Journal of High Energy Physics

, 2012:130 | Cite as

Single-top t-channel hadroproduction in the four-flavour scheme with POWHEG and aMC@NLO

Open Access
Article

Abstract

We present results for the QCD next-to-leading order (NLO) calculation of single-top t-channel production in the 4-flavour scheme, interfaced to Parton Shower (PS) Monte Carlo programs according to the POWHEG and MC@NLO methods. Comparisons between the two methods, as well as with the corresponding process in the 5-flavour scheme are presented. For the first time results for typical kinematic distributions of the spectator-b jet are presented in an NLO + PS approach.

Keywords

Monte Carlo Simulations NLO Computations 

References

  1. [1]
    W. Bernreuther, Top quark physics at the LHC, J. Phys. G 35 (2008) 083001 [arXiv:0805.1333] [INSPIRE].ADSCrossRefGoogle Scholar
  2. [2]
    J. Alwall et al., Is V tb = 1?, Eur. Phys. J. C 49 (2007) 791 [hep-ph/0607115] [INSPIRE].ADSCrossRefGoogle Scholar
  3. [3]
    H. Lacker et al., Model-independent extraction of |V tq| matrix elements from top-quark measurements at hadron colliders, Eur. Phys. J. C 72 (2012) 2048 [arXiv:1202.4694] [INSPIRE].ADSCrossRefGoogle Scholar
  4. [4]
    T.M.P. Tait and C.-P. Yuan, Single top quark production as a window to physics beyond the standard model, Phys. Rev. D 63 (2000) 014018 [hep-ph/0007298] [INSPIRE].ADSGoogle Scholar
  5. [5]
    Q.-H. Cao, J. Wudka and C.-P. Yuan, Search for new physics via single top production at the LHC, Phys. Lett. B 658 (2007) 50 [arXiv:0704.2809] [INSPIRE].ADSCrossRefGoogle Scholar
  6. [6]
    S.S.D. Willenbrock and D.A. Dicus, Production of heavy quarks from W gluon fusion, Phys. Rev. D 34 (1986) 155 [INSPIRE].ADSGoogle Scholar
  7. [7]
    B.W. Harris, E. Laenen, L. Phaf, Z. Sullivan and S. Weinzierl, The fully differential single top quark cross-section in next to leading order QCD, Phys. Rev. D 66 (2002) 054024 [hep-ph/0207055] [INSPIRE].ADSGoogle Scholar
  8. [8]
    J.M. Campbell, R.K. Ellis and F. Tramontano, Single top production and decay at next-to-leading order, Phys. Rev. D 70 (2004) 094012 [hep-ph/0408158] [INSPIRE].ADSGoogle Scholar
  9. [9]
    Q.-H. Cao, R. Schwienhorst, J.A. Benitez, R. Brock and C.-P. Yuan, Next-to-leading order corrections to single top quark production and decay at the Tevatron: 2. t-channel process, Phys. Rev. D 72 (2005) 094027 [hep-ph/0504230] [INSPIRE].ADSGoogle Scholar
  10. [10]
    J. Wang, C.S. Li, H.X. Zhu and J.J. Zhang, Factorization and resummation of t-channel single top quark production, arXiv:1010.4509 [INSPIRE].
  11. [11]
    N. Kidonakis, Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production, Phys. Rev. D 83 (2011) 091503 [arXiv:1103.2792] [INSPIRE].ADSGoogle Scholar
  12. [12]
    P. Falgari, P. Mellor and A. Signer, Production-decay interferences at NLO in QCD for t-channel single-top production, Phys. Rev. D 82 (2010) 054028 [arXiv:1007.0893] [INSPIRE].ADSGoogle Scholar
  13. [13]
    P. Falgari, F. Giannuzzi, P. Mellor and A. Signer, Off-shell effects for t-channel and s-channel single-top production at NLO in QCD, Phys. Rev. D 83 (2011) 094013 [arXiv:1102.5267] [INSPIRE].ADSGoogle Scholar
  14. [14]
    M. Beccaria et al., A complete one-loop calculation of electroweak supersymmetric effects in t-channel single top production at CERN LHC, Phys. Rev. D 77 (2008) 113018 [arXiv:0802.1994] [INSPIRE].ADSGoogle Scholar
  15. [15]
    J.M. Campbell, R. Frederix, F. Maltoni and F. Tramontano, Next-to-leading-order predictions for t-channel single-top production at hadron colliders, Phys. Rev. Lett. 102 (2009) 182003 [arXiv:0903.0005] [INSPIRE].ADSCrossRefGoogle Scholar
  16. [16]
    J.M. Campbell, R. Frederix, F. Maltoni and F. Tramontano, NLO predictions for t-channel production of single top and fourth generation quarks at hadron colliders, JHEP 10 (2009) 042 [arXiv:0907.3933] [INSPIRE].ADSCrossRefGoogle Scholar
  17. [17]
    J.M. Campbell and R.K. Ellis, Top-quark processes at NLO in production and decay, arXiv:1204.1513 [INSPIRE].
  18. [18]
    CDF collaboration, T. Aaltonen et al., Observation of single top quark production and measurement of |V tb| with CDF, Phys. Rev. D 82 (2010) 112005 [arXiv:1004.1181] [INSPIRE].ADSGoogle Scholar
  19. [19]
    D0 collaboration, V.M. Abazov et al., Observation of single top quark production, Phys. Rev. Lett. 103 (2009) 092001 [arXiv:0903.0850] [INSPIRE].ADSCrossRefGoogle Scholar
  20. [20]
    D0 collaboration, V.M. Abazov et al., Measurement of the t-channel single top quark production cross section, Phys. Lett. B 682 (2010) 363 [arXiv:0907.4259] [INSPIRE].ADSCrossRefGoogle Scholar
  21. [21]
    Tevatron Electroweak Working Group, CDF and D0 collaborations, Combination of CDF and D0 measurements of the single top production cross section, arXiv:0908.2171 [INSPIRE].
  22. [22]
    CMS collaboration, S. Chatrchyan et al., Measurement of the t-channel single top quark production cross section in pp collisions at \( \sqrt {s} = {7} \) TeV, Phys. Rev. Lett. 107 (2011) 091802 [arXiv:1106.3052] [INSPIRE].ADSCrossRefGoogle Scholar
  23. [23]
    ATLAS collaboration, G. Aad et al., Search for FCNC single top-quark production at \( \sqrt {s} = {7} \) TeV with the ATLAS detector, Phys. Lett. B 712 (2012) 351 [arXiv:1203.0529] [INSPIRE].ADSCrossRefGoogle Scholar
  24. [24]
    ATLAS collaboration, G. Aad et al., Measurement of the t-channel single top-quark production cross section in pp collisions at \( \sqrt {s} = {7} \) TeV with the ATLAS detector, arXiv:1205.3130 [INSPIRE].
  25. [25]
    ATLAS collaboration, G. Aad et al., Evidence for the associated production of a W boson and a top quark in ATLAS at \( \sqrt {s} = {7} \) TeV, Phys. Lett. B 716 (2012) 142 [arXiv:1205.5764] [INSPIRE].ADSCrossRefGoogle Scholar
  26. [26]
    S. Frixione and B.R. Webber, Matching NLO QCD computations and parton shower simulations, JHEP 06 (2002) 029 [hep-ph/0204244] [INSPIRE].ADSCrossRefGoogle Scholar
  27. [27]
    P. Nason, A new method for combining NLO QCD with shower Monte Carlo algorithms, JHEP 11 (2004) 040 [hep-ph/0409146] [INSPIRE].ADSCrossRefGoogle Scholar
  28. [28]
    S. Alioli, P. Nason, C. Oleari and E. Re, A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX, JHEP 06 (2010) 043 [arXiv:1002.2581] [INSPIRE].ADSCrossRefGoogle Scholar
  29. [29]
    R. Frederix et al., Scalar and pseudoscalar Higgs production in association with a top-antitop pair, Phys. Lett. B 701 (2011) 427 [arXiv:1104.5613] [INSPIRE].ADSCrossRefGoogle Scholar
  30. [30]
    S. Hoche, F. Krauss, M. Schonherr and F. Siegert, Automating the POWHEG method in Sherpa, JHEP 04 (2011) 024 [arXiv:1008.5399] [INSPIRE].ADSCrossRefGoogle Scholar
  31. [31]
    S. Hoeche, F. Krauss, M. Schonherr and F. Siegert, A critical appraisal of NLO+PS matching methods, arXiv:1111.1220 [INSPIRE].
  32. [32]
    S. Platzer and S. Gieseke, Dipole showers and automated NLO matching in HERWIG++, arXiv:1109.6256 [INSPIRE].
  33. [33]
    S. Frixione, E. Laenen, P. Motylinski and B.R. Webber, Single-top production in MC@NLO, JHEP 03 (2006) 092 [hep-ph/0512250] [INSPIRE].ADSCrossRefGoogle Scholar
  34. [34]
    S. Frixione, E. Laenen, P. Motylinski, B.R. Webber and C.D. White, Single-top hadroproduction in association with a W boson, JHEP 07 (2008) 029 [arXiv:0805.3067] [INSPIRE].ADSCrossRefGoogle Scholar
  35. [35]
    S. Alioli, P. Nason, C. Oleari and E. Re, NLO single-top production matched with shower in POWHEG: s- and t-channel contributions, JHEP 09 (2009) 111 [Erratum ibid. 02 (2010) 011] [arXiv:0907.4076] [INSPIRE].
  36. [36]
    E. Re, Single-top Wt-channel production matched with parton showers using the POWHEG method, Eur. Phys. J. C 71 (2011) 1547 [arXiv:1009.2450] [INSPIRE].ADSGoogle Scholar
  37. [37]
    F. Maltoni, G. Ridolfi and M. Ubiali, b-initiated processes at the LHC: a reappraisal, JHEP 07 (2012) 022 [arXiv:1203.6393] [INSPIRE].ADSCrossRefGoogle Scholar
  38. [38]
    R. Frederix, S. Frixione, F. Maltoni and T. Stelzer, Automation of next-to-leading order computations in QCD: the FKS subtraction, JHEP 10 (2009) 003 [arXiv:0908.4272] [INSPIRE].ADSCrossRefGoogle Scholar
  39. [39]
    S. Frixione, Z. Kunszt and A. Signer, Three jet cross-sections to next-to-leading order, Nucl. Phys. B 467 (1996) 399 [hep-ph/9512328] [INSPIRE].ADSCrossRefGoogle Scholar
  40. [40]
    V. Hirschi et al., Automation of one-loop QCD corrections, JHEP 05 (2011) 044 [arXiv:1103.0621] [INSPIRE].ADSCrossRefGoogle Scholar
  41. [41]
    S. Frixione, P. Nason and C. Oleari, Matching NLO QCD computations with Parton Shower simulations: the POWHEG method, JHEP 11 (2007) 070 [arXiv:0709.2092] [INSPIRE].ADSCrossRefGoogle Scholar
  42. [42]
    E. Byckling and K. Kajantie, N-particle phase space in terms of invariant momentum transfers, Nucl. Phys. B 9 (1969) 568 [INSPIRE].ADSCrossRefGoogle Scholar
  43. [43]
    J. Alwall et al., MadGraph/MadEvent v4: the new web generation, JHEP 09 (2007) 028 [arXiv:0706.2334] [INSPIRE].ADSCrossRefGoogle Scholar
  44. [44]
    R. Mertig, M. Böhm and A. Denner, FEYN CALC: computer algebraic calculation of Feynman amplitudes, Comput. Phys. Commun. 64 (1991) 345 [INSPIRE].ADSCrossRefGoogle Scholar
  45. [45]
    S. Catani and M. Seymour, A general algorithm for calculating jet cross-sections in NLO QCD, Nucl. Phys. B 485 (1997) 291 [Erratum ibid. B 510 (1998) 503] [hep-ph/9605323] [INSPIRE].
  46. [46]
    A. Martin, W. Stirling, R. Thorne and G. Watt, Parton distributions for the LHC, Eur. Phys. J. C 63 (2009) 189 [arXiv:0901.0002] [INSPIRE].ADSCrossRefGoogle Scholar
  47. [47]
    M. Whalley, D. Bourilkov and R. Group, The Les Houches accord PDFs (LHAPDF) and LHAGLUE, hep-ph/0508110 [INSPIRE].
  48. [48]
    S. Catani, Y.L. Dokshitzer, M.H. Seymour and B.R. Webber, Longitudinally invariant K t clustering algorithms for hadron hadron collisions, Nucl. Phys. B 406 (1993) 187 [INSPIRE].ADSCrossRefGoogle Scholar
  49. [49]
    M. Cacciari and G.P. Salam, Dispelling the N 3 myth for the k t jet-finder, Phys. Lett. B 641 (2006) 57 [hep-ph/0512210] [INSPIRE].ADSCrossRefGoogle Scholar
  50. [50]
    M. Cacciari, G.P. Salam and G. Soyez, FastJet user manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].ADSCrossRefGoogle Scholar
  51. [51]
    G. Corcella et al., HERWIG 6: an event generator for hadron emission reactions with interfering gluons (including supersymmetric processes), JHEP 01 (2001) 010 [hep-ph/0011363] [INSPIRE].ADSCrossRefGoogle Scholar
  52. [52]
    T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 physics and manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].ADSCrossRefGoogle Scholar
  53. [53]
    R. Frederix et al., Four-lepton production at hadron colliders: aMC@NLO predictions with theoretical uncertainties, JHEP 02 (2012) 099 [arXiv:1110.4738] [INSPIRE].ADSCrossRefGoogle Scholar
  54. [54]
    S. Frixione, F. Stoeckli, P. Torrielli and B.R. Webber, NLO QCD corrections in HERWIG++ with MC@NLO, JHEP 01 (2011) 053 [arXiv:1010.0568] [INSPIRE].ADSCrossRefGoogle Scholar
  55. [55]
    P. Torrielli and S. Frixione, Matching NLO QCD computations with PYTHIA using MC@NLO, JHEP 04 (2010) 110 [arXiv:1002.4293] [INSPIRE].ADSCrossRefGoogle Scholar

Copyright information

© SISSA 2012

Authors and Affiliations

  • Rikkert Frederix
    • 1
  • Emanuele Re
    • 2
  • Paolo Torrielli
    • 3
    • 4
  1. 1.Institute for Theoretical PhysicsUniversity of ZürichZürichSwitzerland
  2. 2.Institute for Particle Physics Phenomenology, Department of PhysicsUniversity of DurhamDurhamU.K.
  3. 3.ITPP, EPFLLausanneSwitzerland
  4. 4.PH Department, TH Unit, CERNGeneva 23Switzerland

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