Massive color-octet bosons: bounds on effects in top-quark pair production

Article

Abstract

A critical survey of the existing direct and indirect constraints on massive spin-one color octets is presented. Since such new degrees of freedom appear in any extension of the color gauge group to a product of at least two SU(3) factors, we keep our discussion as independent as possible from the underlying theory. In the framework of scenarios that involve flavor non-universal couplings, we show that excessive flavor-changing neutral currents can be avoided by a suitable alignment in flavor space. Constraints from electroweak precision observables and direct production at hadron colliders still leave space for sizable new-physics effects in top-quark pair production, in particular a large forward-backward asymmetry. In this context, we derive a model-independent upper bound on the asymmetry that applies whenever top-antitop production receives the dominant corrections from s-channel exchange of a new single color-octet resonance.

Keywords

Hadronic Colliders Beyond Standard Model Gauge Symmetry Heavy Quark Physics 

References

  1. [1]
    L. Randall and R. Sundrum, A large mass hierarchy from a small extra dimension, Phys. Rev. Lett. 83 (1999) 3370 [hep-ph/9905221] [SPIRES].MATHADSMathSciNetCrossRefGoogle Scholar
  2. [2]
    C.T. Hill and E.H. Simmons, Strong dynamics and electroweak symmetry breaking, Phys. Rept. 381 (2003) 235 [Erratum ibid. 390 (2004) 553] [hep-ph/0203079] [SPIRES].ADSCrossRefGoogle Scholar
  3. [3]
    P.H. Frampton and S.L. Glashow, Chiral color: an alternative to the Standard Model, Phys. Lett. B 190 (1987) 157 [SPIRES].ADSGoogle Scholar
  4. [4]
    P.H. Frampton and S.L. Glashow, Unifiable chiral color with natural GIM mechanism, Phys. Rev. Lett. 58 (1987) 2168 [SPIRES].ADSCrossRefGoogle Scholar
  5. [5]
    J. Bagger, C. Schmidt and S. King, Axigluon production in hadronic collisions, Phys. Rev. D 37 (1988) 1188 [SPIRES].ADSGoogle Scholar
  6. [6]
    C.T. Hill, Topcolor: top quark condensation in a gauge extension of the Standard Model, Phys. Lett. B 266 (1991) 419 [SPIRES].ADSGoogle Scholar
  7. [7]
    C.T. Hill, Topcolor assisted technicolor, Phys. Lett. B 345 (1995) 483 [hep-ph/9411426] [SPIRES].ADSGoogle Scholar
  8. [8]
    C.T. Hill and S.J. Parke, Top production: sensitivity to new physics, Phys. Rev. D 49 (1994) 4454 [hep-ph/9312324] [SPIRES].ADSCrossRefGoogle Scholar
  9. [9]
    R.S. Chivukula, A.G. Cohen and E.H. Simmons, New strong interactions at the Tevatron?, Phys. Lett. B 380 (1996) 92 [hep-ph/9603311] [SPIRES].ADSGoogle Scholar
  10. [10]
    K. Agashe, A. Delgado, M.J. May and R. Sundrum, RS1, custodial isospin and precision tests, JHEP 08 (2003) 050 [hep-ph/0308036] [SPIRES].ADSCrossRefGoogle Scholar
  11. [11]
    K. Agashe, A. Belyaev, T. Krupovnickas, G. Perez and J. Virzi, LHC signals from warped extra dimensions, Phys. Rev. D 77 (2008) 015003 [hep-ph/0612015] [SPIRES].ADSGoogle Scholar
  12. [12]
    B. Lillie, L. Randall and L.-T. Wang, The bulk RS KK-gluon at the LHC, JHEP 09 (2007) 074 [hep-ph/0701166] [SPIRES].ADSCrossRefGoogle Scholar
  13. [13]
    CDF collaboration, E. Thomson et al., Combination of CDF top quark pair production cross section measurements with up to 4.6 fb1, conference note 9913, http://www-cdf.fnal.gov/physics/new/top/2009/xsection/ttbar_combined_46invfb/, Fermilab, Batavia U.S.A. (2009).
  14. [14]
    DØ collaboration, Combination and interpretation of \( t\bar{t} \) cross section measurements with thedetector, conference note 5907-CONF, http://www-d0.fnal.gov/Run2Physics/WWW/results/prelim/TOP/T79/, Fermilab, Batavia U.S.A. (2009).
  15. [15]
    CDF collaboration, T. Aaltonen et al., First measurement of the \( t\bar{t} \) differential cross section \( {{{d\sigma }} \left/ {{d{M_{t\bar{t}}}}} \right.} \) in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.96 \) TeV, Phys. Rev. Lett. 102 (2009) 222003 [arXiv:0903.2850] [SPIRES].ADSCrossRefGoogle Scholar
  16. [16]
    CDF collaboration, T. Aaltonen et al., Evidence for a mass dependent forward-backward asymmetry in top quark pair production, Phys. Rev. D 83 (2011) 112003 [arXiv:1101.0034] [SPIRES].ADSGoogle Scholar
  17. [17]
    T.A. Schwarz, Measurement of the front back asymmetry in top-antitop quark pairs produced in proton-antiproton collisions at center of mass energy = 1.96 TeV, FERMILAB-THESIS-2006-51, Fermilab, Batavia U.S.A. (2006) [UMI-32-38081] [SPIRES].
  18. [18]
    D0 collaboration, V.M. Abazov et al., First measurement of the forward-backward charge asymmetry in top quark pair production, Phys. Rev. Lett. 100 (2008) 142002 [arXiv:0712.0851] [SPIRES].ADSCrossRefGoogle Scholar
  19. [19]
    CDF collaboration, T. Aaltonen et al., Forward-backward asymmetry in top quark production in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.96 \) TeV, Phys. Rev. Lett. 101 (2008) 202001 [arXiv:0806.2472] [SPIRES].ADSCrossRefGoogle Scholar
  20. [20]
    DØ collaboration, Measurement of the forward-backward production asymmetry of t and \( \bar{t} \) quarks in \( p\bar{p} \to t\bar{t} \) events, conference note 6062-CONF, http://www-d0.fnal.gov/Run2Physics/WWW/results/prelim/TOP/T90/, Fermilab, Batavia U.S.A. (2010).
  21. [21]
    CDF collaboration, Measurement of the forward backward asymmetry in top pair production in the dilepton decay channel using 5.1 fb−1, CDF note 10398, http://www-cdf.fnal.gov/physics/new/top/2011/DilAfb/, Fermilab, Batavia U.S.A. (2011).
  22. [22]
    ALEPH collaboration, Precision electroweak measurements on the Z resonance, Phys. Rept. 427 (2006) 257 [hep-ex/0509008] [SPIRES].ADSGoogle Scholar
  23. [23]
    M.E. Peskin and T. Takeuchi, Estimation of oblique electroweak corrections, Phys. Rev. D 46 (1992) 381 [SPIRES].ADSGoogle Scholar
  24. [24]
    CMS collaboration, V. Khachatryan et al., Search for dijet resonances in 7 TeV pp collisions at CMS, Phys. Rev. Lett. 105 (2010) 211801 [Erratum ibid. 106 (2010) 029902] [arXiv:1010.0203] [SPIRES].ADSCrossRefGoogle Scholar
  25. [25]
    CMS collaboration, V. Khachatryan et al., Measurement of dijet angular distributions and search for quark compositeness in pp collisions at 7 TeV, Phys. Rev. Lett. 106 (2011) 201804 [arXiv:1102.2020] [SPIRES].ADSCrossRefGoogle Scholar
  26. [26]
    ATLAS collaboration, G. Aad et al., Search for new physics in dijet mass and angular distributions in pp collisions at \( \sqrt {s} = 7 \) TeV measured with the ATLAS detector, New J. Phys. 13 (2011) 053044 [arXiv:1103.3864] [SPIRES].ADSCrossRefGoogle Scholar
  27. [27]
    P.H. Frampton, J. Shu and K. Wang, Axigluon as possible explanation for \( p\bar{p} \to t\bar{t} \) forward-backward asymmetry, Phys. Lett. B 683 (2010) 294 [arXiv:0911.2955] [SPIRES].ADSGoogle Scholar
  28. [28]
    Q.-H. Cao, D. McKeen, J.L. Rosner, G. Shaughnessy and C.E.M. Wagner, Forward-backward asymmetry of top quark pair production, Phys. Rev. D 81 (2010) 114004 [arXiv:1003.3461] [SPIRES].ADSGoogle Scholar
  29. [29]
    R.S. Chivukula, E.H. Simmons and C.P. Yuan, Axigluons cannot explain the observed top quark forward-backward asymmetry, Phys. Rev. D 82 (2010) 094009 [arXiv:1007.0260] [SPIRES].ADSGoogle Scholar
  30. [30]
    T. Han, I. Lewis and Z. Liu, Colored resonant signals at the LHC: largest rate and simplest topology, JHEP 12 (2010) 085 [arXiv:1010.4309] [SPIRES].ADSCrossRefGoogle Scholar
  31. [31]
    Y. Bai, J.L. Hewett, J. Kaplan and T.G. Rizzo, LHC predictions from a Tevatron anomaly in the top quark forward-backward asymmetry, JHEP 03 (2011) 003 [arXiv:1101.5203] [SPIRES].ADSCrossRefGoogle Scholar
  32. [32]
    J.A. Aguilar-Saavedra and M. Pérez-Victoria, Probing the Tevatron \( t\bar{t} \) asymmetry at LHC, JHEP 05 (2011) 034 [arXiv:1103.2765] [SPIRES].ADSCrossRefGoogle Scholar
  33. [33]
    M.I. Gresham, I.-W. Kim and K.M. Zurek, On models of new physics for the Tevatron top A FB, Phys. Rev. D 83 (2011) 114027 [arXiv:1103.3501] [SPIRES].ADSGoogle Scholar
  34. [34]
    J.L. Hewett, J. Shelton, M. Spannowsky, T.M.P. Tait and M. Takeuchi, A FB t meets LHC, arXiv:1103.4618 [SPIRES].
  35. [35]
    R. Barcelo, A. Carmona, M. Masip and J. Santiago, Gluon excitations in \( t\bar{t} \) production at hadron colliders, Phys. Rev. D 84 (2011) 014024 [arXiv:1105.3333] [SPIRES].ADSGoogle Scholar
  36. [36]
    J.A. Aguilar-Saavedra and M. Pérez-Victoria, Asymmetries in \( t\bar{t} \) production: LHC versus Tevatron, arXiv:1105.4606 [SPIRES].
  37. [37]
    O. Antunano, J.H. Kühn and G. Rodrigo, Top quarks, axigluons and charge asymmetries at hadron colliders, Phys. Rev. D 77 (2008) 014003 [arXiv:0709.1652] [SPIRES].ADSGoogle Scholar
  38. [38]
    P. Ferrario and G. Rodrigo, Massive color-octet bosons and the charge asymmetries of top quarks at hadron colliders, Phys. Rev. D 78 (2008) 094018 [arXiv:0809.3354] [SPIRES].ADSGoogle Scholar
  39. [39]
    P. Ferrario and G. Rodrigo, Constraining heavy colored resonances from top-antitop quark events, Phys. Rev. D 80 (2009) 051701 [arXiv:0906.5541] [SPIRES].ADSGoogle Scholar
  40. [40]
    L3 collaboration, P. Achard et al., Search for heavy neutral and charged leptons in e + e annihilation at LEP, Phys. Lett. B 517 (2001) 75 [hep-ex/0107015] [SPIRES].ADSGoogle Scholar
  41. [41]
    CDF collaboration, A. Lister, Search for heavy top-like quarks t′ → Wq using lepton plus jets events in 1.96 TeV \( p\bar{p} \) collisions, arXiv:0810.3349 [SPIRES].
  42. [42]
    CDF collaboration, T. Aaltonen et al., Search for heavy bottom-like quarks decaying to an electron or muon and jets in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.96 \) TeV, Phys. Rev. Lett. 106 (2011) 141803 [arXiv:1101.5728] [SPIRES].ADSCrossRefGoogle Scholar
  43. [43]
    CMS collaboration, S. Chatrchyan et al., Search for a heavy bottom-like quark in pp collisions at \( \sqrt {s} = 7 \) TeV, Phys. Lett. B 701 (2011) 204 [arXiv:1102.4746] [SPIRES].ADSGoogle Scholar
  44. [44]
    G. Buchalla, G. Burdman, C.T. Hill and D. Kominis, GIM violation and new dynamics of the third generation, Phys. Rev. D 53 (1996) 5185 [hep-ph/9510376] [SPIRES].ADSGoogle Scholar
  45. [45]
    G. Burdman, K.D. Lane and T. Rador, Anti-B B mixing constrains topcolor-assisted technicolor, Phys. Lett. B 514 (2001) 41 [hep-ph/0012073] [SPIRES].ADSGoogle Scholar
  46. [46]
    A. Martin and K. Lane, CP violation and flavor mixing in technicolor models, Phys. Rev. D 71 (2005) 015011 [hep-ph/0404107] [SPIRES].ADSGoogle Scholar
  47. [47]
    A.J. Buras, S.Jäger and J. Urban, Master formulae forF = 2 NLO-QCD factors in the standard model and beyond, Nucl. Phys. B 605 (2001) 600 [hep-ph/0102316] [SPIRES].ADSCrossRefGoogle Scholar
  48. [48]
    J. Laiho, E. Lunghi and R.S. Van de Water, Lattice QCD inputs to the CKM unitarity triangle analysis, Phys. Rev. D 81 (2010) 034503 [arXiv:0910.2928] [SPIRES].ADSGoogle Scholar
  49. [49]
    V. Lubicz and C. Tarantino, Flavour physics and Lattice QCD: averages of lattice inputs for the Unitarity Triangle Analysis, Nuovo Cim. B 123 (2008) 674 [arXiv:0807.4605] [SPIRES].ADSGoogle Scholar
  50. [50]
    A.J. Buras, D. Guadagnoli and G. Isidori, On ϵ K beyond lowest order in the Operator Product Expansion, Phys. Lett. B 688 (2010) 309 [arXiv:1002.3612] [SPIRES].ADSGoogle Scholar
  51. [51]
    CKMfitter Group collaboration, J. Charles et al., CP violation and the CKM matrix: assessing the impact of the asymmetric B factories, Eur. Phys. J. C 41 (2005) 1 [hep-ph/0406184] [SPIRES].ADSCrossRefGoogle Scholar
  52. [52]
    J. Brod and M. Gorbahn, ϵ K at next-to-next-to-leading order: the charm-top-quark contribution, Phys. Rev. D 82 (2010) 094026 [arXiv:1007.0684] [SPIRES].ADSGoogle Scholar
  53. [53]
    Particle Data Group collaboration, K. Nakamura et al., Review of particle physics, J. Phys. G 37 (2010) 075021 [SPIRES].ADSGoogle Scholar
  54. [54]
    Heavy Flavor Averaging Group collaboration, D. Asner et al., Averages of b-hadron, c-hadron and tau-lepton properties, arXiv:1010.1589 [SPIRES].
  55. [55]
    C.T. Hill and X.-m. Zhang, \( Z \to b\bar{b} \) versus dynamical electroweak symmetry breaking involving the top quark, Phys. Rev. D 51 (1995) 3563 [hep-ph/9409315] [SPIRES].ADSGoogle Scholar
  56. [56]
    D0 collaboration, V.M. Abazov et al., Measurement of sin2 \( \theta_{\text{eff}}^{\text{lept}} \) and Z-light quark couplings using the forward-backward charge asymmetry in \( p\bar{p} \to {{Z} \left/ {{{\gamma^*}}} \right.} \to {e^{+} }{e^{-} } \) events with L = 5.0 fb−1 at \( \sqrt {s} = 1.96 \) TeV, Phys. Rev. D 84 (2011) 012007 [arXiv:1104.4590] [SPIRES].ADSGoogle Scholar
  57. [57]
    U. Baur, A. Juste, L.H. Orr and D. Rainwater, Probing electroweak top quark couplings at hadron colliders, Phys. Rev. D 71 (2005) 054013 [hep-ph/0412021] [SPIRES].ADSGoogle Scholar
  58. [58]
    U. Baur, A. Juste, D. Rainwater and L.H. Orr, Improved measurement of ttZ couplings at the CERN LHC, Phys. Rev. D 73 (2006) 034016 [hep-ph/0512262] [SPIRES].ADSGoogle Scholar
  59. [59]
    E.L. Berger, Q.-H. Cao and I. Low, Modelindependent constraintsamongthe Wtb, Zbb and Ztt couplings, Phys. Rev. D 80 (2009) 074020 [arXiv:0907.2191] [SPIRES].ADSGoogle Scholar
  60. [60]
    J.H. Field, Indications for an anomalous righthanded coupling of the b-quark from a model independent analysis of LEP and SLD data on Z decays, Mod. Phys. Lett. A 13 (1998) 1937 [hep-ph/9801355] [SPIRES].ADSGoogle Scholar
  61. [61]
    A.B. Arbuzov et al., ZFITTER: a semi-analytical program for fermion pair production in e + e annihilation, from version 6.21 to version 6.42, Comput. Phys. Commun. 174 (2006) 728 [hep-ph/0507146] [SPIRES].ADSCrossRefGoogle Scholar
  62. [62]
    CDF and D0 collaboration and others, Combination of CDF and DØ results on the mass of the top quark, arXiv:1007.3178 [SPIRES].
  63. [63]
    G. Burdman, R.S. Chivukula and N.J. Evans, Precision bounds on flavor gauge bosons, Phys. Rev. D 61 (2000) 035009 [hep-ph/9906292] [SPIRES].ADSGoogle Scholar
  64. [64]
    H.-J. He, N. Polonsky and S.-F. Su, Extra families, Higgs spectrum and oblique corrections, Phys. Rev. D 64 (2001) 053004 [hep-ph/0102144] [SPIRES].ADSGoogle Scholar
  65. [65]
    A. Bridgeman, Measurement of the \( t\bar{t} \) differential cross section, \( {{{d\sigma }} \left/ {{d{M_{t\bar{t}}}}} \right.} \) , in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.96 \) TeV, FERMILAB-THESIS-2008-50, Fermilab, Batavia U.S.A. [SPIRES].
  66. [66]
    CDF collaboration, T. Aaltonen et al., Search for new particles decaying into dijets in proton-antiproton collisions at \( \sqrt {s} = 1.96 \) TeV, Phys. Rev. D 79 (2009) 112002 [arXiv:0812.4036] [SPIRES].ADSGoogle Scholar
  67. [67]
    ATLAS collaboration, G. Aad et al., Search for new particles in two-jet final states in 7 TeV proton-proton collisions with the ATLAS detector at the LHC, Phys. Rev. Lett. 105 (2010) 161801 [arXiv:1008.2461] [SPIRES].ADSCrossRefGoogle Scholar
  68. [68]
    D0 collaboration, V.M. Abazov et al., Measurement of dijet angular distributions at \( \sqrt {s} = 1.96 \) TeV and searches for quark compositeness and extra spatial dimensions, Phys. Rev. Lett. 103 (2009) 191803 [arXiv:0906.4819] [SPIRES].ADSCrossRefGoogle Scholar
  69. [69]
    ATLAS collaboration, G. Aad et al., Search for quark contact interactions in dijet angular distributions in pp collisions at \( \sqrt {s} = 7 \) TeV measured with the ATLAS detector, Phys. Lett. B 694 (2011) 327 [arXiv:1009.5069] [SPIRES].ADSGoogle Scholar
  70. [70]
    L. Randall and M.D. Schwartz, Quantum field theory and unification in AdS 5, JHEP 11 (2001) 003 [hep-th/0108114] [SPIRES].ADSMathSciNetCrossRefGoogle Scholar
  71. [71]
    M. Bauer, F. Goertz, U. Haisch, T. Pfoh and S. Westhoff, Top-quark forward-backward asymmetry in Randall-Sundrum models beyond the leading order, JHEP 11 (2010) 039 [arXiv:1008.0742] [SPIRES].ADSCrossRefGoogle Scholar
  72. [72]
    J. Campbell and R.K. Ellis, MCFM — a Monte Carlo for FeMtobarn processes at hadron colliders homepage, http://mcfm.fnal.gov, Fermilab, Batavia U.S.A. (2011).
  73. [73]
    P. Nason, S. Dawson and R.K. Ellis, The total cross-section for the production of heavy quarks in hadronic collisions, Nucl. Phys. B 303 (1988) 607 [SPIRES].ADSCrossRefGoogle Scholar
  74. [74]
    A.D. Martin, W.J. Stirling, R.S. Thorne and G. Watt, Parton distributions for the LHC, Eur. Phys. J. C 63 (2009) 189 [arXiv:0901.0002] [SPIRES].ADSCrossRefGoogle Scholar
  75. [75]
    R.K. Ellis, W.J. Stirling and B.R. Webber, QCD and collider physics, Camb. Monogr. Part. Phys. Nucl. Phys. Cosmol. 8 (1996) 1 [SPIRES].Google Scholar
  76. [76]
    E. Eichten, K.D. Lane and M.E. Peskin, New tests for quark and lepton substructure, Phys. Rev. Lett. 50 (1983) 811 [SPIRES].ADSCrossRefGoogle Scholar
  77. [77]
    K.D. Lane, Electroweak and flavor dynamics at hadron colliders, hep-ph/9605257 [SPIRES].
  78. [78]
    J. Gao, C.S. Li, J. Wang, H.X. Zhu and C.P. Yuan, Next-to-leading QCD effect to the quark compositeness search at the LHC, Phys. Rev. Lett. 106 (2011) 142001 [arXiv:1101.4611] [SPIRES].ADSCrossRefGoogle Scholar
  79. [79]
    UA1 collaboration, C. Albajar et al., Two jet mass distributions at the CERN proton-anti-proton collider, Phys. Lett. B 209 (1988) 127 [SPIRES].ADSGoogle Scholar
  80. [80]
    CDF collaboration, F. Abe et al., Search for quark compositeness, axigluons and heavy particles using the dijet invariant mass spectrum observed in \( p\bar{p} \) collisions, Phys. Rev. Lett. 71 (1993) 2542 [SPIRES].ADSCrossRefGoogle Scholar
  81. [81]
    C.D. Carone and H. Murayama, Possible light U(1) gauge boson coupled to baryon number, Phys. Rev. Lett. 74 (1995) 3122 [hep-ph/9411256] [SPIRES].ADSCrossRefGoogle Scholar
  82. [82]
    B. Holdom, New third family flavor physics: vertex corrections, Phys. Lett. B 351 (1995) 279 [hep-ph/9502273] [SPIRES].ADSGoogle Scholar
  83. [83]
    A.I. Davydychev and J.B. Tausk, Two loop selfenergy diagrams with different masses and the momentum expansion, Nucl. Phys. B 397 (1993) 123 [SPIRES].ADSCrossRefGoogle Scholar

Copyright information

© SISSA, Trieste, Italy 2011

Authors and Affiliations

  1. 1.Institut für Physik (THEP)Johannes Gutenberg-UniversitätMainzGermany
  2. 2.Helmholtz-Institut MainzJohannes Gutenberg-UniversitätMainzGermany
  3. 3.Rudolf Peierls Centre for Theoretical PhysicsUniversity of OxfordOxfordU.K.

Personalised recommendations