Abstract
A high-precision branching-ratio measurement for the superallowed decay of Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electron-positron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted particles; the 8 spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting rays that were emitted following Gamow-Teller and nonanalog Fermi decays of Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring -delayed conversion electrons. Twenty-three excited states were identified in Kr following detected Rb decays. A total of 58 -ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as . Combined with previous half-life and -value measurements, the superallowed branching ratio measured in this work leads to a superallowed value of 3082.8(65) s. Comparisons between this superallowed value and the world-average-corrected value, as well as the nonanalog Fermi branching ratios determined in this work, provide guidance for theoretical models of the isospin-symmetry-breaking corrections in this mass region.
6 More- Received 15 November 2012
DOI:https://doi.org/10.1103/PhysRevC.88.045501
©2013 American Physical Society