https://doi.org/10.1140/epjc/s10052-013-2454-2
Regular Article - Theoretical Physics
Fully analytical O(α s ) results for on-shell and off-shell polarized W-boson decays into massive quark pairs
1
Loodus- ja Tehnoloogiateaduskond, Füüsika Instituut, Tartu Ülikool, Tähe 4, 51010, Tartu, Estonia
2
PRISMA Cluster of Excellence, Institut für Physik, Johannes-Gutenberg-Universität, Staudinger Weg 7, 55099, Mainz, Germany
* e-mail: groote@thep.physik.uni-mainz.de
Received:
8
January
2013
Revised:
23
April
2013
Published online:
29
May
2013
We provide analytical O(α
s
) results for the three polarized decay structure functions H
++, H
00 and H
−− that describe the decay of a polarized W boson into massive quark–antiquark pairs. As an application we consider the decay t→b+W
+ involving the helicity fractions ρ
mm
of the W
+ boson followed by the polarized decay 
described by the polarized decay structure functions H
mm
. We thereby determine the O(α
s
) polar angle decay distribution of the cascade decay process 
. As a second example we analyze quark mass and off-shell effects in the cascade decays 
and 
. For the decays 
and 
we find substantial deviations from the mass-zero approximation in particular in the vicinity of the threshold region.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
