Experimental results of the $d\overrightarrow{p}\mathrm{dp}\gamma$ reaction are presented for several observables with deuteron projectile energies between 437 MeV and 559 MeV. The kinematically complete measurements were performed at the CELSIUS storage ring with the PROMICE/WASA setup. Angular and spectral distributions of the charged ejectiles are decomposed into fractions that can be attributed to a quasifree $n\overrightarrow{p}d\gamma$ process with a spectator proton and to a process involving all three nucleons. Within the acceptance of the detector, about two thirds of the events are associated to the quasifree process; the remainder are characterized by substantial transverse momentum components transferred to a participating outgoing proton.

Lifetime measurements in the mirror nuclei ${}^{47}\mathrm{Cr}$ and ${}^{47}\mathrm{V}$ were performed by means of the Doppler-shift attenuation method using the multidetector array EUROBALL, in conjunction with the ancillary detectors ISIS and the Neutron Wall. The determined transition strengths in the yrast cascades are well described by full $\mathrm{pf}$ shell model calculations.

Fission fragment angular distributions have been measured for ${}^{19}\mathrm{F}{+}^{194,198}\mathrm{Pt}$ systems in the laboratory energy range from 88 to 104 MeV and the fission fragment angular anisotropy data have been compared with the statistical saddle-point model calculations. The anisotropy data for ${}^{19}\mathrm{F}{+}^{198}\mathrm{Pt}{(}^{217}\mathrm{Fr}$ with compound nucleus neutron number $N_c=130)$ are in good accord with the calculations over the entire range of bombarding energies except at the highest energy point. However, the data for ${}^{19}\mathrm{F}{+}^{194}\mathrm{Pt}{(}^{213}\mathrm{Fr}$ with $N_c=126)$ though consistent on the average with the calculations, show noticeable deviation at a few energies.

The recently proposed infinite square well E(5) description of nuclei at the critical point of the phase transition from vibrator to $\gamma$-soft rotor is extended to include the effects of finite well depth. The evolution of nuclear observables as a function of well depth is studied, and observables sensitive to finite well depth are identified.

The decays of the very neutron rich Sn isotopes ${}^{135–137}\mathrm{Sn}$ were studied at CERN/ISOLDE using isotopic and isobaric selectivity achieved by the use of a resonance ionization laser ion source and mass spectroscopy, respectively. Neutron decay rates, γ-ray singles, and γ-γ coincidence data were collected as a function of time. The half-life ${(T}_{1/2})$ and delayed neutron emission probability ${(P}_n)$ values of ${}^{135}\mathrm{Sn}$ were measured to be 530(20) ms and 21(3)%, respectively. For ${}^{136}\mathrm{Sn},$ a $T_{1/2}$ of 250(30) ms was determined along with a $P_n$ value of 30(5)%. For ${}^{137}\mathrm{Sn},$ a $T_{1/2}$ of 190(60) ms and a $P_n$ value of 58(15)% were deduced. Identification of low-energy transitions in ${}^{135}\mathrm{Sb}$ was made possible by comparison of laser-on and laser-off γ-ray spectra. Those data combined with γ-γ coincidence spectra were used to construct a level scheme for ${}^{135}\mathrm{Sb}$ that includes an unexpectedly low first excited state at 282 keV. A ground state β branch of 33.2% was measured by following the growth and decay of the ${}^{135}\mathrm{Sb}$ daughter. Shell-model calculations are consistent with the observed ${}^{135}\mathrm{Sb}$ level structure and can account for a lowered first excited state.

The astrophysically important reaction ${}^{14}\mathrm{O}(\alpha {,p)}^{17}\mathrm{F}$ has been studied through a measurement of the time-inverse ${p(}^{17}\mathrm{F},\alpha {)}^{14}\mathrm{O}$ reaction using a radioactive ${}^{17}\mathrm{F}$ beam. Resonance parameters for several states above an excitation energy of 7 MeV in ${}^{18}\mathrm{Ne}$ have been obtained. Through a measurement of the partial widths for elastic and inelastic proton scattering, it was determined that for these resonances the contribution of the ${}^{14}\mathrm{O}(\alpha {,p)}^{17}{\mathrm{F}}^{*}$ branch populating the first excited state in ${}^{17}\mathrm{F}$ is small. The results indicate that the contribution of resonances above $E_x=7\mathrm{}\mathrm{MeV}$ to the astrophysical $(\alpha ,p)$ reaction rate is smaller than was previously assumed.

The Brueckner-Hartree-Fock formalism is applied to study spin polarized neutron matter properties. Results of the total energy per particle as a function of the spin polarization and density are presented for two modern realistic nucleon-nucleon interactions, Nijmegen II and Reid93. We find that the dependence of the energy on the spin polarization is practically parabolic in the full range of polarizations. The magnetic susceptibility of the system is computed. Our results show no indication of a ferromagnetic transition which becomes even more difficult as the density increases.

We compare the scattering amplitude resulting from the several quasipotential equations for scalar particles. We consider the Blankenbecler-Sugar, spectator, Thompson, Erkelenz-Holinde, and equal-time equations, which were solved numerically without decomposition into partial waves. We analyze both negative-energy state components of the propagators and retardation effects. We found that the scattering solutions of the spectator and the equal-time equations are very close to the nonrelativistic solution even at high energies. The overall relativistic effect increases with the energy. The width of the band for the relative uncertainty in the real part of the scattering T matrix, due to different dynamical equations, is largest for backward-scattering angles where it can be as large as 40%.

The two neutrino double beta decay of ${}^{100}\mathrm{Mo}$ for the $0^{+}\to 0^{+}$ transition is studied in the Hartree-Fock-Bogoliubov (HFB) framework. Prior to the calculation of the double Gamow-Teller matrix element $M_{\mathrm{GT}}^{2\nu },$ the reliability of the intrinsic wave functions has been established by obtaining an overall agreement between a number of theoretically calculated spectroscopic properties and the available experimental data for ${}^{100}\mathrm{Mo}$ and ${}^{100}\mathrm{Ru}.$ It has been further noticed that there is a necessity of an appropriate amount of deformation in the HFB intrinsic state to obtain a realistic $M_{\mathrm{GT}}^{2\nu }.$

High-spin states in ${}^{154}\mathrm{Dy}$ were studied with the Gammasphere spectrometer using the ${}^{36}\mathrm{S}{(}^{122}\mathrm{Sn},4n)$ reaction. Band terminating states were identified in the spin range $I=(36\mathrm{}–48)ħ,$ and were found to compete with collective rotational cascades up to the highest observed spins. Several “sidebands” feeding the terminating structures were identified as well. A band dominated by $M1\mathrm{}$ transitions was observed to terminate at $I^{\pi }{=42\mathrm{}}^{-}.$ The data are interpreted within the framework of configuration-dependent cranked Nilsson-Strutinsky calculations without pairing.

The proton and neutron inclusive distributions in the projectile fragmentation region of $\mathrm{pA}$ collisions are studied in the valon model. Momentum degradation and flavor changes due to the nuclear medium are described at the valon level using two parameters. Particle production is treated by means of the recombination subprocess. The centrality dependences of the net proton and neutron spectra of the NA49 data are satisfactorily reproduced. The effective degradation length is determined to be 17 fm. Pion inclusive distributions can be calculated without any adjustable parameters.

A three body model for ${}^{11}\mathrm{Li}$ proposed earlier [S. Dasgupta et al., Phys. Rev. C 50, R510 (1994)] employing separable potentials for $n-n$ and $n{-}^9\mathrm{Li}$ interactions has been extended to study the recently observed excited states in ${}^{11}\mathrm{Li}$ above the three body breakup threshold. The $n{-}^9\mathrm{Li}$ potential used here includes both s- and p-state interactions so as to incorporate the virtual s-state and p-wave resonance observed experimentally. The resulting coupled integral equations for the spectator functions have been computed using the method of rotating the integral contour of the kernels in the complex plane. The model predicts the ground state energy as well as the three excited states in reasonable agreement with the data recently obtained. Dynamical content of the two body input potentials in the three body wave function has also been analyzed through the three-dimensional plots.

The β delayed deuteron decay of ${}^6\mathrm{He}$ has been measured at the TISOL facility at TRIUMF. For the β-particle measurement a silicon-germanium telescope array has been used. To separate deuterons from $\alpha$ particles and to obtain the spectral form of the deuteron decay, a $d-\alpha$ coincidence technique has been employed using two opposite silicon detectors. The β branch has been determined from the geometry of the experiment and also by comparison with the well-known $\beta -\alpha$ decay modes of ${}^{16}\mathrm{N}$ and ${}^8\mathrm{Li}.$ A branching ratio of $(1.8\mathrm{}\pm 0.9)\times {10}^{-6}$ above the $\beta$ cutoff (350-keV deuteron laboratory energy) and $(2.6\mathrm{}\pm 1.3)\times {10}^{-6}$ for the entire spectrum has been determined for this decay. In the course of the measurement the half-life of ${}^6\mathrm{He}$ has been remeasured to be $T_{1/2}=0.810\mathrm{}\pm 0.008\hspace{0.5em}\mathrm{s}.$ High statistical accuracy in the deuteron spectrum has been obtained that allowed a comparison of the shape of the deuteron spectrum to theoretical predictions.

In conventional calculations of fusion cross sections and barrier distributions, the nuclear potential is determined along the line joining the centers of the two nuclei. For deformed nuclei of finite size, this does not correspond to the minimum distance between the nuclear surfaces. Calculations are made using the minimum distance as the argument of the internucleus nuclear potential. The surface curvature correction to this potential is also included. These geometrical effects significantly change the near-barrier fusion cross sections and the shape of the barrier distribution.

In this paper, we present a complete set of polarization-transfer observables measured at 197 MeV in the quasifree region for $(\overrightarrow{p},\overrightarrow{n})$ reactions on ${}^2\mathrm{H}$ and ${}^{3,4}\mathrm{He}$ targets. Data were obtained at laboratory scattering angles of $13°,$ $24°,$ $37°,$ and $48°$ for the ${}^2\mathrm{H}$ target and at $13°$ and $37°$ for the ${}^{3,4}\mathrm{He}$ targets. The data span an energy-loss range up to 150 MeV, with a corresponding momentum-transfer range $q=0.75\mathrm{}–2.4\hspace{0.5em}{\mathrm{fm}}^{-1}.$ The polarization-transfer observables are used to calculate the center-of-mass polarization observables. The empirical results for the ${}^2\mathrm{H}$ target are compared to the observables obtained from the free nucleon-nucleon database and with Faddeev-type calculations. No discernible differences are observed in either the values of polarization-transfer observables or in the center-of-mass polarization observables among the three nuclei studied in this paper.

A complete set of polarization-transfer observables has been measured at 197 MeV in the quasifree region for the $(\overrightarrow{p},\overrightarrow{n})$ reactions on C, Ca, and Pb targets. Data have been obtained at laboratory scattering angles of $13°,$ $24°,$ $37°,$ and $48°,$ which span an energy-loss range up to 150 MeV, with a corresponding momentum-transfer range $q=0.75\mathrm{}–2.4\hspace{0.5em}{\mathrm{fm}}^{-1}.$ The empirical results are compared to the observables obtained from the free nucleon-nucleon data base. Derived spin-longitudinal and spin-transverse responses for Ca are compared with those previously obtained at 346 and 495 MeV incident energies.

Using the Mainz $48\mathrm{cm}\varnothing \times 64\mathrm{cm}$ NaI(Tl) detector and the segmented Göttingen recoil detector SENECA in coincidence, Compton scattering by the proton at ${\theta }_{\gamma }^{\mathrm{lab}}=136\mathrm{}°$ has been measured at MAMI (Mainz) in the energy range from 200 to 470 MeV. The new data confirm the previous observation that there is a systematic discrepancy between MAMI and LEGS (Brookhaven) data leading to different spin polarizabilities ${\gamma }_{\pi }=-38.7\pm 1.8$ and $-27.2\pm 3.1$ $(\times {10}^{-4}{\mathrm{fm}}^4),$ respectively.

The description of the short-range part of the nucleon-nucleon forces in terms of quark degrees of freedom is tested against experimental observables. We consider, for this purpose, a model where the short-range part of the forces is given by the quark cluster model and the long- and medium-range forces by well established meson exchanges. The investigation is performed using different quark cluster models coming from different sets of quark-quark interactions. The predictions of this model are compared not only with the phase shifts but also directly with the experimental observables. Agreement with the existing $\mathrm{pp}$ and $\mathrm{np}$ world set of data is poor. This suggests that the current description of the nucleon-nucleon interaction, at short distances, in the framework of the nonrelativistic quark models, is at present only qualitative.

Cross section, analyzing power, and spin transfer observables for ${p-}^3\mathrm{He}$ elastic scattering have been obtained using an 800-MeV polarized proton beam at the Los Alamos Meson Physics Facility (LAMPF). The results are compared with theoretical predictions for these observables using nonlocal optical potentials defined by full folding a complex nucleon-nucleon (NN) effective interaction with a ground state ${}^3\mathrm{He}$ wave function given by a large space, shell model nuclear structure calculation. The effective NN interaction has been derived from complex NN potentials that fit the (complex) NN scattering phase shifts at 800 MeV.

We study the possible existence of nonstrange dibaryons and tribaryons by solving the bound-state problem of the two- and three-body systems composed of nucleons and deltas. The two-body systems are $NN,$ $N\Delta ,$ and $\Delta \Delta ,$ while the three-body systems are $NNN,$ $\mathrm{NN}\Delta ,$ $N\Delta \Delta ,$ and $\Delta \Delta \Delta .$ We use as input the nonlocal $NN,$ $N\Delta ,$ and $\Delta \Delta$ potentials derived from the chiral quark cluster model by means of the resonating group method. We compare with previous results obtained from the local version based on the Born-Oppenheimer approximation.