Particle pairs in the cranked Hartree-Fock-Bogoliubov approximation and the interacting boson model

The number projected HFB wave function is analyzed in terms of particle pairs. It is found that the S(J = 0) and D(J = 2) pairs have dominant probabilities in this wave function before the occurrence of backbending, which is clarified from the behaviour of the O(J = 12) and M(J = 10) pairs arising from the $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ level. After backbending the wave function can be described mainly in terms of the O and M pairs plus the core made of S and D pairs.     

Elementary excitations in vibrational nuclei

We propose to describe the entire collective spectrum of vibrational nuclei in terms of few enteracting elementary excitation modes. We discuss in detail the case in which only two elementary modes are important (the quadrupole d and the octupole f-bosons). We give explicit expressions for the energy levels and transition matrix elements.     

Can we see relativistic and quark effects in nuclear magnetic moments?

Many theoretical contributions to nuclear magnetic moments are reviewed with major attention to core polarisation and meson exchange currents. Experimental evidence is drawn from light isobaric mirror nuclei. Relativistic and quark contributions to nuclear magnetic moments are estimated and discussed.     

Effects of core polarization and exchange currents on the magnetic form factors of 0f 7/2 and 0g 9/2-shell nuclei

We have studied core polarization and exchange current effects on the magnetic form factors with the highest multipolarities allowed by the shell model:M 7 for⁴⁹Ti,⁵¹V, and⁵⁹Co, andM9 for⁸⁷Sr and⁹³Nb. One-pion exchange currents partially remove discrepancies between density-dependent Hartree-Fock-Bogoliubov calculations and experiments.     

First observation of the B1A1 state of SiH2 and SiD2 radicals by optical-optical double resonance spectroscopy

The B1A1 state of SiH2 and SiD2 was observed by the optical-optical double resonance technique for the first time. The electronic band origin of the B state of SiD2 was determined to be 27 214.11 cm(-1). A very clear exclusive behavior depending on the even/odd value of the bending vibrational quantum number was observed in the spectra, representing a quasilinear behavior of the B state. The barrier height to linearity was estimated to be approximately 125 cm(-1) by the quasilinear analysis of the bending vibrational level structure of SiD2.     

Shell model description of interacting bosons

The interacting boson model, describing collective states of even-even nuclei, is introduced as a drastic truncation of large scale shell model calculations. The shell model hamiltonian can be diagonalized by using a correspondence, or mapping, of the nucleon states in the truncated space into states obtained by coupling proton and neutron s- and d-bosons. The equivalent boson hamiltonian in a simple case is obtained and diagonalized. Eigenstates with definite proton-neutron symmetry (good F-spin) emerge for certain values of proton and neutron numbers. In general the situation is more complex but the results obtained follow closely the experimental data.     

Nuclear moments. Concluding remarks

Studies of nuclear magnetic moments and nuclear weak interactions discussed in this Conference are reviewed. The importance of configuration mixing and meson exchange currents is examined, and it is emphasized that the second order configuration mixing (tensor correlation) is essential for the understanding of these phenomena. Recent results concerning nuclear quadrupole moments reported in this Conference are also discussed. Finally, the pairing effect in metal clusters is pointed out and the importance of measuring their spins and magnetic moments is mentioned.     

Cyclodextrin-based isolation of Ostwald's metastable polymorphs occurring during crystallization

We describe a novel approach for the selective isolation of Ostwald's intermediate metastable polymorphs occurring during an early stage of crystallization, by utilizing the inclusion complex formed with a cyclic oligosaccharide derivative, 2,6-di-O-methyl-beta-cyclodextrin.     

Infrared vibrational autodetachment spectroscopy of microsolvated benzonitrile radical anions

Vibrational spectra of microsolvated benzonitrile radical anions (C6H5CN- -S; S = H2O and CH3OH) were measured by probing the electron detachment efficiency in the 3 microm region, representing resonance bands of autodetachment via OH stretching vibrations of the solvent molecules. The hydrogen-bonded OH band for both the cluster anions exhibited a large shift to the lower energy side with approximately 300 cm-1 compared to those for the corresponding neutral clusters. The solvent molecules are bound collinearly to the edge of the CN group of the benzonitrile anion in the cluster structures optimized with the density functional theory, in which the simulated vibrational energies are in good agreement with the observed band positions. Natural population analyses were performed for a qualitative implication in changes of solvent orientation upon electron attachment. Asymmetric band shapes depending on the vibrational modes are discussed with respect to dynamics of the autodetachment process from a theoretical aspect incorporated with density functional calculations.     

Picosecond IR-UV pump-probe study on the vibrational relaxation of phenol-ethylene hydrogen-bonded cluster: difference of relaxation route/rate between the donor and the acceptor site excitations

Picosecond time-resolved IR-UV pump-probe spectroscopy has been performed to study intracluster vibrational energy redistribution (ICVR) and vibrational predissociation (VP) for the OH and CH stretch vibrations of phenol-ethylene hydrogen-bonded cluster. The transient UV spectra after the picosecond IR pulse excitation of these modes were observed by 1+1 REMPI via S(1) with a picosecond UV pulse. We have focused on the difference of the energy flow routes and their rates between the donor (phenol) and the acceptor (ethylene) site. Though the transient UV spectra showed a similar broad feature for all the vibrations examined, the time profiles exhibited a remarkable site dependence, as well as substantial mode dependence. Especially, we found a large difference in the early stage of the IVR evolution and the rates, whereas the VP rates were very similar.