New limit of the G-parity irregular weak nucleon current detected in {beta} decays of spin aligned {sup 12}B and {sup 12}N
- Department of Physics, Osaka University, I-1 Machikaneyama, Toyonaka, Osaka 560 (Japan)
- Department of Physics, Osaka Kyoiku University, 4-698-1 Asahigaoka, Kashiwara, Osaka 582 (Japan)
- Department of Physics, Josai International University, I Gumyo, Togane, Chiba 283 (Japan)
The G-parity irregular induced tensor form factor in the weak nucleon axial vector current has been precisely determined by measuring the alignment correlation terms in the {beta}-ray angular distributions of the purely spin aligned mirror pair {sup 12}B(I{sup {pi}}=1{sup +},T{sub 1/2}=20.2 ms) and {sup 12}N(I{sup {pi}}=1{sup +},T{sub 1/2}=11.0 ms) in order to place a new limit on the applicability of the G-parity conservation law. The coefficient of the induced tensor term was determined to be 2Mf{sub T}/f{sub A}=-0.15{+-}0.12{+-}0.05(theor.) in 90% confidence level. The obtained 2Mf{sub T}/f{sub A} is vanishingly small and is consistent with the theoretical prediction based on QCD in the framework of which 2Mf{sub T}/f{sub A} is proportional to the mass difference between up and down quarks. Also we set constraints on the KDR parameters from the present result together with the results of correlation type experiments in the mass A=8 and 20 systems as {zeta}=-(0.12{+-}0.15)x10{sup -3} MeV{sup -1} and {lambda}=+(0.30{+-}0.89)x10{sup -3} in 1{sigma} level.
- OSTI ID:
- 20618830
- Journal Information:
- AIP Conference Proceedings, Vol. 610, Issue 1; Conference: INPC 2001: International nuclear physics conference on nuclear physics in the 21st century, Berkeley, CA (United States), 30 Jul - 3 Aug 2001; Other Information: DOI: 10.1063/1.1470280; (c) 2002 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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