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Title: Forward-backward asymmetry of top quark pair production

Abstract

We adopt a Markov chain Monte Carlo method to examine various new physics models which can generate the forward-backward asymmetry in top quark pair production observed at the Tevatron by the CDF Collaboration. We study the following new physics models: (1) exotic gluon G{sup '}, (2) extra Z{sup '} boson with flavor-conserving interaction, (3) extra Z{sup '} with flavor-violating u-t-Z{sup '} interaction, (4) extra W{sup '} with flavor-violating d-t-W{sup '} interaction, and (5) extra scalars S and S{sup {+-}}with flavor-violating u-t-S and d-t-S{sup {+-}}interactions. After combining the forward-backward asymmetry with the measurement of the top pair production cross section and the tt invariant mass distribution at the Tevatron, we find that an axial vector exotic gluon G{sup '} of mass about 1 TeV or 2 TeV or a W{sup '} of mass about 2TeV offer an improvement over the standard model. The other models considered do not fit the data significantly better than the standard model. We also emphasize a few points that have been long ignored in the literature for new physics searches: (1) heavy resonance width effects, (2) renormalization scale dependence, and (3) next-to-leading order corrections to the tt invariant mass spectrum. We argue that these three effectsmore » are crucial to test or exclude new physics effects in the top quark pair asymmetry.« less

Authors:
 [1];  [2]; ;  [3];  [1];  [2];  [1];  [2];  [2]
  1. HEP Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
  2. (United States)
  3. Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)
Publication Date:
OSTI Identifier:
21407950
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 81; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevD.81.114004; (c) 2010 The American Physical Society; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; CORRECTIONS; CROSS SECTIONS; FERMILAB COLLIDER DETECTOR; FERMILAB TEVATRON; FLAVOR MODEL; GLUONS; MARKOV PROCESS; MASS; MASS DISTRIBUTION; MASS SPECTRA; MONTE CARLO METHOD; PAIR PRODUCTION; RENORMALIZATION; RESONANCE; STANDARD MODEL; T QUARKS; TEV RANGE 01-10; ACCELERATORS; BOSONS; CALCULATION METHODS; COMPOSITE MODELS; CYCLIC ACCELERATORS; DISTRIBUTION; ELEMENTARY PARTICLES; ENERGY RANGE; FERMIONS; FIELD THEORIES; GRAND UNIFIED THEORY; INTERACTIONS; MATHEMATICAL MODELS; MEASURING INSTRUMENTS; PARTICLE MODELS; PARTICLE PRODUCTION; POSTULATED PARTICLES; QUANTUM FIELD THEORY; QUARK MODEL; QUARKS; RADIATION DETECTORS; SPATIAL DISTRIBUTION; SPECTRA; STOCHASTIC PROCESSES; SYNCHROTRONS; TEV RANGE; TOP PARTICLES; UNIFIED GAUGE MODELS

Citation Formats

Cao Qinghong, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, McKeen, David, Rosner, Jonathan L., Shaughnessy, Gabe, Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, Wagner, Carlos E. M., Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637. Forward-backward asymmetry of top quark pair production. United States: N. p., 2010. Web. doi:10.1103/PHYSREVD.81.114004.
Cao Qinghong, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, McKeen, David, Rosner, Jonathan L., Shaughnessy, Gabe, Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, Wagner, Carlos E. M., Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, & Kavli Institute for Cosmological Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637. Forward-backward asymmetry of top quark pair production. United States. doi:10.1103/PHYSREVD.81.114004.
Cao Qinghong, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, McKeen, David, Rosner, Jonathan L., Shaughnessy, Gabe, Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, Wagner, Carlos E. M., Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637. Tue . "Forward-backward asymmetry of top quark pair production". United States. doi:10.1103/PHYSREVD.81.114004.
@article{osti_21407950,
title = {Forward-backward asymmetry of top quark pair production},
author = {Cao Qinghong and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 and McKeen, David and Rosner, Jonathan L. and Shaughnessy, Gabe and Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 and Wagner, Carlos E. M. and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 and Kavli Institute for Cosmological Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637},
abstractNote = {We adopt a Markov chain Monte Carlo method to examine various new physics models which can generate the forward-backward asymmetry in top quark pair production observed at the Tevatron by the CDF Collaboration. We study the following new physics models: (1) exotic gluon G{sup '}, (2) extra Z{sup '} boson with flavor-conserving interaction, (3) extra Z{sup '} with flavor-violating u-t-Z{sup '} interaction, (4) extra W{sup '} with flavor-violating d-t-W{sup '} interaction, and (5) extra scalars S and S{sup {+-}}with flavor-violating u-t-S and d-t-S{sup {+-}}interactions. After combining the forward-backward asymmetry with the measurement of the top pair production cross section and the tt invariant mass distribution at the Tevatron, we find that an axial vector exotic gluon G{sup '} of mass about 1 TeV or 2 TeV or a W{sup '} of mass about 2TeV offer an improvement over the standard model. The other models considered do not fit the data significantly better than the standard model. We also emphasize a few points that have been long ignored in the literature for new physics searches: (1) heavy resonance width effects, (2) renormalization scale dependence, and (3) next-to-leading order corrections to the tt invariant mass spectrum. We argue that these three effects are crucial to test or exclude new physics effects in the top quark pair asymmetry.},
doi = {10.1103/PHYSREVD.81.114004},
journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 11,
volume = 81,
place = {United States},
year = {2010},
month = {6}
}