Spreading Width for Decay out of a Superdeformed Band

The attenuation factor F responsible for the decay out of a superdeformed (SD) band is calculated with the help of a statistical model. This factor is given by 1/F = (1 + Gamma(down) / Gamma(S)). Here, Gamma(S) is the width for the collective E2 transition within the superdeformed band, and Gamma(down) is the spreading width which describes the mixing between a state in the SD band and the normally deformed (ND) states of equal spin. The attenuation factor F is independent of the statistical E1 decay widths Gamma(N) of the ND states provided that the Gamma(N) are much larger than both Gamma(down) and Gamma(S). This condition is generically met. Previously measured values of F are used to determine Gamma(down).Comment: Submitted to Physical Review Letter

HIE-ISOLDE: the Scientific Opportunities

The HIE-ISOLDE project aims at substantial improvements of the energy range, the intensity and the quality of the secondary radioactive beams produced at the ISOLDE facility at CERN. This report presents the questions within nuclear physics and related areas, including nuclear astrophysics, Standard Model tests and condensed matter physics, that scientists will be able to address at HIE-ISOLDE and gives specific examples of how the upgrades will improve the experimental conditions. The physics possibilities at HIE-ISOLDE were reviewed at the NuPAC meeting (Nuclear Physics and Astrophysics at CERN) held at CERN in October 2005; this report gives a more comprehensive overview and incorporates technical and scientific developments that have taken place since then

Alternative Interpretation of Sharply Rising E0 Strengths in Transitional Regions

It is shown that strong 0+2 -> 0+1 E0 transitions provide a clear signature of phase transitional behavior in finite nuclei. Calculations using the IBA show that these transition strengths exhibit a dramatic and robust increase in spherical-deformed shape transition regions, that this rise matches well the existing data, that the predictions of these E0 transitions remain large in deformed nuclei, and that these properties are intrinsic to the way that collectivity and deformation develop through the phase transitional region in the model, arising from the specific d-boson coherence in the wave functions, and that they do not necessarily require the explicit mixing of normal and intruder configurations from different IBA spaces.Comment: 6 pages, 3 figure

A 2D Electromagnetic PIC Code for Distributed Memory Parallel Computers

The two dimensional electrostatic plasma particle in cell (PIC) code described an [1] has been upgraded to a 2D electromagnetic PIC code running on the Caltech/JPL Mark IIIfp and the Intel iPSC/860 parallel MIMD computers. The code solves the complete time dependent Maxwell’s equations where the plasma responses, i.e., the charge and current density in the plasma, are evaluated by advancing in time the trajectories of ~ 10^6 particles in their self-consistent electromagnetic field. The field equations are solved in Fourier space. Parallelisation is achieved through domain decomposition in real and Fourier space. Results from a simulation showing a two-dimensional Alfèn wave filamentation instability are shown; these are the first simulations of this 2D Alfèn wave decay process

Use of Viscous medium to study anthelmintic drug action in Caenorhabditis elegans

Caenorhabditis elegans is an appealing tool for experimental evolution and for working with antiparasitic drugs, from understanding the molecular mechanisms of drug action and resistance to uncover new drug targets. We present a new methodology for studying the impact of antiparasitic drugs in C. elegans. Viscous medium was initially designed for C. elegans maintenance during long-term evolution experiments. Viscous medium provides a less structured environment than the standard nematode growth media agar, yet the bacteria food source remains suspended. Further, the Viscous medium offers the worm population enough support to move freely, mate, and reproduce at a rate comparable to standard agar cultures. Here, the Viscous medium was adapted for use in antiparasitic research. We observed a similar sensitivity of C. elegans to anthelmintic drugs as in standard liquid media and statistical difference to the standard agar media through a larval development assay. Using Viscous medium in C. elegans studies will considerably improve antiparasitic resistance research, and this medium could be used in studies aimed at understanding long-term multigenerational drug activity

Q-Value for the Fermi Beta-Decay of 46V

By comparing the Q-values for the 46Ti(3He,t)46V and 47Ti(3He,t)47}V reactions to the isobaric analog states the Q-value for the superallowed Fermi-decay of 46V has been determined as Q_{EC}(46V)=(7052.11+/-0.27) keV. The result is compatible with the values from two recent direct mass measurements but is at variance with the previously most precise reaction Q-value. As additional input quantity we have determined the neutron separation energy S_n(47Ti)=(8880.51+/-0.25) keV