Jet substructure and differential cross sections for jets produced in the photoproduction and deep inelastic ep scattering regimes have been measured with the ZEUS detector at HERA using an integrated luminosity of 82.2 pb−182.2 pb−1. The substructure of jets has been studied in terms of the jet shape and subjet multiplicity for jets with transverse energies View the MathML sourceETjet>17 GeV. The data are well described by the QCD calculations. The jet shape and subjet multiplicity are used to tag gluon- and quark-initiated jets. Jet cross sections as functions of View the MathML sourceETjet, jet pseudorapidity, the jet–jet scattering angle, dijet invariant mass and the fraction of the photon energy carried by the dijet system are presented for gluon- and quark-tagged jets. The data exhibit the behaviour expected from the underlying parton dynamics. A value of αs(MZ)αs(MZ) of View the MathML sourceαs(MZ)=0.1176±0.0009(stat.)−0.0026+0.0009(exp.)−0.0072+0.0091(th.) was extracted from the measurements of jet shapes in deep inelastic scattering.
SUBSTRUCTURE DEPENDENCE OF JET CROSS SECTIONS AT HERA AND DETERMINATION OF ALPHA(S) / S. Chekanov; M. Derrick; D. Krakauer; J.H. Loizides 1; S. Magill; B. Musgrave; J. Repond; R. Yoshida; M.C.K. Mattingly; P. Antonioli; G. Bari; M. Basile; L. Bellagamba; D. Boscherini; A. Bruni; G. Bruni; G. Cara Romeo; L. Cifarelli; F. Cindolo; A. Contin; M. Corradi; S. De Pasquale; P. Giusti; G. Iacobucci; A. Margotti; A. Montanari; R. Nania; F. Palmonari; A. Pesci; A. Pesci; L. Rinaldi; G. Sartorelli; A. Zichichi; G. Aghuzumtsyan; D. Bartsch; I. Brock; S. Goers; H. Hartmann; E. Hilger; P. Irrgang. - In: NUCLEAR PHYSICS. B. - ISSN 0550-3213. - STAMPA. - 700:(2004), pp. 3-50. [10.1016/j.nuclphysb.2004.08.049]
SUBSTRUCTURE DEPENDENCE OF JET CROSS SECTIONS AT HERA AND DETERMINATION OF ALPHA(S).
BASILE, MAURIZIO;CIFARELLI, LUISA;CONTIN, ANDREA;PALMONARI, FEDERICO;RINALDI, LORENZO;SARTORELLI, GABRIELLA;ZICHICHI, ANTONINO;
2004
Abstract
Jet substructure and differential cross sections for jets produced in the photoproduction and deep inelastic ep scattering regimes have been measured with the ZEUS detector at HERA using an integrated luminosity of 82.2 pb−182.2 pb−1. The substructure of jets has been studied in terms of the jet shape and subjet multiplicity for jets with transverse energies View the MathML sourceETjet>17 GeV. The data are well described by the QCD calculations. The jet shape and subjet multiplicity are used to tag gluon- and quark-initiated jets. Jet cross sections as functions of View the MathML sourceETjet, jet pseudorapidity, the jet–jet scattering angle, dijet invariant mass and the fraction of the photon energy carried by the dijet system are presented for gluon- and quark-tagged jets. The data exhibit the behaviour expected from the underlying parton dynamics. A value of αs(MZ)αs(MZ) of View the MathML sourceαs(MZ)=0.1176±0.0009(stat.)−0.0026+0.0009(exp.)−0.0072+0.0091(th.) was extracted from the measurements of jet shapes in deep inelastic scattering.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
