MEASUREMENT OF ALPHA(S) FROM JET RATES IN DEEP-INELASTIC SCATTERING AT HERA

Jet production in deep inelastic scattering for 120 < Q(2) < 3600 GeV2 has been studied using data from an integrated luminosity of 3.2 pb(-1) collected with the ZEUS detector at HERA. Jets are identified with the JADE algorithm. A cut on the angular distribution of parton emission in the gamma(8)-parton centre-of-mass system minimises the experimental and theoretical uncertainties in the determination of the jet rates. The jet rates, when compared to O(alpha(s)(2)) perturbative QCD calculations, allow a precise determination of alpha(s)(Q) in three Q(2)-intervals. The values are consistent with a running of alpha(s)(Q), as expected from QCD. Extrapolating to Q = M(Z0) yields alpha(s)(M(Z0)) = 0.117 +/- 0.005 (stat)(-0.005)(+0.004) (syst(exp)) +/- 0.007 (syst(theory)). RI Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Gladilin, Leonid/B-5226-2011; Golubkov, Yury/E-1643-2012

Jet production in deep inelastic scattering for 120 < Q(2) < 3600 GeV2 has been studied using data from an integrated luminosity of 3.2 pb(-1) collected with the ZEUS detector at HERA. Jets are identified with the JADE algorithm. A cut on the angular distribution of parton emission in the gamma(8)-parton centre-of-mass system minimises the experimental and theoretical uncertainties in the determination of the jet rates. The jet rates, when compared to O(alpha(s)(2)) perturbative QCD calculations, allow a precise determination of alpha(s)(Q) in three Q(2)-intervals. The values are consistent with a running of alpha(s)(Q), as expected from QCD. Extrapolating to Q = M(Z0) yields alpha(s)(M(Z0)) = 0.117 +/- 0.005 (stat)(-0.005)(+0.004) (syst(exp)) +/- 0.007 (syst(theory)).