We report a measurement of the asymmetry of the first-forbidden transition from the 1/2+ ground state of Ne19 to the 1/2- level at 110 keV in F19. Using atomic beam methods to prepare a 100% polarized source of Ne19, we identify the 1/2+1/2- decays by the detection of the subsequent 110 keV gamma emitted in coincidence with a beta. The average asymmetry of the first-forbidden transition is measured to be A=17 12%. We simultaneously make an improved measurement of the branching ratio of the same transition and find =(1.13 0.09)×10-4 in good agreement with previous results. Our measurement is used to obtain an improved calibration of the isovector parity-mixing matrix element between the 1/2+ ground state of F19 and the 1/2- level at 110 keV.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics