[suny Bing 4/22/03 ] Consequences of a Large Top-quark Chiral Weak-moment

This talk concerns some theoretical patterns of the helicity amplitudes for t → W+b decay. The patterns involve both the standard model’s decay helicity amplitudes, ASM (λW+, λb), and the amplitudes A+ (λW+, λb) in the case of an additional tR → bL tensorial coupling of relative strength Λ+ = EW/2 ∼ 53GeV . Such an additional electroweak coupling would arise if the observed top-quark has a large chiral weak-transition-moment. The A+ amplitudes are interpreted as corresponding to the observed top-quark decays. Three tWb-transformations A+ = M ASM , ..., are used in simple characterization of the values of Λ+, mW/mt, and mb/mt. Measurement of the sign of the ηL = ±0.46(SM/+) helicity parameter, due to the large interference between the W longitudinal and transverse amplitudes, could exclude such a chiral weak-transition-moment in favor of the SM prediction.