J. Breitweg et al., Measurement of dijet production in neutral current deep inelastic scattering at high Q(2) and determination of alpha(s), PHYS LETT B, 507(1-4), 2001, pp. 70-88
Dijet production has been studied in neutral current deep inelastic e(+)p s
cattering for 470 < Q(2) < 20000 GeV2 with the ZEUS detector at HERA using
an integrated luminosity of 38.4 pb(-1). Dijet differential cross sections
are presented in a kinematic region where both theoretical and experimental
uncertainties are small. Next-to-leading-order (NLO) QCD calculations desc
ribe the measured differential cross sections well. A QCD analysis of the m
easured dijet fraction as a function of Q(2) allows both a precise determin
ation of alpha (s)(M-z) and a test of the energy-scale dependence of the st
rong coupling constant. A detailed analysis provides an improved estimate o
f the uncertainties of the NLO QCD cross sections arising from the parton d
istribution functions of the proton. The value of cu,(Mz), as determined fr
om the QCD fit, is alpha (s)(M-z) = 0.1166 +/- 0.0019(stat.)(-0.0033)(+0.00
24)(exp.)(-0.0044)(+0.0057)(th.). (C) 2001 Elsevier Science B.V. All rights
reserved.