Inclusive jet cross sections in the Breit frame in neutral current deep inelastic scattering at HERA and determination of alpha(s).

The ZEUS collaboration Chekanov, S. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 547 (2002) 164-180, 2002.
Inspire Record 593409 DOI 10.17182/hepdata.46572

Inclusive jet differential cross sections have been measured in neutral current deep inelastic e+p scattering for boson virtualities Q**2>125 GeV**2. The data were taken using the ZEUS detector at HERA and correspond to an integrated luminosity of 38.6 pb-1. Jets were identified in the Breit frame using the longitudinally invariant K_T cluster algorithm. Measurements of differential inclusive jet cross sections are presented as functions of jet transverse energy (E_T,jet), jet pseudorapidity and Q**2, for jets with E_T,jet>8 GeV. Next-to-leading-order QCD calculations agree well with the measurements both at high Q**2 and high E_T,jet. The value of alpha_s(M_Z), determined from an analysis of dsigma/dQ**2 for Q**2>500 GeV**2, is alpha_s(M_Z) = 0.1212 +/- 0.0017 (stat.) +0.0023 / -0.0031 (syst.) +0.0028 / -0.0027 (th.).

9 data tables

Inclusive jet cross section DSIG/DQ**2 for jets of hadrons in the Breit frame.

Inclusive jet cross section DSIG/DET for jets of hadrons in the Breit frame.

Inclusive jet cross section DSIG/DETARAP for jets of hadrons in the Breit frame.

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Measurement of dijet production in neutral current deep inelastic scattering at high Q**2 and determination of alpha(s).

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Phys.Lett.B 507 (2001) 70-88, 2001.
Inspire Record 553352 DOI 10.17182/hepdata.46870

Dijet production has been studied in neutral current deep inelastic e+p scattering for 470 < Q**2 < 20000 GeV**2 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 describe the measured differential cross sections well. A QCD analysis of the measured dijet fraction as a function of Q**2 allows both a precise determination of alpha_s(M_Z) and a test of the energy-scale dependence of the strong coupling constant. A detailed analysis provides an improved estimate of the uncertainties of the NLO QCD cross sections arising from the parton distribution functions of the proton. The value of alpha_s(M_Z), as determined from the QCD fit, is alpha_s(M_Z) = 0.1166 +- 0.0019 (stat.) {+ 0.0024}_{-0.0033} (exp.)} {+ 0.0057}_{- 0.0044} (th.).

13 data tables

The differential dijet cross section dsig/dZP1.

The differential dijet cross section dsig/dlog10(x).

The differential dijet cross section dsig/dlog10(xi).

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