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Title: Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV

Abstract

A study of event shape observables in proton-antiproton collisions at {radical}s = 1.96 TeV is presented. The data for this analysis were recorded by the CDF II detector at the Tevatron collider. The variables studied are the transverse thrust and thrust minor, both defined in the plane perpendicular to the beam direction. The observables are measured using energies from unclustered calorimeter cells. In addition to studies of the differential distributions, we present the dependence of event shape mean values on the leading jet transverse energy. Data are compared with pythia Tune A and to resummed parton level predictions that were matched to fixed order results at NLO accuracy (NLO+NLL). Predictions from pythia Tune A agree fairly well with the data. However, the underlying event contributes significantly to these observables, making it difficult to make direct comparisons to the NLO+NLL predictions, which do not account for the underlying event. To overcome this difficulty, we introduce a new observable, a weighted difference of the mean values of the thrust and thrust minor, which is less sensitive to the underlying event, allowing for a comparison with NLO+NLL. Both pythia Tune A and the NLO+NLL calculations agree well within the 20% theoretical uncertainty withmore » the data for this observable, indicating that perturbative QCD successfully describes shapes of the hadronic final states.« less

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1010696
Report Number(s):
FERMILAB-PUB-11-157-E
arXiv eprint number arXiv:1103.5143; TRN: US1101964
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article
Journal Name:
Submitted to Phys.Rev.D
Additional Journal Information:
Journal Name: Submitted to Phys.Rev.D
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ACCURACY; CALORIMETERS; FERMILAB COLLIDER DETECTOR; FERMILAB TEVATRON; QUANTUM CHROMODYNAMICS; SHAPE; TRANSVERSE ENERGY; Experiment-HEP

Citation Formats

Aaltonen, T, Aaltonen, T, /Helsinki Inst. of Phys., Alvarez Gonzalez, B, /Oviedo U. /Cantabria Inst. of Phys., Amerio, S, /INFN, Padua, Amidei, D, /Michigan U., Anastassov, A, /Northwestern U., Annovi, A, /Frascati, Antos, J, /Comenius U., Apollinari, G, /Fermilab, Appel, J A, /Fermilab, Apresyan, A, and /Purdue U. /Waseda U. /Dubna, JINR. Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV. United States: N. p., 2011. Web.
Aaltonen, T, Aaltonen, T, /Helsinki Inst. of Phys., Alvarez Gonzalez, B, /Oviedo U. /Cantabria Inst. of Phys., Amerio, S, /INFN, Padua, Amidei, D, /Michigan U., Anastassov, A, /Northwestern U., Annovi, A, /Frascati, Antos, J, /Comenius U., Apollinari, G, /Fermilab, Appel, J A, /Fermilab, Apresyan, A, & /Purdue U. /Waseda U. /Dubna, JINR. Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV. United States.
Aaltonen, T, Aaltonen, T, /Helsinki Inst. of Phys., Alvarez Gonzalez, B, /Oviedo U. /Cantabria Inst. of Phys., Amerio, S, /INFN, Padua, Amidei, D, /Michigan U., Anastassov, A, /Northwestern U., Annovi, A, /Frascati, Antos, J, /Comenius U., Apollinari, G, /Fermilab, Appel, J A, /Fermilab, Apresyan, A, and /Purdue U. /Waseda U. /Dubna, JINR. Tue . "Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV". United States. https://www.osti.gov/servlets/purl/1010696.
@article{osti_1010696,
title = {Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV},
author = {Aaltonen, T and Aaltonen, T and /Helsinki Inst. of Phys. and Alvarez Gonzalez, B and /Oviedo U. /Cantabria Inst. of Phys. and Amerio, S and /INFN, Padua and Amidei, D and /Michigan U. and Anastassov, A and /Northwestern U. and Annovi, A and /Frascati and Antos, J and /Comenius U. and Apollinari, G and /Fermilab and Appel, J A and /Fermilab and Apresyan, A and /Purdue U. /Waseda U. /Dubna, JINR},
abstractNote = {A study of event shape observables in proton-antiproton collisions at {radical}s = 1.96 TeV is presented. The data for this analysis were recorded by the CDF II detector at the Tevatron collider. The variables studied are the transverse thrust and thrust minor, both defined in the plane perpendicular to the beam direction. The observables are measured using energies from unclustered calorimeter cells. In addition to studies of the differential distributions, we present the dependence of event shape mean values on the leading jet transverse energy. Data are compared with pythia Tune A and to resummed parton level predictions that were matched to fixed order results at NLO accuracy (NLO+NLL). Predictions from pythia Tune A agree fairly well with the data. However, the underlying event contributes significantly to these observables, making it difficult to make direct comparisons to the NLO+NLL predictions, which do not account for the underlying event. To overcome this difficulty, we introduce a new observable, a weighted difference of the mean values of the thrust and thrust minor, which is less sensitive to the underlying event, allowing for a comparison with NLO+NLL. Both pythia Tune A and the NLO+NLL calculations agree well within the 20% theoretical uncertainty with the data for this observable, indicating that perturbative QCD successfully describes shapes of the hadronic final states.},
doi = {},
journal = {Submitted to Phys.Rev.D},
number = ,
volume = ,
place = {United States},
year = {2011},
month = {3}
}