High-precision half-life determination for the superallowed [beta][superscript +] emitter [superscript 62]Ga

Publisher's version/PDFThe half-life of the superallowed [beta][superscript +] emitter [superscript 62]Ga has been measured at TRIUMF’s Isotope Separator and Accelerator facility using a fast-tape-transport system and 4[pi] continuous-flow gas proportional counter to detect the positrons from the decay of [superscript 62]Ga to the daughter [superscript 62]Zn. The result, T[subscript 1/2] = 116.100 [plus or minus] 0.025 ms, represents the most precise measurement to date (0.022%) for any superallowed [beta]-decay half-life. When combined with six previous measurements of the [superscript 62]Ga half-life, a new world average of T[subscript 1/2] = 116.121 [plus or minus] 0.021 ms is obtained. This new half-life measurement results in a 20% improvement in the precision of the [superscript 62]Ga superallowed f t value while reducing its mean by 0.9[sigma] to f t = 3074.3(12) s. The impact of this half-life measurement on precision tests of the CVC hypothesis and isospin symmetry breaking corrections for A [greater than or equal to] 62 superallowed decays is discussed