ISSN:
1572-9540
Keywords:
leptonic and semi-leptonic decays
;
leptonic angular correlations
;
Cabbibo angle
;
nuclear β-decay
;
isospin mixing
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The positron–neutrino correlation in the 0+→0+ β-decay of 32Ar was measured at ISOLDE by analyzing the effect of lepton recoil on the shape of the narrow proton group following the super-allowed decay. Our result is consistent with the standard model prediction;for vanishing Fierz interference we find a=0.9989±0.0052±0.0039. Our result leads to improved constraints on scalar weak interactions. The positron–neutrino correlation in 33Ar decay was measured in the same experiment;for vanishing Fierz interference we find a=0.944±0.002±0.003. The 32Ar and 33Ar correlations, in combination with precision measurements of the half-lives, super-allowed branching ratios and beta endpoint energies, will determine the isospin impurities of the super-allowed transitions. These will provide useful tests of isospin-violation corrections used in deducing |Vud| which currently indicates non-unitarity of the KM matrix.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1012605731737
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