Analyzing power measurements for both inclusive $\left(\overrightarrow{p}{,p}^{\prime }\right)$ and exclusive $(\overrightarrow{p},2p)$ and $(\overrightarrow{p},np)$ quasifree scattering at 200 MeV from ${}^2\mathrm{H}$ and ${}^{12}\mathrm{C}$ have been completed in the angular range from 27° to 34°. Previous experimental and theoretical work has indicated non-negligible suppression of the inclusive $\left(\overrightarrow{p}{,p}^{\prime }\right)$ analyzing powers with respect to impulse approximation calculations. Conversely, both suppression and enhancement of the isovector $(\overrightarrow{p},n)$ analyzing power data have been found depending on the mass number of the target. Both nonrelativistic and fully relativistic calculations have sought to explain these features. However to address such questions within the inclusive data, it is important to fully understand the makeup of the inclusive spectra. This ensures that any “nonconventional” aspects of the data do not arise from contamination of the quasifree scattering yield.

The reaction $\mathrm{pp}\Rightarrow p{\pi }^{+}X$ was studied in order to look for dibaryons at invariant masses $M_{\mathrm{pX}}.$ The experiment was performed at three different energies ${(T}_p=1520\mathrm{}$, 1805, and 2100 MeV) and at several different angles from $0°$ up to $17°$ (lab). Narrow dibaryons were observed in invariant mass spectra at 2050, 2122, and 2150 MeV. The corresponding numbers of standard deviations vary between 3.2 and 12.6. The mass of these narrow dibaryons agree with systematic studies of dibaryonic masses experimentally observed through many experiments performed by various collaborations. Such a systematic study allows us to define the mean dibaryonic mass spectrum, and is found to be in agreement with the spectrum calculated within a simple phenomenological mass formula based on color magnetic interactions between two colored quark clusters.

A relativistic model is developed for the description of the process $p+d{\leftrightarrow }^3\mathrm{He}+{\gamma }^{*}.$ It is based on the impulse approximation, but is explicitly gauge invariant and Lorentz covariant. The model is applied to radiative proton-deuteron capture and electrodisintegration of ${}^3\mathrm{He}$ at intermediate energies. Results for cross sections and vector and tensor analyzing powers are presented.

We use equations for Faddeev amplitudes to solve the shell-model problem for four nucleons in a model space that includes up to $14ħ\Omega$ harmonic-oscillator excitations above the unperturbed ground state. Two- and three-body effective interactions derived from the Reid93 and Argonne V8’ nucleon-nucleon potentials are used in the calculations. Binding energies, excitation energies, point-nucleon radii, and electromagnetic and strangeness charge form factors for ${}^4\mathrm{He}$ are studied. The structure of the Faddeev-like equations is discussed and a formula for the matrix elements of the permutation operators in a harmonic-oscillator basis is given. The dependence on harmonic-oscillator excitations allowed in the model space and on the harmonic-oscillator frequency is investigated. It is demonstrated that the use of three-body effective interactions improves the convergence of the results.

It is shown that the ten Hermitian generators of the Poincaré group derived from standard Hermitian Lagrangians which describe interacting fields can be block diagonalized by one and the same unitary transformation such that the space of a fixed number of nucleons is separated from the rest of the space. The existence proof is carried through using a formal power series expansion in the coupling constant to all orders. In this manner one arrives at effective Hermitian generators of the Poincaré group which act in the two subspaces separately.

Systematic nuclear resonance fluorescence experiments including model-independent parity determinations provided clear evidence for strong, isolated $E1\mathrm{}$ excitations at excitation energies of 3.3–3.5 MeV in the spherical, semimagic nuclei ${}^{116,118,120,122,124}\mathrm{Sn}.$ The corresponding $J^{\pi }{=1\mathrm{}}^{-}$ states are interpreted as two-phonon excitations ${(2\mathrm{}}^{+}\otimes 3^{-}).\mathrm{}$ The excitation energies $E_x{(1\mathrm{}}^{-})$ and reduced excitation probabilities $B\left(E1\mathrm{}\right)\mathrm{}\uparrow$ are nearly constant in the entire isotopic chain $A=116\mathrm{}–124.$ The results are described in the framework of quasiparticle-phonon-model calculations.

The level-mixing resonance technique applied to $\beta$-decaying nuclei $(\beta$-LMR) is a well-established tool for measuring the ground state quadrupole moments of nuclei away from stability. These experiments yield the quadrupole to magnetic moment ratio, provided the electric field gradient (EFG) of the implanted nuclei in the crystal is known. By combining $\beta$-LMR with $\beta$ nuclear magnetic resonance $(\beta$-NMR), both the quadrupole moment Q and the magnetic moment $\mu$ can be simultaneously extracted in a single experiment. A major advantage of this technique is that the initial nuclei need only to be aligned, and not necessarily polarized. Alignment is generally easier to produce than polarization, and occurs at the highest yield point in the nuclear reaction mechanism. This is an especially important consideration in the study of dipole and quadrupole moments of nuclei in the region of the drip lines. We report here the successful application of this combined technique to the known case of ${}^{12}\mathrm{B}\left(\mathrm{Mg}\right).\mathrm{}$ The main features of the LMR-NMR technique are described.

Magnetic dipole moments of excited states in ${}^{84}\mathrm{Zr}$ and the $N=46\mathrm{}$ isotones ${}^{86}\mathrm{Zr}$ and ${}^{87}$Nb were measured. The recoil distance transient field method, which is a coincidence technique combining the recoil distance and the transient field methods, was applied. The measurement was performed such that it was sensitive only to those excited states which were populated a few picoseconds after the nuclear reaction. The influence of unobserved continuum feeding on the measured precession angles can thus be neglected. The results are compared with the values obtained using other experimental techniques and with shell model calculations.

Excited states of ${}^{65}\mathrm{Ga}$ and ${}^{67}\mathrm{Ga}$ nuclei were populated through the ${}^{12}\mathrm{C}{(}^{58}\mathrm{Ni},\alpha p)$ and ${}^{12}\mathrm{C}{(}^{58}\mathrm{Ni},3p)$ reactions, respectively, and investigated by in-beam $\gamma$-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and $\gamma$ rays. The level schemes of ${}^{65,67}\mathrm{Ga}$ were constructed on the basis of $\gamma \gamma$-coincidence relations up to 8.6 and 10 MeV excitation energy, and $I^{\pi }=27/2\mathrm{}$ and ${33/2}^{+}$ spin and parity, respectively. The structure of ${}^{65,67}\mathrm{Ga}$ nuclei was described in the interacting boson-fermion plus broken pair model, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in the boson-fermion basis states. Most of the states were assigned to quasiparticle + phonon and three quasiparticle configurations on the basis of their electromagnetic decay properties.

The lifetimes of excited states in ${}^{115}\mathrm{Sn}$ have been measured using the Doppler shift attenuation method in the reaction ${}^{113}\mathrm{Cd}(\alpha ,2n\gamma )$ at $E_{\alpha }=27.2\mathrm{}\hspace{0.5em}\mathrm{MeV}$. Lifetimes were obtained for 18 states and lifetime limits for 6 states with $E_x<~4\hspace{0.5em}\mathrm{MeV}$ and $J<~23/2$. The experimentally obtained $B\left(\sigma L\right)$ values for transitions deexciting positive-parity states are compared with calculations in the framework of the Bardeen-Cooper-Schrieffer quasiparticle model and the interacting boson fermion model, whereas the values for transitions between negative-parity states are discussed qualitatively within a core-particle coupling picture. The value of $B\left(E2\mathrm{}\right)=3.5\mathrm{}\left(11\right)\mathrm{}$ Weisskopf units (W.u.) for the transition linking the ${19/2}^{-}$ state of the intruder $\nu h_{11/2}\pi 2p2h$ band to the ${15/2}^{-}$ state of the $\nu h_{11/2}\otimes 2_1^{+}$ multiplet strongly supports the configuration $\nu h_{11/2}\pi {(g}_{9/2}^{-2}{g}_{7/2}^2)$ ascribed to this band.

High-spin states have been populated in ${}_{53}^{117}\mathrm{I}$ via the ${}^{90}\mathrm{Zr}{(}^{31}\mathrm{P},2p2n)$ reaction at 150 MeV, using the EUROGAM II $\gamma$-ray spectrometer to record high-fold $\gamma$-ray coincidences. A quadruples $\gamma$-ray analysis $\left({\gamma }^4\right)$ has been used to extend the known level scheme. In addition to several aligned noncollective states, a new high-spin band showing characteristics of smooth termination has been established at and linked into the low-spin level scheme. Its structure has been inferred through comparison with cranked Nilsson-Strutinsky calculations.

Lifetimes of states in ${}^{74}\mathrm{Br}$ produced by the ${}^{60}\mathrm{Ni}{(}^{16}\mathrm{O},np)$ reaction at 50 MeV have been measured by using the recoil-distance method. From these experiments several reduced transition strengths for the low energy states have also been determined. The results show that the alternating pattern in the $B\left(M1\mathrm{}\right)\mathrm{}$ strengths of the yrast positive parity band is preserved across the signature inversion region.

The β-decay properties of ${}^{67}\mathrm{Co}$ produced in proton-induced fission of ${}^{238}\mathrm{U}$ were measured by the detection of β-delayed γ rays emitted from an isotopically pure mass-separated source obtained by laser ionization. The measured half-life of 0.425(20) s is more accurate than previous values. New γ transitions were observed, and corresponding branching ratios and $\log \mathrm{ft}$ values were deduced. The ${}^{67}\mathrm{Co}$ decay scheme is discussed in terms of the single-particle shell model.

High-spin states were studied in ${}^{181,183}\mathrm{Au}$ and resulted in the identification of several new prolate rotational bands based on $\pi i_{13/2},$ $\pi h_{9/2},$ $\pi f_{7/2},$ and $\pi h_{11/2}$ configurations. The alignment and moment of inertia features of the intruder bands are compared with ground-state bands in Pt nuclei. From these features, it can be concluded that a strongly interacting $(\pi h_{9/2}{)}^2$ alignment is occurring in the $\pi i_{13/2}$ bands in Au and the ground-state bands in Pt. In addition, bandhead energies and deformation parameters are calculated for deformed configurations in the framework of a microscopic-macroscopic shell-correction model. These calculations are compared with experimental values in Re and Ir, as well as, Au isotopes. Interaction properties between known $\pi h_{9/2}$ and $\pi f_{7/2}$ rotational bands are also discussed and compared with results from a cranked-shell model. Experimental $B\left(M1\mathrm{}\right)/B\left(E2\mathrm{}\right)\mathrm{}$ ratios between these bands are compared with results from a particle-rotor calculation.

Binding energies and other global properties of nuclei in the middle of the $\mathrm{pf}$ shell, such as $M1,E2,$ and Gamow-Teller sum rules, have been obtained using a new shell model code (NATHAN) written in quasispin formalism and using a $j-j$-coupled basis. An extensive comparison is made with the recently available shell model Monte Carlo results using the effective interaction KB3. The binding energies for nearly all the ${1f}_{7/2}$ nuclei are compared with the measured (and extrapolated) results.

In the framework of the random phase approximation in the continuum we calculate the strength function of the $4ħ\omega$ isoscalar monopole giant resonance in ${}^{208}\mathrm{Pb}$. The one-particle continuum plays an important role in the formation of the structure of the strength function. Most interesting is the appearance of some narrow resonances at large excitation energy. We discuss the results obtained from the point of view of resonance trapping which is known to appear due to the strong coupling of the resonance states via the continuum.

We have investigated the ${}^{18}\mathrm{C}$ longitudinal momentum distributions from fragmentation of ${}^{19}\mathrm{C}$, calculated in a binary coupling model. We have found that inclusion of a low-lying resonance in the ${}^{19}\mathrm{C}$, with $E_{\mathrm{res}}\sim 0.2\hspace{0.5em}\mathrm{MeV}$, and sequential decay of this state together with the one-neutron stripping process, can simultaneously describe the different fragmentation data measured at intermediate and high projectile energies.

We consider pairing in a dilute system of fermions with a short-range interaction. While the theory is ill-defined for a contact interaction, the BCS equations can be solved in the leading order of low-energy effective field theory. The integrals are evaluated with the dimensional regularization technique, giving analytic formulas relating the pairing gap, the density, and the energy density to the two-particle scattering length.

Single- and double-$\beta$ decay transitions of Fermi type are discussed within a schematic model. The amplitudes associated with these transitions as well as some basic properties of the model like ground state and excitation energies are reproduced quite well in terms of a multistep variational procedure. The procedure, fully developed in a boson space, searches for the best ground state wave function through a series of minimizations. Excited states are constructed in terms of a phonon operator acting on the ground state so derived and their structure is also determined via a variational mechanism. Results obtained within the quasiparticle random phase approximation (QRPA) are shown for reference and also the comparison with other approaches like the renormalized QRPA is discussed. A considerable improvement is obtained within the present approach.

We formulate a theory for the transfer of energy from collective degrees of freedom to internal degrees of freedom when the former belong to the adiabatic large-amplitude regime. The framework is that of an extended mean-field theory including dissipation, with the following salient features: (i) The Born-Oppenheimer approximation is extended to finite excitation energy by the introduction of the concept of thermal state, that is pure with respect to collective coordinates and a (square root of $a)$ density matrix with respect to internal coordinates. (ii) By assuming that these states form an approximate complete set for application of the Kerman-Klein method, the self-consistent theory of large amplitude collective motion is extended to finite excitation energy. (iii) The mean-field limit is taken, and further study is carried out in the basis of natural orbitals that diagonalizes the one-particle density matrix. In the approximation maintained uniformly in this work, the equations of motion for the orbitals are shown to be of Hamiltonian form; to these are conjoined the master equations for the time rate of change of the occupation numbers. The latter are studied in two extreme limits. In the collisionless limit, dissipation still arises from the response of the mean field to the collective motion (one-body friction). At the opposite extreme, collisions are assumed to be so effective as to force the system always to be in a state of local (constrained) equilibrium. (iv) We review a procedure by which the noncollective variables in the Hamiltonian may be eliminated, leading to equations of motion for the collective variables with dissipative terms that in general depend on the history of the system. The limit of instantaneous friction can be justified in an adiabatic approximation. (v) A decoupling procedure is developed for deriving the form of these equations of motion from the mean-field theory, with the ultimate aim of obtaining the macroscopic parameters that appear in the classical equations of motion for the collective variables. This procedure generalizes that developed in extensive previous work on large amplitude collective motion at zero temperature. (vi) Associating the dissipative equations of motion for the collective variables with one of the assumptions concerning the rates of change of the occupation numbers provides a description of the relaxation of a system initially perturbed from a state of dynamic equilibrium.