Browsing by Author "Andreoiu, C."

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    High-Precision Branching Ratio Measurement for the Superallowed + Emitter 74Rb
    (American Physical Society, 2013) Dunlop, R.; Ball, G.C.; Leslie, J.R.; Svensson, C.E.; Towner, I.S.; Andreoiu, C.; Chagnon-Lessard, S.; Chester, A.; Cross, D.S.; Finlay, P.; Garnsworthy, A.B.; Garrett, P.E.; Glister, J.; Hackman, G.; Hadinia, B.; Leach, K. G.; Rand, E.T.; Starosta, K.; Tardiff, E.R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S.W.; Zganjar, E.F.
    A high-precision branching-ratio measurement for the superallowed β + decay of 74Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electronpositron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted β particles; the 8π spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting γ rays that were emitted following Gamow-Teller and nonanalog Fermi β + decays of 74Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring β-delayed conversion electrons. Twenty-three excited states were identified in 74Kr following 8.241(4) × 108 detected 74Rb β decays. A total of 58 γ -ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as B0 = 99.545(31)%. Combined with previous half-life and Q-value measurements, the superallowed branching ratio measured in this work leads to a superallowed f t value of 3082.8(65) s. Comparisons between this superallowed f t value and the world-average-corrected Ft 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.