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Title: Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production

Abstract

We present a new measurement of the inclusive forward-backward t{bar t} production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t{bar t} rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and {bar t}. In the t{bar t} rest frame, the asymmetry is observed to increase with the t{bar t} rapidity difference, {Delta}y, and with the invariant mass M{sub t{bar t}} of the t{bar t} system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large {Delta}y and M{sub t{bar t}}. For M{sub t{bar t}} {ge} 450 GeV/c{sup 2}, the parton-level asymmetry in the t{bar t} rest frame is A{sup t{bar t}} = 0.475 {+-} 0.114 compared to a next-to-leading order QCD prediction of 0.088 {+-} 0.013.

Authors:
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Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1001375
Report Number(s):
FERMILAB-PUB-10-525-E
Journal ID: ISSN 1550--7998; arXiv eprint number arXiv:1101.0034; TRN: US1100344
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article
Journal Name:
Submitted to Phys.Rev.D
Additional Journal Information:
Journal Volume: 83; Journal Issue: 11; Journal ID: ISSN 1550--7998
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; FERMILAB COLLIDER DETECTOR; FERMILAB TEVATRON; FORECASTING; LUMINOSITY; PAIR PRODUCTION; PARTICLE RAPIDITY; PRODUCTION; QUANTUM CHROMODYNAMICS; T QUARKS; Experiment-HEP

Citation Formats

Aaltonen, T., /Helsinki Inst. of Phys., Alvarez Gonzalez, B., /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., Arisawa, T., and /Waseda U. /Dubna, JINR. Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production. United States: N. p., 2011. Web. doi:10.1103/PhysRevD.83.112003.
Aaltonen, T., /Helsinki Inst. of Phys., Alvarez Gonzalez, B., /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., Arisawa, T., & /Waseda U. /Dubna, JINR. Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production. United States. doi:10.1103/PhysRevD.83.112003.
Aaltonen, T., /Helsinki Inst. of Phys., Alvarez Gonzalez, B., /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., Arisawa, T., and /Waseda U. /Dubna, JINR. Sat . "Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production". United States. doi:10.1103/PhysRevD.83.112003. https://www.osti.gov/servlets/purl/1001375.
@article{osti_1001375,
title = {Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production},
author = {Aaltonen, T. and /Helsinki Inst. of Phys. and Alvarez Gonzalez, B. and /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. and Arisawa, T. and /Waseda U. /Dubna, JINR},
abstractNote = {We present a new measurement of the inclusive forward-backward t{bar t} production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t{bar t} rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and {bar t}. In the t{bar t} rest frame, the asymmetry is observed to increase with the t{bar t} rapidity difference, {Delta}y, and with the invariant mass M{sub t{bar t}} of the t{bar t} system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large {Delta}y and M{sub t{bar t}}. For M{sub t{bar t}} {ge} 450 GeV/c{sup 2}, the parton-level asymmetry in the t{bar t} rest frame is A{sup t{bar t}} = 0.475 {+-} 0.114 compared to a next-to-leading order QCD prediction of 0.088 {+-} 0.013.},
doi = {10.1103/PhysRevD.83.112003},
journal = {Submitted to Phys.Rev.D},
issn = {1550--7998},
number = 11,
volume = 83,
place = {United States},
year = {2011},
month = {1}
}