TY - JOUR
T1 - Test of time-reversal invariance and measurements of positron and neutrino asymmetries in polarized Ne19 beta decay
AU - Calaprice, Frank
AU - Commins, Eugene D.
AU - Gibbs, Hyatt M.
AU - Wick, Gerald L.
AU - Dobson, David A.
PY - 1969/12/1
Y1 - 1969/12/1
N2 - We present a comprehensive discussion of an experiment, previously reported, to test time-reversal (T) invariance in the β decay of Ne19. The "time-reversal" coefficient D, as well as the neutrino and positron asymmetry coefficients B and A, respectively, is measured, with results as follows: D=+0.002±0.014, B=-0.90±0.13, and A=-0.039±0.002. The value of D, based on 30 000 events, is consistent with T invariance: T invariance implies D=0, since final-state corrections to D are negligible. The atomic-beam method is used to form a nuclear-spin polarized beam of Ne19 atoms in the S01 ground state. Coefficients D and B are measured by observing correlations between the positron and recoil ion F-19 (in delayed coincidence) with respect to the Ne19 spin polarization, from decays in flight. The beam terminates its flight in a cell where Ne19 atoms are captured and remain for approximately 3 sec but suffer no significant depolarization. Positrons emitted parallel and antiparallel to the spin by Ne19 decaying in the cell are counted to measure β. The results of our measurements are compared with similar observations of the A decay of polarized neutrons.
AB - We present a comprehensive discussion of an experiment, previously reported, to test time-reversal (T) invariance in the β decay of Ne19. The "time-reversal" coefficient D, as well as the neutrino and positron asymmetry coefficients B and A, respectively, is measured, with results as follows: D=+0.002±0.014, B=-0.90±0.13, and A=-0.039±0.002. The value of D, based on 30 000 events, is consistent with T invariance: T invariance implies D=0, since final-state corrections to D are negligible. The atomic-beam method is used to form a nuclear-spin polarized beam of Ne19 atoms in the S01 ground state. Coefficients D and B are measured by observing correlations between the positron and recoil ion F-19 (in delayed coincidence) with respect to the Ne19 spin polarization, from decays in flight. The beam terminates its flight in a cell where Ne19 atoms are captured and remain for approximately 3 sec but suffer no significant depolarization. Positrons emitted parallel and antiparallel to the spin by Ne19 decaying in the cell are counted to measure β. The results of our measurements are compared with similar observations of the A decay of polarized neutrons.
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U2 - 10.1103/PhysRev.184.1117
DO - 10.1103/PhysRev.184.1117
M3 - Article
AN - SCOPUS:34249278187
SN - 0031-899X
VL - 184
SP - 1117
EP - 1129
JO - Physical Review
JF - Physical Review
IS - 4
ER -