Non-universal gauge boson Z ′ and the spin correlation of top quark pair production at e − e + colliders
Abstract
In the off-diagonal basis, we discuss the contributions of the non-universal gauge boson
Z
′
predicted by the topcolor-assisted technicolor (
TC2
) model to the spin configurations and the spin correlation observable of the top quark pair production via the process
e
−
e
+
→t
t
¯
. Our numerical results show that the production cross sections for the like-spin states, which vanish in the standard model, can be significantly large as
M
Z
′
≈
S
−
−
√
. With reasonable values of the
Z
′
mass
M
Z
′
and the coupling parameter
k
1
,
Z
′
exchange can generate large corrections to the spin correlation observable.