Abstract
We present the calculation of the NLO QCD corrections to the electroweak production of top-antitop pairs at the CERN LHC in the presence of a new neutral gauge boson. The corrections are implemented in the parton shower Monte Carlo program POWHEG. Standard Model (SM) and new physics interference effects are properly taken into account. QED singularities, first appearing at this order, are consistently subtracted. Numerical results are presented for SM and Z ′ total cross sections and distributions in invariant mass, transverse momentum, azimuthal angle and rapidity of the top-quark pair. The remaining theoretical uncertainty from scale and PDF variations is estimated, and the potential of the charge asymmetry to distinguish between new physics models is investigated for the Sequential SM and a leptophobic topcolor model.
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References
ATLAS collaboration, Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC, Phys. Lett. B 716 (2012) 1 [arXiv:1207.7214] [INSPIRE].
CMS collaboration, Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC, Phys. Lett. B 716 (2012) 30 [arXiv:1207.7235] [INSPIRE].
ATLAS, CMS collaborations, Combined Measurement of the Higgs Boson Mass in pp Collisions at \( \sqrt{s}=7 \) and 8 TeV with the ATLAS and CMS Experiments, Phys. Rev. Lett. 114 (2015) 191803 [arXiv:1503.07589] [INSPIRE].
K. Hsieh, K. Schmitz, J.-H. Yu and C.P. Yuan, Global Analysis of General SU(2) × SU(2) × U(1) Models with Precision Data, Phys. Rev. D 82 (2010) 035011 [arXiv:1003.3482] [INSPIRE].
T. Ježo, M. Klasen and I. Schienbein, LHC phenomenology of general SU(2) × SU(2) × U(1) models, Phys. Rev. D 86 (2012) 035005 [arXiv:1203.5314] [INSPIRE].
T. Ježo, M. Klasen, D.R. Lamprea, F. Lyonnet and I. Schienbein, NLO+NLL limits on W ′ and Z ′ gauge boson masses in general extensions of the Standard Model, JHEP 12 (2014) 092 [arXiv:1410.4692] [INSPIRE].
T. Ježo, M. Klasen, D.R. Lamprea, F. Lyonnet and I. Schienbein, NLO+NLL limits on W ′ and Z ′ gauge boson masses, arXiv:1508.03539 [INSPIRE].
T. Ježo, M. Klasen, F. Lyonnet, F. Montanet, I. Schienbein and M. Tartare, Can new heavy gauge bosons be observed in ultra-high energy cosmic neutrino events?, Phys. Rev. D 89 (2014) 077702 [arXiv:1401.6012] [INSPIRE].
P. Langacker, The Physics of Heavy Z ′ Gauge Bosons, Rev. Mod. Phys. 81 (2009) 1199 [arXiv:0801.1345] [INSPIRE].
Particle Data Group collaboration, K.A. Olive et al., Review of Particle Physics, Chin. Phys. C 38 (2014) 090001 [INSPIRE].
ATLAS collaboration, Search for high-mass dilepton resonances in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Phys. Rev. D 90 (2014) 052005 [arXiv:1405.4123] [INSPIRE].
CMS collaboration, Search for Resonances in the Dilepton Mass Distribution in pp Collisions at \( \sqrt{s}=8 \) TeV, CMS-PAS-EXO-12-061.
Y. Gao, T. Ghosh, K. Sinha and J.-H. Yu, SU(2) × SU(2) × U(1) interpretations of the diboson and Wh excesses, Phys. Rev. D 92 (2015) 055030 [arXiv:1506.07511] [INSPIRE].
ATLAS, CDF, CMS, D0 collaborations, First combination of Tevatron and LHC measurements of the top-quark mass, arXiv:1403.4427 [INSPIRE].
C.T. Hill, Topcolor: Top quark condensation in a gauge extension of the standard model, Phys. Lett. B 266 (1991) 419 [INSPIRE].
C.T. Hill, Topcolor assisted technicolor, Phys. Lett. B 345 (1995) 483 [hep-ph/9411426] [INSPIRE].
R.M. Harris, C.T. Hill and S.J. Parke, Cross-section for topcolor Z ′ t decaying to \( t\overline{t} \) : version 2.6, hep-ph/9911288 [INSPIRE].
R.M. Harris and S. Jain, Cross sections for Leptophobic Topcolor Z’ Decaying to Top-Antitop, Eur. Phys. J. C 72 (2012) 2072 [arXiv:1112.4928] [INSPIRE].
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 [INSPIRE].
P. Nason, S. Dawson and R.K. Ellis, The One Particle Inclusive Differential Cross-Section for Heavy Quark Production in Hadronic Collisions, Nucl. Phys. B 327 (1989) 49 [Erratum ibid. B 335 (1990) 260] [INSPIRE].
W. Beenakker, H. Kuijf, W.L. van Neerven and J. Smith, QCD Corrections to Heavy Quark Production in \( p\overline{p} \) Collisions, Phys. Rev. D 40 (1989) 54 [INSPIRE].
W. Beenakker, W.L. van Neerven, R. Meng, G.A. Schuler and J. Smith, QCD corrections to heavy quark production in hadron hadron collisions, Nucl. Phys. B 351 (1991) 507 [INSPIRE].
M.L. Mangano, P. Nason and G. Ridolfi, Heavy quark correlations in hadron collisions at next-to-leading order, Nucl. Phys. B 373 (1992) 295 [INSPIRE].
W. Bernreuther, A. Brandenburg, Z.G. Si and P. Uwer, Top quark spin correlations at hadron colliders: Predictions at next-to-leading order QCD, Phys. Rev. Lett. 87 (2001) 242002 [hep-ph/0107086] [INSPIRE].
W. Bernreuther, A. Brandenburg, Z.G. Si and P. Uwer, Top quark pair production and decay at hadron colliders, Nucl. Phys. B 690 (2004) 81 [hep-ph/0403035] [INSPIRE].
W. Beenakker, A. Denner, W. Hollik, R. Mertig, T. Sack and D. Wackeroth, Electroweak one loop contributions to top pair production in hadron colliders, Nucl. Phys. B 411 (1994) 343 [INSPIRE].
C. Kao and D. Wackeroth, Parity violating asymmetries in top pair production at hadron colliders, Phys. Rev. D 61 (2000) 055009 [hep-ph/9902202] [INSPIRE].
J.H. Kuhn, A. Scharf and P. Uwer, Electroweak corrections to top-quark pair production in quark-antiquark annihilation, Eur. Phys. J. C 45 (2006) 139 [hep-ph/0508092] [INSPIRE].
S. Moretti, M.R. Nolten and D.A. Ross, Weak corrections to gluon-induced top-antitop hadro-production, Phys. Lett. B 639 (2006) 513 [Erratum ibid. B 660 (2008) 607] [hep-ph/0603083] [INSPIRE].
W. Bernreuther, M. Fuecker and Z.G. Si, Mixed QCD and weak corrections to top quark pair production at hadron colliders, Phys. Lett. B 633 (2006) 54 [hep-ph/0508091] [INSPIRE].
W. Bernreuther, M. Fuecker and Z.-G. Si, Weak interaction corrections to hadronic top quark pair production, Phys. Rev. D 74 (2006) 113005 [hep-ph/0610334] [INSPIRE].
W. Hollik and M. Kollar, NLO QED contributions to top-pair production at hadron collider, Phys. Rev. D 77 (2008) 014008 [arXiv:0708.1697] [INSPIRE].
J. Gao, C.S. Li, B.H. Li, C.P. Yuan and H.X. Zhu, Next-to-leading order QCD corrections to the heavy resonance production and decay into top quark pair at the LHC, Phys. Rev. D 82 (2010) 014020 [arXiv:1004.0876] [INSPIRE].
F. Caola, K. Melnikov and M. Schulze, Complete next-to-leading order QCD description of resonant Z ′ production and decay into \( t\overline{t} \) final states, Phys. Rev. D 87 (2013) 034015 [arXiv:1211.6387] [INSPIRE].
S. Frixione and B.R. Webber, Matching NLO QCD computations and parton shower simulations, JHEP 06 (2002) 029 [hep-ph/0204244] [INSPIRE].
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].
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].
B. Fuks, M. Klasen, F. Ledroit, Q. Li and J. Morel, Precision predictions for Z ′ -production at the CERN LHC: QCD matrix elements, parton showers and joint resummation, Nucl. Phys. B 797 (2008) 322 [arXiv:0711.0749] [INSPIRE].
M. Klasen, C. Klein-Bösing, K. Kovarik, G. Kramer, M. Topp and J. Wessels, NLO Monte Carlo predictions for heavy-quark production at the LHC: pp collisions in ALICE, JHEP 08 (2014) 109 [arXiv:1405.3083] [INSPIRE].
C. Weydert et al., Charged Higgs boson production in association with a top quark in MC@NLO, Eur. Phys. J. C 67 (2010) 617 [arXiv:0912.3430] [INSPIRE].
M. Klasen, K. Kovarik, P. Nason and C. Weydert, Associated production of charged Higgs bosons and top quarks with POWHEG, Eur. Phys. J. C 72 (2012) 2088 [arXiv:1203.1341] [INSPIRE].
J. Alwall et al., The automated computation of tree-level and next-to-leading order differential cross sections and their matching to parton shower simulations, JHEP 07 (2014) 079 [arXiv:1405.0301] [INSPIRE].
G. Cullen et al., Automated One-Loop Calculations with GoSam, Eur. Phys. J. C 72 (2012) 1889 [arXiv:1111.2034] [INSPIRE].
CDF collaboration, T. Aaltonen et al., Search for Resonant Top-Antitop Production in the Lepton Plus Jets Decay Mode Using the Full CDF Data Set, Phys. Rev. Lett. 110 (2013) 121802 [arXiv:1211.5363] [INSPIRE].
D0 collaboration, V.M. Abazov et al., Search for a Narrow \( t\overline{t} \) Resonance in \( p\overline{p} \) Collisions at \( \sqrt{s}=1.96 \) TeV, Phys. Rev. D 85 (2012) 051101 [arXiv:1111.1271] [INSPIRE].
ATLAS collaboration, A search for \( t\overline{t} \) resonances using lepton-plus-jets events in proton-proton collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, JHEP 08 (2015) 148 [arXiv:1505.07018] [INSPIRE].
CMS collaboration, Search for resonant \( t\overline{t} \) production in proton-proton collisions at \( \sqrt{s}=8 \) TeV, Phys. Rev. D 93 (2016) 012001 [arXiv:1506.03062] [INSPIRE].
J.F. Kamenik, J. Shu and J. Zupan, Review of New Physics Effects in t-tbar Production, Eur. Phys. J. C 72 (2012) 2102 [arXiv:1107.5257] [INSPIRE].
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] [INSPIRE].
D0 collaboration, V.M. Abazov et al., Forward-backward asymmetry in top quark-antiquark production, Phys. Rev. D 84 (2011) 112005 [arXiv:1107.4995] [INSPIRE].
M.R. Buckley, D. Hooper, J. Kopp and E. Neil, Light Z ′ Bosons at the Tevatron, Phys. Rev. D 83 (2011) 115013 [arXiv:1103.6035] [INSPIRE].
M. Czakon, P. Fiedler and A. Mitov, Resolving the Tevatron Top Quark Forward-Backward Asymmetry Puzzle: Fully Differential Next-to-Next-to-Leading-Order Calculation, Phys. Rev. Lett. 115 (2015) 052001 [arXiv:1411.3007] [INSPIRE].
CDF collaboration, T. Aaltonen et al., Measurement of the top quark forward-backward production asymmetry and its dependence on event kinematic properties, Phys. Rev. D 87 (2013) 092002 [arXiv:1211.1003] [INSPIRE].
D0 collaboration, V.M. Abazov et al., Measurement of the forward-backward asymmetry in top quark-antiquark production in ppbar collisions using the lepton+jets channel, Phys. Rev. D 90 (2014) 072011 [arXiv:1405.0421] [INSPIRE].
J.A. Aguilar-Saavedra, W. Bernreuther and Z.G. Si, Collider-independent top quark forward-backward asymmetries: standard model predictions, Phys. Rev. D 86 (2012) 115020 [arXiv:1209.6352] [INSPIRE].
P. Nogueira, Automatic Feynman graph generation, J. Comput. Phys. 105 (1993) 279 [INSPIRE].
M. Tentyukov and J. Fleischer, A Feynman diagram analyzer DIANA, Comput. Phys. Commun. 132 (2000) 124 [hep-ph/9904258] [INSPIRE].
J.A.M. Vermaseren, New features of FORM, math-ph/0010025 [INSPIRE].
S.A. Larin, The Renormalization of the axial anomaly in dimensional regularization, Phys. Lett. B 303 (1993) 113 [hep-ph/9302240] [INSPIRE].
M. Veltman, Diagrammatica: The Path to Feynman rules, Cambridge University Press, Cambridge Lect. Notes Phys. 4 (1994) 1.
F.V. Tkachov, A Theorem on Analytical Calculability of Four Loop Renormalization Group Functions, Phys. Lett. B 100 (1981) 65 [INSPIRE].
K.G. Chetyrkin and F.V. Tkachov, Integration by Parts: The Algorithm to Calculate β-functions in 4 Loops, Nucl. Phys. B 192 (1981) 159 [INSPIRE].
S. Laporta, High precision calculation of multiloop Feynman integrals by difference equations, Int. J. Mod. Phys. A 15 (2000) 5087 [hep-ph/0102033] [INSPIRE].
C. Studerus, Reduze-Feynman Integral Reduction in C++, Comput. Phys. Commun. 181 (2010) 1293 [arXiv:0912.2546] [INSPIRE].
A. von Manteuffel and C. Studerus, Reduze 2 — Distributed Feynman Integral Reduction, arXiv:1201.4330 [INSPIRE].
G. ’t Hooft and M.J.G. Veltman, Scalar One Loop Integrals, Nucl. Phys. B 153 (1979) 365 [INSPIRE].
S. Catani, S. Dittmaier, M.H. Seymour and Z. Trócsányi, The Dipole formalism for next-to-leading order QCD calculations with massive partons, Nucl. Phys. B 627 (2002) 189 [hep-ph/0201036] [INSPIRE].
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].
T. Sjöstrand, S. Mrenna and P.Z. Skands, A Brief Introduction to PYTHIA 8.1, Comput. Phys. Commun. 178 (2008) 852 [arXiv:0710.3820] [INSPIRE].
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].
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].
T. Ježo, Z ′ and W ′ gauge bosons in SU(2) × SU(2) × U(1) models: Collider phenomenology at LO and NLO QCD, Ph.D. Thesis, LPSC, Grenoble (2013).
F. Lyonnet, New heavy resonances: from the Electroweak to the Planck scale, Ph.D. Thesis, LPSC, Grenoble (2014).
R.K. Ellis and J.C. Sexton, QCD Radiative Corrections to Parton Parton Scattering, Nucl. Phys. B 269 (1986) 445 [INSPIRE].
L. Barze, G. Montagna, P. Nason, O. Nicrosini and F. Piccinini, Implementation of electroweak corrections in the POWHEG BOX: single W production, JHEP 04 (2012) 037 [arXiv:1202.0465] [INSPIRE].
L. Barze, G. Montagna, P. Nason, O. Nicrosini, F. Piccinini and A. Vicini, Neutral current Drell-Yan with combined QCD and electroweak corrections in the POWHEG BOX, Eur. Phys. J. C 73 (2013) 2474 [arXiv:1302.4606] [INSPIRE].
R.D. Ball et al., Parton distributions with LHC data, Nucl. Phys. B 867 (2013) 244 [arXiv:1207.1303] [INSPIRE].
NNPDF collaboration, R.D. Ball et al., Parton distributions with QED corrections, Nucl. Phys. B 877 (2013) 290 [arXiv:1308.0598] [INSPIRE].
S. Frixione, P. Nason and G. Ridolfi, A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction, JHEP 09 (2007) 126 [arXiv:0707.3088] [INSPIRE].
E. Remiddi and J.A.M. Vermaseren, Harmonic polylogarithms, Int. J. Mod. Phys. A 15 (2000) 725 [hep-ph/9905237] [INSPIRE].
A.B. Goncharov, Multiple polylogarithms, cyclotomy and modular complexes, Math. Res. Lett. 5 (1998) 497 [arXiv:1105.2076] [INSPIRE].
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Bonciani, R., Ježo, T., Klasen, M. et al. Electroweak top-quark pair production at the LHC with Z ′ bosons to NLO QCD in POWHEG. J. High Energ. Phys. 2016, 141 (2016). https://doi.org/10.1007/JHEP02(2016)141
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DOI: https://doi.org/10.1007/JHEP02(2016)141