We present a unified description of nuclear deep-inelastic scattering (DIS) over the whole region 0<x<1 of the Bjorken variable. Our approach is based on a relativistically covariant formalism which uses analytical properties of quark correlators. In the laboratory frame it naturally incorporates two mechanisms of DIS: (i) scattering from quarks and antiquarks in the target and (ii) production of quark-antiquark pairs followed by interactions with the target. We first calculate structure functions of the free nucleon and develop a model for the quark spectral functions. In this model mechanism (ii) is responsible for the sea quark content of the nucleon while mechanism (i) governs the valence part of the nucleon structure functions. We find that the coherent interaction of q¯q pairs with nucleons in the nucleus leads to shadowing at small x and discuss this effect in detail. In the large x region DIS takes place mainly on a single nucleon. There we focus on the derivation of the convolution model. We point out that the off-shell properties of the bound nucleon structure function give rise to sizable nuclear effects.

The results of a search for the 2${\mathrm{\beta }}^{+}$ and K${\mathrm{\beta }}^{+}$ decay modes of ${}_{}{}^{78}{}_{}{}^{}\mathrm{Kr}$, in a coincidence experiment using a high pressure ionization chamber of enriched ${}_{}{}^{78}{}_{}{}^{}\mathrm{Kr}$ inside an array of sodium iodine scintillators, are presented. After 4434 h of counting time, the half-life lower limits obtained are ${\mathit{T}}_{1/2}$(K${\mathrm{\beta }}^{+}$${)}_{0\nu }$≥5.1×${10}^{21}$ yr and ${\mathit{T}}_{1/2}$(2${\mathrm{\beta }}^{+}$${)}_{0\nu +2\mathrm{}\nu }$≥2.0×${10}^{21}$ yr at 68% C.L.

We have examined the effects of nuclear and nucleon structure on the parity-violating asymmetry in elastic scattering of polarized electrons from ${}_{}{}^4{}_{}{}^{}\mathrm{He}$. We find that a small T=1 component in the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ ground state will produce a less than 1% correction to the parity-violating asymmetry, while typical strangeness admixtures in the nucleon will produce a contribution which can be reliably determined in a high-precision experiment.

The ${}_{}{}^{67}{}_{}{}^{}\mathrm{Se}$ and ${}_{}{}^{68}{}_{}{}^{}\mathrm{Se}$ isotopes near the proton drip line were produced by spallation of zirconium with 600 MeV protons at CERN. Beta decay properties were determined for the first time using the selectivity of molecular ion beams at the on-line mass separator ISOLDE. Chemically selective production was obtained through separation of the molecular ion ${\mathrm{COSe}}^{+}$. The half-lives of ${}_{}{}^{67}{}_{}{}^{}\mathrm{Se}$ and ${}_{}{}^{68}{}_{}{}^{}\mathrm{Se}$ were measured as 107±35 ms and 35.5±0.7 s respectively. From β-γ and γ-γ coincidences, and conversion-electron measurements, a decay scheme was obtained for ${}_{}{}^{68}{}_{}{}^{}\mathrm{Se}$. For the ${}_{}{}^{68}{}_{}{}^{}\mathrm{As}$ ground state and several excited states, spin and parity are unambiguously determined from β-decay rates and electromagnetic multipolarity assignments. In addition to the strong Fermi branch between the mirror ground states of ${}_{}{}^{67}{}_{}{}^{}\mathrm{Se}$ and ${}_{}{}^{67}{}_{}{}^{}\mathrm{As}$ [${\mathit{J}}^{\mathrm{\pi }}$=(5/2${)}^{\mathrm{-}}$,${\mathit{T}}_{\mathit{z}}$=±1/2], a GT branch to an excited state in ${}_{}{}^{67}{}_{}{}^{}\mathrm{As}$ is observed. Implications of ${}_{}{}^{67}{}_{}{}^{}\mathrm{Se}$ and ${}_{}{}^{68}{}_{}{}^{}\mathrm{Se}$ properties in the rp-process path are considered.

The excitation energies of the proton unbound states in ${}_{}{}^{32}{}_{}{}^{}\mathrm{Cl}$ have been measured in the ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${(}^3$He,t${)}^{32}$Cl charge exchange reaction with high accuracy. The partial widths of the unbound levels have been calculated to derive the resonance strengths of these states in the ${}_{}{}^{31}{}_{}{}^{}\mathrm{S}$(p,γ${)}^{32}$Cl reaction channel. The reaction rate for the ${}_{}{}^{31}{}_{}{}^{}\mathrm{S}$(p,γ${)}^{32}$Cl reaction has been calculated and is compared with previous estimates. The role of this reaction for the closure of the SiP cycle is discussed in terms of the temperature and density conditions in hot stellar hydrogen burning.

The shape of the low-energy part of the β-delayed α-particle spectrum of ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$ is very sensitive to the α${+}^{12}$C reduced width of the 7.117 MeV subthreshold state of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. This state, in turn, dominates the low-energy p-wave capture amplitude of the astrophysically important ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(α,γ${)}^{16}$O reaction. The α spectrum following the decay of ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$ has been measured by producing a low-energy ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}_{}^{14}{}_{}{}^{}$${\mathrm{N}}^{+}$ beam with the TRIUMF isotope separator TISOL, stopping the molecular ions in a foil, and counting the α particles and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ recoil nuclei in coincidence, in thin surface-barrier detectors. In addition to obtaining the α spectrum, this procedure determines the complete detector response including the low-energy tail. The spectrum, which contains more than ${10}^6$ events, has been fitted by R- and K-matrix parametrizations which include the measured ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(α,γ${)}^{16}$O cross section and the measured α${+}^{12}$C elastic scattering phase shifts. The model space appropriate for these parametrizations has been investigated. For ${\mathit{S}}_{\mathit{E}1}$(300), the E1 part of the astrophysical S factor for the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(α,γ${)}^{16}$O reaction at ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=300 keV, values of 79±21 and 82±26 keV b have been derived from the R- and K-matrix fits, respectively.

Measurements were performed using pion double charge exchange to observe the double isobaric analog state (DIAS) in the odd-A nuclei ${}_{}{}^{54}{}_{}{}^{}\mathrm{V}$, ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$, ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}$, and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$. These results are combined with data for other odd-A targets and used to investigate the N, Z, and A dependence of DIAS cross sections.

The technique of recoil distance method (RDM) has been utilized to determine the lifetimes in the range of 2–200 ps of the states of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Mo}$ and ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}$. The observed transition probabilities are compared with the single particle estimates (Weisskopf estimates).

Two weakly populated rotational bands with energy spacings characteristic of superdeformation (SD) have been found in the ${}_{}{}^{186}{}_{}{}^{}\mathrm{W}$${(}^{18}$O,xn) reaction at a beam energy of E=113 MeV. One of the bands corresponds to the known sequence in ${}_{}{}^{196}{}_{}{}^{}\mathrm{Pb}$, the other to an extremely weak cascade previously assigned to ${}_{}{}^{198}{}_{}{}^{}\mathrm{Pb}$. Both bands have been extended to higher frequency. The behavior of the dynamic moments of inertia for the known SD bands in the Pb nuclei are discussed. Deformation and pairing self-consistent cranked Woods-Saxon calculations of the ${\mathit{scrI}}^{\mathrm{}\left(2\right)\mathrm{}}$ moments of inertia for Z=80 gap resulting in a slightly larger quadrupole deformation of the Pb nuclei as compared to the Hg nuclei. Thus, there seems to be a slight cancellation between increased deformation and reduced alignment, both effects being rather subtle. In very recent calculations by Satul/a and Wyss [35], it is shown that the low frequency discrepancy in ${\mathit{scrI}}^{\mathrm{}\left(2\right)\mathrm{}}$ is removed, when quadrupole pairing calculations are taken into account, the main effect originating from the ${\mathit{Y}}_{21}$ component of the quadrupole pairing interaction.

The ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$(α,α’) reaction has been studied at ${\mathit{E}}_{\mathrm{\alpha }}$=40 MeV. The angular distribution of the continuum region near the ${}_{}{}^6{}_{}{}^{}\mathrm{\alpha }$+d breakup threshold (1.475 MeV) was measured for ${\mathrm{\theta }}_{\mathrm{lab}}$=${10}^{\mathrm{°}}$–${32}^{\mathrm{°}}$. The data exhibit a lowering in cross section at the forward angle region where the quasifree breakup model calculations fail to explain the data. From the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$(α,α’) data at ${\mathit{E}}_{\mathrm{\alpha }}$=50 MeV and the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$(p,p’) data at ${\mathit{E}}_{\mathit{p}}$=65 and 80 MeV we found that the breakup cross section drops below a critical momentum transfer (∼117 MeV/c). The 40 MeV data reaffirm our earlier finding. The above critical value of the momentum transfer seems to play a crucial role both in the target and projectile breakup reactions and might be useful in determining the onset of the Coulomb dissociation.

From an analysis of heavy-ion elastic scattering and fusion data available for three systems, Udagawa et al. presented evidence that the ‘‘threshold barrier’’ (T) determined from fusion is approximately equal to the ‘‘threshold energy’’ (${\mathit{E}}_{\mathit{a}}$) extracted from the imaginary part of optical potential for elastic scattering in the vicinity of the Coulomb barrier. We have extended this investigation to include seven more systems for which the relevant data are available. Furthermore, from a comparison of sets of ΔV, the polarization potential (deduced from elastic scattering), and B-T, the barrier difference (deduced from fusion) values, it is suggested that the two quantities are correlated.

The van der Waals force induced by color-dependent confining potentials in nonrelativistic quark models of the NN interaction is investigated through a full resonating group calculation where the NN channel is coupled to a channel of two orbitally polarized color octets. While exchange terms can be neglected at low energies, they prove to be essential at higher energies, where the short and intermediate ranges of the induced interaction are probed. The extent to which the latter can be simulated by effective local potentials is examined. Finally, the van der Waals force induced by a strong enough confining potential is shown to give rise to unphysical bound states.

By investigating the electromagnetic (EM) chiral series for the pseudoscalar mesons at next-to-leading order, it is shown that the ${\mathrm{\pi }}^0$ EM self-energy is O(${\mathrm{\alpha }}_{\mathrm{EM}}$${\mathit{m}}_{\mathit{u},}$d), and hence small. This observation completes the crucial step in an earlier argument, which employed previously the vanishing of the ${\mathrm{\pi }}^0$ EM self-energy in the chiral limit, and which demonstrates that the effects of not only one-photon-exchange- but also one-photon-loop graphs must be included in order to incorporate the effects of electromagnetism in hadronic systems.

The single particle energies in ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ were studied within the framework of the folded diagram many-body perturbation theory up to third order in the G matrix starting from the Bonn-A N-N interaction. The convergence of the expansion was also studied; a fast converging result was found when the self-energy insertions were summed up to infinite order. The agreement with the experimental values is reasonable.

We present a comparison of a recent fully quantal relativistic Hartree-Fock approach with its semiclassical expansion. One obtains the same trends, i.e., a slight overbinding and smaller radii, as in similar comparisons of (i) the nonrelativistic extended Thomas-Fermi method using Skyrme forces with the corresponding Hartree-Fock calculations and (ii) the relativistic semiclassical description with the relativistic Hartree theory.

${\mathit{Q}}^2$ variation of the nuclear-structure-function ratio ${\mathit{F}}_2^{\mathit{A}}$(x,${\mathit{Q}}^2$)/${\mathit{F}}_2^{\mathit{D}}$(x,${\mathit{Q}}^2$) is investigated in a parton model with ${\mathit{Q}}^2$-rescaling and parton-recombination effects. Calculated results are compared with the New Muon Collaboration (NMC) and the Fermilab-E665 experimental data. We find that our theoretical results show small ${\mathit{Q}}^2$ variations and that they are consistent with the data within present experimental accuracy.

Recently, a paper by Meek et al. [Phys. Rev. C 41, 2921 (1990)] purported to show that a new technique for measuring atomic masses had been developed sufficiently to demonstrate an error in the accepted value for the mass of ${}_{}{}^{134}{}_{}{}^{}\mathrm{Xe}$. However, new measurements of the masses of several stable isotopes of Xe, which are in agreement with other data, indicate that this claim may be premature.

The differences between the deformed-potential and folding-model descriptions of inelastic nuclear scattering, attention to which has been called recently by Beene, Horen, and Satchler [Phys. Rev. C 48, 3128 (1993)], were pointed out already some time ago by contrasting the rules of equal deformation lengths and equal normalized multipole moments for the optical potential and the underlying nucleon distribution of the excited nucleus.