Left-handed nuclei

The orientation of the angular momentum vector with respect to the triaxial density distribution selects a left-handed or right-handed system principal axes. This breaking of chiral symmetry manifests itself as pairs of nearly identical $\Delta I=1$-bands. The chiral structures combine high-j particles and high-j holes with a triaxial rotor. Tilted axis cranking calculations predict the existence of such configurations in different mass regions. There is experimental evidence in odd-odd nuclei around mass 134. The quantized motion of the angular momentum vector between the left- and right-handed configurations, which causes the splitting between the chiral sister bands, can be classified as tunneling (chiral rotors) or oscillation (chiral vibrators).Comment: Invited lecture at the Conference on Frontiers of Nuclear Structure, Berkeley, 200

A hybrid version of the tilted axis cranking model and its application to ^{128}Ba

A hybrid version the deformed nuclear potential is suggested, which combines a spherical Woods Saxon potential with a deformed Nilsson potential. It removes the problems of the conventional Nilsson potential in the mass 130 region. Based on the hybrid potential, tilted axis cranking calculations are carried out for the magnetic dipole band in ^{128}Ba.Comment: 10 pages 6 figure

Magnetocaloric Studies of the Peak Effect in Nb

We report a magnetocaloric study of the peak effect and Bragg glass transition in a Nb single crystal. The thermomagnetic effects due to vortex flow into and out of the sample are measured. The magnetocaloric signature of the peak effect anomaly is identified. It is found that the peak effect disappears in magnetocaloric measurements at fields significantly higher than those reported in previous ac-susceptometry measurements. Investigation of the superconducting to normal transition reveals that the disappearance of the bulk peak effect is related to inhomogeneity broadening of the superconducting transition. The emerging picture also explains the concurrent disappearance of the peak effect and surface superconductivity, which was reported previously in the sample under investigation. Based on our findings we discuss the possibilities of multicriticality associated with the disappearance of the peak effect.Comment: 30 pages, 10 figure