The predicted effects of final state interactions such as colour reconnecti
on are investigated by measuring properties of hadronic decays of W bosons,
recorded at a centre-of-mass energy of root s similar or equal to 182.7 Ge
V in the OPAL detector at LEP. Dependence on the modelling of hadronic W de
cays is avoided by comparing W+W- --> q (q) over bar q (q) over bar events
with the non-leptonic component of W+W- --> q (q) over bar'l<(nu)over bar>(
l) events. The scaled momentum distribution, its mean value, [x(p)], and th
at of the charged particle multiplicity, [n(ch)], are measured and found to
be consistent in the two channels. The measured differences are:
Delta[n(ch)] = [n(ch)(4q)] - 2[n(ch)(qql nu)] = + 0.7 +/- 0.8 +/- 0.6
Delta[x(p)] = [x(p)(4q)] - [x(p)(qql nu)] = (- 0.09 +/- 0.09 +/- 0.05) X 10
(-2)
In addition, measurements of rapidity and thrust are performed for W+W- -->
q (q) over bar'q (q) over bar' events. The data are described well by stan
dard QCD models and disfavour one model of colour reconnection within the A
RIADNE program. The current implementation of the Ellis-Geiger model of col
our reconnection is excluded. At the current level of statistical precision
no evidence for colour reconnection effects was found in the observables s
tudied. The predicted effect of colour reconnection on OPAL measurements of
M-W is also quantified in the context of models studied. (C) 1999 Publishe
d by Elsevier Science B.V. All rights reserved.