TY - JOUR
T1 - Search for the G-parity irregular term in weak nucleon currents extracted from mirror beta decays in the mass 8 system
AU - Sumikama, T.
AU - Matsuta, K.
AU - Nagatomo, T.
AU - Ogura, M.
AU - Iwakoshi, T.
AU - Nakashima, Y.
AU - Fujiwara, H.
AU - Fukuda, M.
AU - Mihara, M.
AU - Minamisono, K.
AU - Yamaguchi, T.
AU - Minamisono, T.
N1 - Funding Information:
We would like to thank R.D. McKeown at California Institute of Technology for providing their data tables and for the valuable advice. T.S. acknowledges the Special Postdoctoral Researcher Program of RIKEN for the financial support.
PY - 2008/6/26
Y1 - 2008/6/26
N2 - The alignment correlation terms in the β-ray angular distributions from purely spin aligned 8Li and 8B have been measured to search for the G-parity violating induced tensor term gII in the weak nucleon currents. The gII was extracted from the present alignment correlation terms, combined with the known β - α angular correlation terms and weak magnetism. This analysis permits an experimental determination of all the matrix elements necessary to extract gII. As a result, the induced tensor term was extracted as gII / gA = - 0.28 ± 0.28 (stat.) ± 0.15 (syst.) at a 1σ (68%) level. The present data and the data in the mass A = 12 and 20 systems were analyzed under the KDR model in which medium effects including the off-shell effect and meson exchange current were taken into account. We determined the 1-body contribution to be ζ = - (0.13 ± 0.13) × 10-3 MeV-1 and the 2-body contribution to be λ = + (0.27 ± 0.97) × 10-3 at a 1σ level.
AB - The alignment correlation terms in the β-ray angular distributions from purely spin aligned 8Li and 8B have been measured to search for the G-parity violating induced tensor term gII in the weak nucleon currents. The gII was extracted from the present alignment correlation terms, combined with the known β - α angular correlation terms and weak magnetism. This analysis permits an experimental determination of all the matrix elements necessary to extract gII. As a result, the induced tensor term was extracted as gII / gA = - 0.28 ± 0.28 (stat.) ± 0.15 (syst.) at a 1σ (68%) level. The present data and the data in the mass A = 12 and 20 systems were analyzed under the KDR model in which medium effects including the off-shell effect and meson exchange current were taken into account. We determined the 1-body contribution to be ζ = - (0.13 ± 0.13) × 10-3 MeV-1 and the 2-body contribution to be λ = + (0.27 ± 0.97) × 10-3 at a 1σ level.
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U2 - 10.1016/j.physletb.2008.05.049
DO - 10.1016/j.physletb.2008.05.049
M3 - Article
AN - SCOPUS:44749090389
VL - 664
SP - 235
EP - 240
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
SN - 0370-2693
IS - 4-5
ER -