IFAE-Barcelona
Authors
Regis Lefevre (regis@fnal.gov)
Mario Martinez
(mmp@fnal.gov)
Olga Norniella
(norniell@fnal.gov)
P.0. Box 500,
M.S. 318
Batavia, Illinois
60510
USA
- We
present preliminary results on inclusive jet production using the longitudinally
invariant Kt algorithm (Ellis-Soper inclusive mode) for jets in the region
0.1 < |Y| < 0.7 and P_T > 54 GeV/c. Results are based on 385 pb-1
of CDF II data. Measurements are corrected to the hadron level and compared
to pQCD NLO calculations
as implemented in JETRAD including parton-to-hadron corrections.
- Highest Pt jet event lego plot &
phi-view
- Illustration of the effect of different jet algorithms in one event lego plot
==============================================================================
The plots show the differential inclusive jet production cross sections as a function of P_T^JET measured for central jets (0.1 < | Y^JET | < 0.7) at CDF Run II using the K_T algorithm with a D parameter of 0.5, 0.7 and 1.0. The measured cross sections are fully unfolded to the hadron level.
The NLO predictions are corrected to the hadron level: the "parton-to-hadron correction" plots show the correction factor (C_HAD) that take into account both underlying event and hadronization effects. The nominal parton to hadron level correction is extracted from PYTHIA Tune A, HERWIG is used to set the uncertainty associated to the Monte Carlo modeling of the underlying event and hadronization processes.
On the "Cross Section" and "Ratio" plots, the error bars represent the statistical errors on the measurements while the yellow bands represent the systematic uncertainties on the measurements which are dominated by the effect of the jet energy scale uncertainty. There is a 5.8% systematic uncertainty on the integrated luminosity that is not included here.
The nominal NLO predictions are obtained from JETRAD using CTEQ6.1M PDF and setting the renormalization and factorization scales to maximum P_T^JET / 2. On the "Ratio" plots, the full red lines show the PDF uncertainties which are dominated by the uncertainties on the gluon contribution at high x, the dotted-dashed purple line shows the effect of changing the renormalization and factorization scales to maximum P_T^JET and the dashed blue line shows the effect of using MRST2004 PDF instead of CTEQ6.1M PDF.
The presented P_T^JET range goes from 54 GeV/c to 700 GeV/c. The measurements extend over around 8 orders of magnitude. They are in very good agreement with the NLO over all the P_T^JET range. In the last bin (527 to 700 GeV/c), we observe before unfolding: 7 jets for D = 0.5, 7 jets for D = 0.7, 8 jets for D = 1.0.
Blessed Plots
| KT parameter | Cross Section | Ratio | parton-hadron correction |
| D=0.5 | eps & gif | eps & gif | eps & gif |
| D=0.7 | eps & gif | eps & gif | eps & gif |
| D=1.0 | eps & gif | eps & gif | eps & gif |
Event Displays