High-precision half-life determination for Na-21 using a 4 pi gas-proportional counter

Finlay, P; Laffoley, AT; Ball, GC; Bender, PC; Dunlop, MR; Dunlop, R; Hackman, G; Leslie, JR; MacLean, AD; Miller, D; Moukaddam, M; Olaizola, B; Severijns, Nathal; Smith, JK; Southall, D; Svensson, CE

doi:10.1103/PhysRevC.96.025501

High-precision half-life determination for Na-21 using a 4 pi gas-proportional counter

Author:

Finlay, P

Laffoley, AT ; Ball, GC ; Bender, PC ; Dunlop, MR ; Dunlop, R ; Hackman, G ; Leslie, JR ; MacLean, AD ; Miller, D ; Moukaddam, M ; Olaizola, B ; Severijns, Nathal ; Smith, JK ; Southall, D ; Svensson, CE

Keywords:

21Na, half-life, Science & Technology, Physical Sciences, Physics, Nuclear, Physics, LIVES, DECAYS, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 5106 Nuclear and plasma physics

Abstract:

A high-precision half-life measurement for the superallowed β + transition between the isospin T = 1/2 mirror nuclei 21Na and 21Ne has been performed at the TRIUMF-ISAC radioactive ion beam facility yielding T1/2 = 22.4506(33) s, a result that is a factor of 4 more precise than the previous world-average half-life for 21Na and represents the single most precisely determined half-life for a transition between mirror nuclei to date. The contribution to the uncertainty in the 21Na Ft mirror value due to the half-life is now reduced to the level of the nuclear structure-dependent theoretical corrections, leaving the branching ratio as the dominant experimental uncertainty.