R. Barate et al., Measurement of the e(+)e(-)-> ZZ production cross section at centre-of-mass energies of 183 and 189 GeV, PHYS LETT B, 469(1-4), 1999, pp. 287-302
The e(+)e(-) --> ZZ cross section at root s = 182.7 and 188.6 GeV has been
measured using the ALEPH detector. A cut-based analysis yields cross sectio
n measurements of
sigma(ZZ)(182.7 GeV) = 0.11 +/- (0.16)(0.11) (stat.) +/- 0.04 (syst.) pb
and
sigma(ZZ)(188.6 GeV) = 0.69 +/- (0.13)(0.12) (stat.) +/- 0.03 (syst.) pb.
A neural network-based analysis yields
sigma(ZZ)(188.6 GeV) = 0.64 +/- (0.12)(0.11) (stat.) +/- 0.04 (syst.) pb.
These measurements are consistent with the Standard Model expectations. (C)
1999 Published by Elsevier Science B.V. All rights reserved.