https://doi.org/10.1140/epjc/s10052-009-1116-x
Regular Article - Theoretical Physics
O(α
s
) corrections to the polar angle dependence of the longitudinal spin–spin correlation asymmetry in
1
Institut für Physik, Johannes-Gutenberg-Universität, Staudinger Weg 7, 55099, Mainz, Germany
2
Loodus- ja Tehnoloogiateaduskond, Füüsika Instituut, Tartu Ülikool, Tähe 4, 51010, Tartu, Estonia
* e-mail: groote@thep.physik.uni-mainz.de
Received:
29
May
2009
Revised:
3
July
2009
Published online:
21
August
2009
We provide analytical results for the O(α
s
) corrections to the polar angle dependence of the longitudinal spin–spin correlation asymmetry in
. For top quark pair production the O(α
s
) corrections to the longitudinal spin–spin asymmetry are strongly polar angle dependent and can amount up to ≃4% in the q
2-range from above
threshold up to
. The O(α
s
) radiative corrections to the correlation asymmetry are below ≈1% in the forward direction where the cross section is largest. In the
case the O(α
s
) corrections reduce the asymmetry value from its m
b
=0 value of −100% to approximately −96% for q
2-values around the Z peak and are practically independent of the value of the polar angle θ. This reduction can be traced to finite anomalous contributions from residual mass effects which survive the m
b
→0 limit. We discuss the role of the anomalous contributions and the pattern of how they contribute to spin-flip and non-flip terms.
© Springer-Verlag , 2009
