compare our results—with and without clustering formation—with CERN Super Proton Synchrotron NA49 data. We find a nonmonotonic behavior of these fluctuations as a function of the collision centrality, which has the same origin as the observed fluctuations of transverse momentum: the correlations between the produced particles because of the cluster formation.

Correlation between shower partons is first studied in high-$p_T$ jets. Then within the framework of parton recombination the correlation between pions in heavy-ion collisions is investigated. Since thermal partons play very different roles in central and peripheral collisions, it is found that the correlation functions of the produced hadrons behave very differently at different centralities, especially at intermediate $p_T$. The correlation function that can best exhibit the distinctive features is suggested. There is not a great deal of overlap between what we can calculate and what has been measured. Nevertheless, some aspects of our results compare favorably with experimental data.

Phase diagram of strongly interacting matter is discussed within the exactly solvable statistical model of the quark-gluon bags. The model predicts two phases of matter: the hadron gas at a low temperature T and baryonic chemical potential ${\mu }_B$, and the quark-gluon gas at a high T and/or ${\mu }_B$. The nature of the phase transition depends on a form of the bag mass-volume spectrum (its preexponential factor), which is expected to change with the ${\mu }_B/T$ ratio. It is therefore likely that the line of the first-order transition at a high ${\mu }_B/T$ ratio is followed by the line of the second-order phase transition at an intermediate ${\mu }_B/T$, and then by the lines of higher-order transitions at a low ${\mu }_B/T$.

A coupled-channels analysis, based on the $K$-matrix approach, is presented for photo-induced kaon production. It is shown that channel coupling effects are large and should not be ignored. The importance of contact terms in the analysis, associated with short-range correlations, is pointed out. The extracted parameters are compared with $\mathrm{SU}(3)$ model predictions.

We investigate the structure of the SU(3) octet and decuplet baryons employing a constituent quark model designed for the study of the baryon-baryon interaction and successfully applied to the meson spectra. The model considers through the interacting potential perturbative, one-gluon exchange, and nonperturbative, boson exchanges and confinement, aspects of the underlying theory, quantum chromodynamics (QCD). We solve the three-quark problem by means of the Faddeev method in momentum space. We analyze the effect of the different terms in the interaction and make contact with the use of relativistic kinematics. We find an explanation to the strong contribution of the pseudoscalar forces in the semirelativistic approach for the octet baryons. A phenomenological recipe for the regularization parameter of the one-gluon exchange is found.

The $\pi \pi$ scattering amplitude in the σ-channel is studied at finite baryonic density in the framework of a chiral unitary approach which successfully reproduces the meson meson phase shifts and generates the $f_0$ and σ resonances in vacuum. We address here a new variety of mechanisms recently suggested to modify the $\pi \pi$ interaction in the medium, as well as the role of the s–wave selfenergy, in addition to the p–wave, in the dressing of the pion propagators.

A widely used relativistic Fermi gas model and plane-wave impulse approximation approach are tested against electron-nucleus scattering data. Inclusive quasielastic cross sections are calculated and compared with high-precision data for ${}^{12}\mathrm{C}$, ${}^{16}\mathrm{O}$, and ${}^{40}\mathrm{Ca}$. A dependence of agreement between the calculated cross sections and the data on momentum transfer is shown. Results for the ${}^{12}\mathrm{C}$(${\nu }_{\mu },{\mu }^{-}$) reaction are presented and compared with experimental data of the LSND Collaboration.

While cosmic ray muons themselves are relatively easy to veto in underground detectors, their interactions with nuclei create more insidious backgrounds via (i) the decays of long-lived isotopes produced by muon-induced spallation reactions inside the detector, (ii) spallation reactions initiated by fast muon-induced neutrons entering from outside the detector, and (iii) nuclear recoils initiated by fast muon-induced neutrons entering from outside the detector. These backgrounds, which are difficult to veto or shield against; are very important for solar, reactor, dark matter, and other underground experiments, especially as increased sensitivity is pursued. We used FLUKA to calculate the production rates and spectra of all prominent secondaries produced by cosmic ray muons, in particular focusing on secondary neutrons, because of their importance. Since the neutron spectrum is steeply falling, the total neutron production rate is sensitive to just the relatively soft neutrons and not the fast-neutron component. We show that the neutron spectrum in the range ∼10–100 MeV can instead be probed by the $(n,p)$-induced isotope production rates ${}^{12}\mathrm{C}$$(n,p)$${}^{12}\mathrm{B}$ and ${}^{16}\mathrm{O}$$(n,p)$${}^{16}\mathrm{N}$ in oil- and water-based detectors. The result for ${}^{12}\mathrm{B}$ is in good agreement with the recent KamLAND measurement. Besides testing the calculation of muon secondaries, these results are also of practical importance, since ${}^{12}\mathrm{B}$ ($T_{1/2}=20.2$ ms, $Q=13.4\text{MeV}$) and ${}^{16}\mathrm{N}$ ($T_{1/2}=7.13$ s, $Q=10.4\text{MeV}$) are among the dominant spallation backgrounds in these detectors.

Cross sections of the ${}^{186}\mathrm{W}$, ${}^{187}\mathrm{Re}$, ${}^{188}\mathrm{Os}$($\gamma ,n$) reactions were measured using quasimonochromatic photon beams from laser Compton scattering with average energies from 7.3 to 10.9 MeV. The results are compared with the predictions of Hauser-Feshbach statistical calculations using four different sets of input parameters. In addition, the inverse neutron capture cross sections were evaluated by constraining the model parameters, especially the $E1$ strength function, on the basis of the experimental data. The present experiment helps to further constrain the correction factor $F_{\sigma }$ for the neutron capture on the 9.75 keV state in ${}^{187}\mathrm{Os}$. Implications of $F_{\sigma }$ for the Re-Os cosmochronology are discussed with a focus on the uncertainty in the estimate of the age of the galaxy.

We study the bulk viscosity of strange quark matter in a quasiparticle model at finite chemical potential by extrapolating the previous quasiparticle model of finite temperature lattice quantum chromodynamics. The more proper bulk viscosity coefficient can be given in this model where chemical potential μ and coupling constant $g$ are interdependent. We also apply our result to determine the critical rotation of strange stars by r-mode instability window. Our model is compatible to the millisecond pulsar data for a wide range of mass and radius of the stars.

The determination of the $0^{°}-{180}^{°}$ asymmetry ($A_{\gamma }$), which arises because of the parity nonconserving matrix element, in the 751-keV γ decay of polarized $17/2^{-}$ isomers in ${}^{93}\mathrm{Tc}$ with respect to the direction of polarization is reported. A combined analysis of the present results together with those from our earlier work yields an effect of two standard deviations.

High-spin states of ${}^{152}\mathrm{Gd}$ have been studied via the ${}^{148}\mathrm{Nd}$(${}^9\mathrm{Be}$,$5n){}^{152}\mathrm{Gd}$ fusion-evaporation reaction at a beam energy of 54 MeV. The ground-state band, octupole band, and $\beta$ band have been extended up to spins ${20}^{+}$, ${21}^{-}$, and ${16}^{+}$, respectively. A possible aligned two quasineutron band, which becomes the yrast band above the spin ${16}^{+}$, was observed for the first time. The kinematic behaviors of the ground-state bands and yrast bands in ${}^{152,154}\mathrm{Gd}$ indicate that the shape of ${}^{152}\mathrm{Gd}$ may change with increasing rotational frequency and the difference of quadrupole deformations between ${}^{152}\mathrm{Gd}$ and ${}^{154}\mathrm{Gd}$ obviously reduces around the first band crossing region. These observations are consistent with the theoretical calculations using cranked Woods-Saxon-Strutinsky methods. The first band crossing observed in ${}^{152}\mathrm{Gd}$ can be ascribed to the alignment of a pair of $i_{13/2}$ neutrons. The identical ground-state bands in ${}^{152}\mathrm{Gd}$ and ${}^{154}\mathrm{Dy}$ were extended.

The lifetimes of excited states belonging to the lowest lying positive-parity bands in ${}^{106,108}\mathrm{Cd}$ have been measured using the Doppler-shift attenuation method. The resulting B(E2) transition rates show a significant decrease with increasing spin in ${}^{106}\mathrm{Cd}$, whereas in ${}^{108}\mathrm{Cd}$ there is tentative evidence for a similar effect. The results are compared with cranking and semiclassical model calculations, which indicate that the structures have the properties expected from an “antimagnetic” rotational band resulting from the coupling of $g_{9/2}$ proton holes to aligned pairs of $h_{11/2}$ and $g_{7/2}$ neutron particles.