The axial vector coupling constants of the β decay processes of the neutron and hyperon are calculated in SU(3) chiral color dielectric model (CCDM). Using these axial coupling constants of the neutron and hyperon, in the CCDM we calculate the integrals of the spin-dependent structure functions for the proton and neutron. Our result is similar to the results obtained by MIT bag and cloudy bag models (CBM).

The spectral distribution method with modified Kuo-Brown interaction is extended to the study of the upper half as well as to odd-$A$ nuclei, of the $\mathrm{fp}$ shell. The calculations show similar success to that obtained for the lower half.

We study one- and two-neutron transfer probabilities in heavy-ion reactions within a semiclassical model. As in the case of the already studied proton transfer reactions, the interplay between absorption and tunneling effects qualitatively reproduces the overall properties of these probabilities and in particular the so-called slope anomaly observed in these reactions.

Previous approaches to the photoproduction and electroproduction of strangeness off the proton, based upon effective hadronic Lagrangians, are extended here to incorporate the so-called off-shell effects inherent to the fermions with spin $>~3/2.$ A formalism for intermediate-state, spin-3/2, nucleonic, and hyperonic resonances is presented and applied to the processes $\gamma \overrightarrow{p}{K}^{+}\Lambda ,$ for $E_{\gamma }^{\mathrm{lab}}<~$2.5 GeV, $e\overrightarrow{p}{e}^{\prime }{K}^{+}\Lambda ,$ as well as the branching ratio for the crossed channel reaction $K^{-}\overrightarrow{p}\gamma \Lambda ,$ with stopped kaons. The sensitivity, from moderate to significant, of various observables to such effects are discussed.

A class of nucleon-nucleon interactions which are exactly phase equivalent to a given realistic nucleon-nucleon interaction is exhibited. These interactions have the property that the rms radius of the deuteron can be made arbitrarily large without changing the deuteron binding energy or any of the nucleon-nucleon scattering matrix elements. With this construction it is possible to find realistic interactions that do not obey the linear relation between the rms radius and the triplet scattering length observed by Klarsfeld et al.. The interpretation of this result is discussed.

A unified description of $\mathrm{NN}$ and $\pi N$ elastic scattering is presented in the framework of the one solitary boson exchange potential (OSBEP). This model already successfully applied to analyze $\mathrm{NN}$ scattering is now extended to describe $\pi N$ scattering while also improving its accuracy in the $\mathrm{NN}$ domain. We demonstrate the importance of regularization of $\pi N$ scattering amplitudes involving $\Delta$ isobars and derivative meson-nucleon couplings, as this model always yields finite amplitudes without recourse to phenomenological form factors. We find an empirical scaling relation of the meson self-interaction coupling constants consistent with that previously found in the study of $\mathrm{NN}$ scattering. Finally, we demonstrate that the OSBEP model does not contradict the soft-pion theorems of $\pi N$ scattering.

A study of superdeformed band population at very high angular momenta was undertaken with the reactions ${}^{76}{\mathrm{G}\mathrm{e}+}^{76}\mathrm{Ge}$ and ${}^{28}{\mathrm{S}\mathrm{i}+}^{124}\mathrm{Sn}.$ Both reactions formed the compound nucleus ${}^{152}\mathrm{Gd}$ at an excitation energy of 87 MeV. Relative to normally deformed states, the yrast superdeformed band in the residual nucleus ${}^{147}\mathrm{Gd}$ was found to be populated $4.6\pm 0.2$ times more strongly for the mass-symmetric reaction compared to the mass-asymmetric reaction. Such a large difference in the population was not expected. Also, the superdeformed continuum feeding the yrast superdeformed states in ${}^{147}\mathrm{Gd}$ was found to be at least 12 times stronger for the mass-symmetric reaction.

The isospin mirror of the $J^{\pi }{=3/2\mathrm{}}^{+}$ ${}^{18}\mathrm{F}+p$ resonance at $E_x=7.070\mathrm{}\mathrm{MeV}$ in ${}^{19}\mathrm{Ne}$ has been measured in ${}^{19}\mathrm{F}$ via the ${}^{15}{\mathrm{N}(\mathrm{\alpha },\mathrm{\gamma })}^{19}\mathrm{F}$ reaction using the RHINOCEROS windowless gas target at the Stuttgart 4-MV Dynamitron facility. This resonance is measured to have the following properties: $E_x=7.101\mathrm{}\pm 0.001\mathrm{MeV},$ ${\Gamma }_{\mathrm{tot}}=28\mathrm{}\pm 1\mathrm{keV},$ and a strength of $\omega \gamma =0.77\mathrm{}\pm 0.11\mathrm{eV}$ (corresponding to ${\Gamma }_{\gamma }=0.39\mathrm{}\pm 0.06\mathrm{eV}$).

Exclusive studies of sideways-peaked angular distributions for intermediate-mass fragments (IMFs) produced in hadron-induced reactions have been performed with the Indiana silicon sphere (ISiS) detector array. The effect becomes prominent for beam momenta above about $10\mathrm{GeV}/c.\mathrm{}$ Both the magnitude of the effect and the peak angle increase as a function of fragment multiplicity and charge. When gated on IMF kinetic energy, the angular distributions evolve from forward peaked to nearly isotropic as the fragment energy decreases. Fragment-fragment correlation studies show no evidence for a preferred angle that might signal a fast dynamic breakup mechanism. Moving-source and intranuclear cascade simulations suggest a possible kinematic origin arising from significant transverse momentum imparted to the recoil nucleus during the fast cascade. A two-step cascade and statistical multifragmentation calculation is consistent with the data.

Any-order pion inclusive distributions for a chaotic source in high energy collisions are given, which can be used in both the theory and experiment to analyze the any-order pion interferometry. Multipion correlation effects on the two-pion and three-pion interferometry are discussed.

The Arrhenius-type correlations of the binomial probability $p$ and the excitation energy $E^{*}$ that is characteristic for a proper statistical multifragmentation can exist in the experimental data even as a correlation between the binomial probability $p$ and the transverse energy $E_t.$ This is due to the effect of the experimental filter used.

A systematic comparison of different isotopic temperatures with the thermodynamical temperature of a multifragment system is made on the basis of the statistical multifragmentation model. It is demonstrated that isotopic temperatures are strongly affected by the secondary decays of hot primary fragments and the population of particle-stable excited states in final fragments. The He-Li temperatures, measured recently by the ALADIN group, are reproduced fairly well both as a function of excitation energy and bound charge. Our analysis confirms the anomaly in the nuclear caloric curve.

We demonstrate a new approach to the analysis of extensive multienergy data. For the case of ${d+}^4\mathrm{He},$ we produce a phase shift analysis covering the energy range 3–11 MeV. The key idea is the use of a new technique for data-to-potential inversion which yields potentials that reproduce the data simultaneously over a range of energies. It thus effectively regularizes the extraction of phase shifts from diverse, incomplete, and possibly somewhat contradictory data sets. In doing so, it will provide guidance to experimentalists as to what further measurements should be made. This study is limited to vector spin observables and spin-orbit interactions. We discuss alternative ways in which the theory can be implemented and which provide insight into the ambiguity problems. We compare the extrapolation of these solutions to other energies. Majorana terms are presented for each potential component.

It is shown that because of a dominance of $\mathrm{np}$-pair transfer mechanisms of backward elastic ${p-}^3\mathrm{He}$ scattering for incident proton kinetic energies $T_p>1\mathrm{}\mathrm{GeV}$ the cross section of this process is defined mainly by the values of the Faddeev component of the wave function of the ${}^3\mathrm{He}$ nucleus, ${\phi }^{23}({\mathbf{q}}_{23},{\mathbf{p}}_1),$ at high relative momenta $q_{23}>0.6\mathrm{}\mathrm{GeV}/c$ of the $\mathrm{NN}$ pair in the ${}^1{S}_0$ state and at low spectator momenta $p_1\sim 0-0.2\mathrm{GeV}/c.\mathrm{}$

We show how the gauge-invariance formulation given by Haberzettl is implemented in practice for photoproduction amplitudes at tree level with form factors describing composite nucleons. We demonstrate that, in contrast to Ohta’s gauge-invariance prescription, this formalism allows electric current contributions to be multiplied by a form factor, i.e., it does not require that they be treated like bare currents. While different in detail, this nevertheless lends support to previous ad hoc approaches which multiply the Born amplitudes by an overall form factor. Numerical results for kaon photoproduction off the nucleon are given. They show that the gauge procedure by Haberzettl leads to much improved ${\chi }^2$ values compared to Ohta’s prescription.

Based on the relativistic mean field (RMF) approach the existence of the broken pseudospin symmetry is investigated. Both spherical RMF and constrained deformed RMF calculations are carried out employing realistic Lagrangian parameters for spherical and for deformed sample nuclei. The quasidegenerate pseudospin doublets are confirmed to exist near the Fermi surface for both spherical and deformed nuclei.

A first level scheme of ${}^{68}\mathrm{Se}$ with five states up to 4.2 MeV excitation energy and tentative spins $6^{+}$ and $7^{-}$ has been established from γγγ coincidences measured with six EUROBALL Cluster detectors in close geometry. The level scheme is interpreted in comparison with neutron deficient nuclei of the $A\approx 70$ region and cranking model calculations. In a similar experiment a triple coincidence between the ${}^{72}\mathrm{Kr}$ transitions 710, 611, and 792 keV has been proven.

The nuclear sigma term is calculated including the nuclear matrix element of the derivative of the $\mathrm{NN}$ interaction with respect to the quark mass, $m_q\partial V_{\mathrm{NN}}/\partial m_q.$ The $\mathrm{NN}$ potential is evaluated in the Skyrmion-Skyrmion picture within the quantized product ansatz. The contribution of the $\mathrm{NN}$ potential to the nuclear sigma term provides repulsion to the pion-nucleus interaction. The strength of the $s$-wave pion-nucleus optical potential is estimated including such a contribution. The results are consistent with the analysis of the experimental data.

The scalar-isoscalar field of an effective chiral Lagrangian transforms differently in either linear or nonlinear frameworks: in the former case it is the counterpart of the pion whereas in the latter it is chiral invariant on its own. We compare the predictions from these two models for nucleon interactions and find results which are identical for two-body and rather different for three-body potentials. Some qualitative features of three-body interactions are discussed.