Precision half-life measurement ofF17

Abstract

We report a new precision half-life measurement of 17 F, using the β-counting station at the University of Notre Dame. The measured value of t new 1/2 = 64.402(42) s is in agreement with several past measurements and represents one of the most precise measurements to date. In anticipation of future measurements of the correlation parameters for the decay and using the new world average t world 1/2 = 64.398(61) s, we present a new estimate of the mixing ratio ρ for the mixed transition as well as the correlation parameters based on assuming Standard Model validity.

Resolving the discrepancy in the half-life of F20

“…The data analysis followed the well-established, widely used procedure outlined in [26], which was also used for previous half-life measurements using the β-counting station [23][24][25]. Data analysis was performed separately by Half-life two different group members.…”

Precision half-life measurement of Al25

“…Data analysis followed the well-established and widely used method described in detail in [23], which was also used for the precision half-life measurement of 17 F at the NSL [20]. The fitting procedures were tested against simulated data to ensure accuracy and probe for systematic uncertainties.…”

“…Using the Q EC -value from [31] and the parametrization from [32], a value of f v =508.520(32) was calculated. Then using the electron capture fraction P EC = 0.079, the branching ratio 99.151(31)% from [12], the Q EC -value from [31], the theoretical corrections δ R = 1.475 (20), and δ…”

“…Then, the beam of 25 Al was implanted in a thick tantalum foil in the NSL β-decay counting station [20,22]. The measurement was performed using the same procedure outlined in [20] except that the primary beam was turned off during the counting phase to avoid the presence of a cumulative background from the γ-rays emitted after the annihilation of the e + from the implanted 25 Al. The beam was deflected by applying a high voltage on a steerer plate upstream from the tandem.…”

“…Finally a new ion trapping experiment is currently being planned at the Nuclear Science Laboratory (NSL) of the University of Notre Dame [19]. Simultaneously, a new precision half-life measurement program on mirror transitions has also begun at the NSL [20]. As part of these efforts, several new radioactive ion beams are currently being developed and separated using the Twin Solenoid (TwinSol ) separator [21].…”