Search for Wobbling Excitations in Hf Nuclei: Are the SD Bands Triaxial?

Two Gammasphere experiments have been performed in order to establish the possible triaxial nature of strongly deformed (SD) bands in174Hf. A lifetime measurement confirmed the large deformation of the four previously observed bands in this nucleus. In addition, a thin-target, high-statistics experiment was carried out to search for linking transitions between the SD bands. No such transitions, which represent an experimental signature for wobbling modes, were observed. Four new SD bands were found in174Hf together with a single SD band in173Hf. These results indicate that the strongly deformed sequences of N ≈ 102 Hf isotopes behave differently than the TSD bands found in Lu nuclei near N = 92. The interpretation of these bands in terms of possible stable triaxial deformation is confronted with the experimental findings and UC predictions

A Hybrid Experiment to Search for Beauty Particles

We give here a detailed description of experiment WA75, which was performed at CERN to search for beauty particles. Events containing at least one muon with a high momentum transverse to the beam direction were selected; then the primary interactions and decay vertices, located in stacks of nuclear research emulsions, were examined and analysed. The various parts of the apparatus are described and the off-line analysis and search in emulsion are discussed. An estimate is made of the sensitivity of the experiment to beauty- and charmed-particle production.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Diffraction dissociation of nuclei in 450-GeV/c proton - nucleus collisions

Diffractive dissociation of nuclei (Be, Al, W) in collisions with 450 GeV/c protons,pA→pX, has been measured with the HELIOS spectrometer at the CERN Super Proton synchrotron. The dependence of the single-diffraction cross-section on the nuclear massA can be parametrized as σSD mb×A 0.35±0.02, showing the peripheral nature of the process. The differential cross-section dσSD=(3.8±0.3)mb ×A 0.35±0.02, is exponential with the slope parameter, increasing from 6.2±0.4 (GeV/c)−2 for beryllium to 7.9±0.5 (GeV/c)−2 for tungsten. The slope parameter also increases with increasing massM X of the diffractively produced state. The rapidity, multiplicity, and transverse-momentum distributions of the particles of the diffractively produced stateX show a longitudinal phase-space population and are remarkably insensitive to the nuclear mass. This, together with theA 1/3 dependence of σSD, suggests that the dominant process of nuclear diffractive excitation is the dissociation of single nucleons