Azimuthal correlation between the $({\vec{p}}_l,{\vec{p}}_{X_b})$ and $({\vec{p}}_l,{\vec{P}}_t)$ planes in the semileptonic rest frame decay of a polarized top quark: An $O({\alpha }_s)$ effect

Abstract

The azimuthal correlation between the planes formed by the vectors $({\vec{p}}_{\ell },{\vec{p}}_{X_b})$ and $({\vec{p}}_{\ell },{\vec{P}}_t)$ in the semileptonic rest frame decay of a polarized top quark $t(\uparrow )\to X_b+l^{+}+{\nu }_{\ell }$ belongs to a class of polarization observables involving the top quark which vanish at the Born term level in the standard model. We determine the next--to--leading order QCD corrections to the afore-mentioned azimuthal correlation and compare the result to the corresponding contribution of a non--standard--model right--chiral quark current.

Comments: latex, 12 pages with 2 figures in the text, typos removed,comment and references added, replaced with published version