B. Abbott et al., Measurement of the angular distribution of electrons from W -> e nu decaysobserved in p(p)over-bar collisions at root s=1.8 TeV - art. no. 072001, PHYS REV D, 6307(7), 2001, pp. 2001
We present the first measurement of the electron angular distribution param
eter alpha (2) in W-->e nu events produced in proton-antiproton collisions
as a function of the W boson transverse momentum. Our analysis is based on
data collected using the D empty set detector during the 1994-1995 Fermilab
Tevatron run. We compare our results with next-to-leadiog order perturbati
ve QCD, which predicts an angular distribution of (1 +/- alpha (1) cos thet
a* + alpha (2) cos(2) theta*), whew theta* is the polar angle of the electr
on in the Collins-Soper frame. In the presence of QCD corrections, the para
meters alpha (1) and alpha (2) become functions of p(T)(W), the W boson tra
nsverse momentum. This measurement provides a test of next-to-leading order
QCD corrections which are a non negligible contribution to the W boson mas
s measurement.