Point-form relativistic quantum mechanics is applied to elastic electron-deuteron scattering. The deuteron is modeled using relativistic interactions that are scattering-equivalent to the nonrelativistic Argonne $v_{18}$ and Reid ’93 interactions. A point-form spectator approximation (PFSA) is introduced to define a conserved covariant current in terms of single-nucleon form factors. The PFSA is shown to provide an accurate description of data up to momentum transfers of $0.5\hspace{0.5em}{\mathrm{GeV}}^2,$ but falls below the data at higher momentum transfers. Results are sensitive to the nucleon form factor parametrization chosen, particularly to the neutron electric form factor.

The decay of the $K^{\pi }{=8\mathrm{}}^{-}$ isomer in ${}^{132}\mathrm{Ce}$ with an excitation energy of 2340.2 keV has been investigated using the ${}^{120}\mathrm{Sn}{(}^{16}\mathrm{O}{,4n)}^{132}\mathrm{Ce}$ reaction. A half-life of 9.4±0.3 ms was determined. Two new decay paths have been found in the deexcitation of this isomer. The hindrance factors for the $E1,$ $M2,$ and $E3\mathrm{}$ transitions deexciting the isomer have been determined. The decay properties of the $8^{-}$ isomers in the $N=74\mathrm{}$ isotones are discussed. A band mixing mechanism involving the ground state and $s$ band seems to be responsible for the behavior of the reduced hindrance factors of the $E1\mathrm{}$ transitions deexciting the $K^{\pi }{=8\mathrm{}}^{-}$ isomers in these isotones. A $K$ mixing, characteristic of the axially asymmetric nuclei, may account for the reduced hindrance factors of the $E3\mathrm{}$ transitions to the $5_{\gamma }^{+}$ states in ${}^{130}\mathrm{Ba}$ and ${}^{132}\mathrm{Ce}.$

The linear correlations between ground state gyromagnetic ratios and superallowed $\beta -\mathrm{d}\mathrm{e}\mathrm{c}\mathrm{a}\mathrm{y}$ transition strengths of mirror nuclei are reexamined in the light of more extensive experimental data. Predictions are made for the (as yet unmeasured) ground state magnetic moments of 11 nuclei in the mass range $45<~A<~59,$ using shell model calculations to resolve sign ambiguities. The linear correlations are tentatively extended to superallowed decays between excited states of mirror nuclei.

A new Coulomb breakup experiment was performed for ${}^7\mathrm{Li}$ with an improved experimental technique and theoretical treatment. Energy spectra of $\alpha$ particles and tritons were examined to find the signature of post-Coulomb acceleration in the breakup of ${}^7\mathrm{Li}$ at $E_{\alpha t}=0.\mathrm{}$ The data revealed the delayed nature of nonresonant breakup of astrophysical relevance that stems from quantum tunneling. Semiclassical discussions are presented of the lifetime of continuum states in ${}^7\mathrm{Li}$ and distortion of relative kinetic energies between $\alpha$ and t by post-Coulomb acceleration. Dynamical calculations of Coulomb breakup were performed by solving a time-dependent Schrödinger equation. A simple potential model of ${}^7\mathrm{Li}$ was employed. The dynamical calculations reasonably reproduced experimental cross sections for both resonant and nonresonant breakup with two key ingredients: higher order effects and mixture of $E1\mathrm{}$ and $E2\mathrm{}$ multipoles. Considering the dominant role of the first-order $E1\mathrm{}$ nature in adiabatic Coulomb breakup, cross sections in the $v_{\alpha }>~v_t$ branch at $7°$–$15°$ for ${}^{64}\mathrm{Zn}$ and ${}^{90}\mathrm{Zr}$ were used to deduce astrophysical S factors $S\left(E\right)\mathrm{}$ for $t(\alpha ,\gamma {)}^7\mathrm{Li}.$ They exhibit a moderate energy dependence at small energies. The strongly energy-dependent $S\left(E\right)\mathrm{}$ resulted from the previous Coulomb breakup experiment based on cross sections with $v_{\alpha }<~v_t;$ they are most likely Coulomb distorted and are revised in the present work.

Two multistring models implemented through the Monte Carlo codes FRITIOF and VENUS are used to analyze the data from proton-emulsion interactions at high energies. Both models are based on the concept of classical strings. However, the first model uses longitudinal excitation as a means of string formation, the subsequent string fragmentation following the Lund fragmentation scheme. The second model VENUS uses the color exchange or string flip mechanism for string formation and the string fragments into observable hadrons using an iterative fragmentation cascade. The analysis gives an interesting comparison between the data and predictions from the two models.

We study the nucleon-nucleon interaction in a chiral constituent quark model by using the resonating group method, convenient for treating the interaction between composite particles. The calculated phase shifts for the ${}^3{S}_1$ and ${}^1{S}_0$ channels show the presence of a strong repulsive core due to the combined effect of the quark interchange and the spin-flavor structure of the effective quark-quark interaction. Such a symmetry structure stems from the pseudoscalar meson exchange between the quarks and is a consequence of the spontaneous breaking of the chiral symmetry. We perform single and coupled channel calculations and show the role of coupling of the $\Delta \Delta$ and hidden color $\mathrm{CC}$ channels on the behavior of the phase shifts.

The breakup of ${}^{10,12}\mathrm{Be}$ into He clusters has been studied using the ${p,}^{12}\mathrm{C}{(}^{12}\mathrm{Be}{,}^6\mathrm{He}{,}^6\mathrm{He})$ and ${}^{12}\mathrm{C}{(}^{12}\mathrm{Be}{,}^4\mathrm{He}{,}^6\mathrm{He})$ inelastic scattering and two neutron transfer reactions with a 378 MeV ${}^{12}\mathrm{Be}$ beam incident on ${}^{12}\mathrm{C}$ and $({\mathrm{CH}}_2{)}_n$ targets. Evidence has been found for three new states in ${}^{10}\mathrm{Be}$ at excitation energies of 13.2, 14.8, and 16.1 MeV, which may be associated with a ${}^4\mathrm{He}{+}^6\mathrm{He}$ cluster structure. The evidence for He cluster states in ${}^{12}\mathrm{Be}$ in the excitation energy range 12 to 25 MeV is also discussed.

A preequilibrium process for the prefission neutron which is emitted before scission is calculated with the model of Feshbach, Kerman, and Koonin. A forward-peaked angular distribution of the neutron emission from ${}^{238}\mathrm{U}$ bombarded by 14 and 18 MeV neutrons is expressed with the statistical multistep compound process and the one-step direct process. The fission neutron energy spectra are calculated with the model of Madland and Nix, with some modifications by Ohsawa et al. The calculated total neutron emission spectra and their energy-angle distributions (double-differential cross sections) are compared with the experimental data, and a strength of the residual interaction $V_0$ is estimated. The comparisons of the calculations with the experimental data show that the 14 MeV data are well reproduced but the 18 MeV data are underestimated. Anisotropy is seen in the angle-differential fission spectra, and this is due to an existence of the prefission neutron.

Angular distributions for elastic and inelastic deuteron scattering on ${}^{12}\mathrm{C},$ ${}^{24}\mathrm{Mg},$ and ${}^{58}\mathrm{Ni}$ have been measured at a bombarding energy of 170 MeV. The data are analyzed in terms of the optical model. The extracted optical model parameters are compared to existing deuteron global optical potentials.

Pair correlation effects in the transfer processes have been investigated through an odd-even staggering in the measured yields of Q-value integrated multi-neutron transfer channels in the ${}^{62}\mathrm{Ni}{+}^{206}\mathrm{Pb}$ system at three bombarding energies close to the Coulomb barrier. The experimental results for these inclusive transfer data suggest a dominance of a sequential mechanism in the transfer process.

High energy photon emission rate from matter created in Pb+Pb collisions at CERN SPS energies is evaluated. The evolution of matter from the initial state up to freeze-out has been treated within the framework of (3+1) dimensional hydrodynamic expansion. We observe that the photon spectra measured by the WA98 experiment are well reproduced with hard QCD photons and photons from a thermal source with initial temperature $\sim 200\mathrm{MeV}.$ The effects of the spectral changes of hadrons with temperature on the photon emission rate and on the equation of state are studied. Photon yield for Au+Au collisions at RHIC energies is also estimated.

We derive a ${\mathrm{NN}}^{*}\mathrm{}\left(1440\right)\mathrm{}$ potential from a nonrelativistic quark-quark interaction and a quark cluster model for the baryons. By making use of the Born-Oppenheimer approximation, we examine quark Pauli correlations in detail. A comparison with the $\mathrm{NN}$ potential derived in the same framework is done. This makes it possible to emphasize the role of quark antisymmetry beyond baryon antisymmetry and to discuss the use of phenomenological ${\mathrm{NN}}^{*}\mathrm{}\left(1440\right)\mathrm{}$ baryonic potentials.

Faddeev equations for elastic $\mathrm{Nd}$ scattering have been solved using modern $\mathrm{NN}$ forces combined with the Tucson-Melbourne two-pion exchange three-nucleon force, with a modification thereof closer to chiral symmetry and the Urbana IX three-nucleon force. Theoretical predictions for the differential cross section and several spin observables using $\mathrm{NN}$ forces only and $\mathrm{NN}$ forces combined with three-nucleon force models are compared to each other and to the existing data. A wide range of energies from 3 to 200 MeV is covered. Especially at the higher energies striking three-nucleon force effects are found, some of which are supported by the still rare set of data, some of which are in conflict with data and thus very likely point to defects in those three-nucleon force models.

The decays of ${}^{119m}\mathrm{Cs}$ and ${}^{119g}\mathrm{Cs}$ to ${}^{119}\mathrm{Xe}$ have been studied on mass-separated samples, using $\gamma$-ray and internal conversion electron measurements. Several new low-lying levels have been established in the ${}^{119}\mathrm{Xe}$ level scheme. Half-life evaluations for ${}^{119m}\mathrm{Cs}$ and ${}^{119g}\mathrm{Cs}$ have been revisited. The results are compared with other experimental data known in light odd-mass xenon isotopes and with calculations performed in the frame of the multishell interacting boson-fermion model.

Gamma-ray cascades in the two- and three-valence-particle nuclei ${}^{134}\mathrm{Sb}$ and ${}^{135}\mathrm{Te}$ have been studied with Gammasphere using a ${}^{248}\mathrm{Cm}$ spontaneous fission source. Isotopic assignments were based in part on coincidences with γ rays from complementary Rh and Ru fission partners. The ${}^{134}\mathrm{Sb}$ and ${}^{135}\mathrm{Te}$ level schemes have been considerably extended, with placement of many new high-energy γ rays; delayed γ-ray coincidences observed across a 0.51-μs yrast isomer in ${}^{135}\mathrm{Te}$ were especially fruitful. The yrast level spectra of both nuclei are interpreted using empirical nucleon-nucleon interactions and compared with the known yrast excitations of their counterparts ${}^{210}\mathrm{Bi}$ and ${}^{211}\mathrm{Po}.$

Energy distributions for outgoing ${}^7\mathrm{Be}$ fragments from breakup of ${}^8\mathrm{B}$ on a ${}^{58}\mathrm{Ni}$ target have been measured at an incident energy of 25.75 MeV, which is below the Coulomb barrier. The data are compared with coupled-channels calculations that include higher-order couplings in the continuum.

We discuss calculations of three-body observables for the breakup of ${}^8\mathrm{B}$ on a ${}^{58}\mathrm{Ni}$ target at low energy using the coupled discretized continuum channels approach. Calculations of both the angular distribution of the ${}^7\mathrm{Be}$ fragments and their energy distributions are compared with those measured at several laboratory angles. In these observables there is interference between the breakup amplitudes from different spin-parity excitations of the projectile. The resulting angle and the energy distributions reveal the importance of the higher-order continuum state couplings for an understanding of the measurements.

The correlations between the charges emitted in the collision of $10.7A\mathrm{GeV}$ Au nuclei on emulsion targets are analyzed by a multistep model as follows: (i) Glauber scattering at the first stage of the interaction; (ii) dynamical evolution of highly excited fragments; and (iii) statistical decay of the excited residues. The combined model with soft equation of state parameters describes well such correlations, without any adjustments. A comparison between our results and the ones previously obtained by a cascade model indicates that dynamics play a very important role in determining correctly both the excitation energies and source sizes of fragments before final breakup.

We have calculated cross sections and branching ratios for neutrino-induced reactions on ${}^{208}\mathrm{Pb}$ and ${}^{56}\mathrm{Fe}$ for various supernova and accelerator-relevant neutrino spectra. This was motivated by the facts that lead and iron will be used on the one hand as target materials in future neutrino detectors and, on the other hand, have been and are still used as shielding materials in accelerator-based experiments. In particular we study the inclusive ${}^{56}\mathrm{Fe}({\nu }_e{,e}^{-}{)}^{56}\mathrm{Co}$ and ${}^{208}\mathrm{Pb}({\nu }_e{,e}^{-}{)}^{208}\mathrm{Bi}$ cross sections and calculate the neutron energy spectra following the decay of the daughter nuclei. These reactions give a potential background signal in the KARMEN and LSND experiment and are discussed as a detection scheme for supernova neutrinos in the proposed OMNIS and LAND detectors. We also study the neutron emission following the neutrino-induced neutral-current excitation of ${}^{56}\mathrm{Fe}$ and ${}^{208}\mathrm{Pb}.$

Gamma-ray lines from ${}^{103}\mathrm{Sn}$ have been identified for the first time using EUROBALL and ancillary detectors. The level scheme of ${}^{103}\mathrm{Sn}$ has been established by means of particle-gated γγ coincidences. The energy spacing between the $g_{7/2}$ and $d_{5/2}$ neutron single-particle orbitals is determined from the excited states in ${}^{103}\mathrm{Sn}.$