Search

The WITCH-experiment will measure the energy spectrum of the recoiling daughter ions in beta decay to search for non-standard scalar and tensor type interaction. To facilitate this a Penning trap is used to store the radioactive ions. Thus the recoil ions can leave the source without any energy loss and their energy can be probed by the subsequent retardation spectrometer. The experiment is being set up at present at ISOLDE/CERN. The principle and the status of the WITCH-experiment will be presented. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The experiment described here will search for deviations from the V-A structure of the standard electroweak model. It is based on measuring the recoil energy spectrum in nuclear beta decay which is determined by the etectron-neutrino angular corretation. For pure Fermi decays this is exactly known in the standard model and any deviation will point to additional scalar interaction. The experiment consists of a Penning trap coupled to a retardation spectrometer to measure the energy of the recoiling daughter nuclei. The current status will be presented. [ABSTRACT FROM AUTHOR]

A non-zero value of the R-correlation coefficient due to the e - polarization component, perpendicular to the plane spanned by the spin of the decaying neutron and the electron momentum, would signal a violation of time reversal symmetry and thus physics beyond the Standard Model. The value of the N-correlation coefficient, given by the transverse e - polarization component within that plane, is expected to be finite. The measurement of N serves as an important systematic check of the apparatus for the R-measurement. The first phase of data taking has been completed. Preliminary results from a limited data sample show no deviations from the Standard Model predictions. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We report on a recent experiment searching for right-handed currents in the [sup 118]Sb nuclear β-decay. The correlation between the spin polarization and the βemission asymmetry of the positrons from the [sup 118]Sb decay is sensitive to the helicity structure of the weak interaction. A precision measurement of this correlation improves the limit on right-handed currents in β-decay. [ABSTRACT FROM AUTHOR]