Abstract
Triggered by ongoing experimental analyses, we report on a study of the cross section ratio \( \sigma \left( pp\ \to\ t\overline{t} b\overline{b}\right)/\sigma \left( pp\ \to\ t\overline{t} jj\right) \) at the next-to-leading order in QCD, focusing on both present and future collider energies: \( \sqrt{s} \) = 7, 8, 13 TeV. In particular, we provide a comparison between our predictions and the currently available CMS data for the 8 TeV run. We further analyse the kinematics and scale uncertainties of the two processes for a single set of parton distribution functions, with the goal of assessing possible correlations that might help to reduce the theoretical error of the ratio and thus enhance the predictive power of this observable. We argue that the different jet kinematics makes the \( t\overline{t} b\overline{b} \) and \( t\overline{t} jj \) processes uncorrelated in several observables, and show that the scale uncertainty is not significantly reduced when taking the ratio of the cross sections.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
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].
A. Djouadi, The Anatomy of electro-weak symmetry breaking. I: The Higgs boson in the standard model, Phys. Rept. 457 (2008) 1 [hep-ph/0503172] [INSPIRE].
ATLAS collaboration, Search for the Standard Model Higgs boson produced in association with a vector boson and decaying to a b-quark pair with the ATLAS detector, Phys. Lett. B 718 (2012) 369 [arXiv:1207.0210] [INSPIRE].
CMS collaboration, Search for the standard model Higgs boson decaying to bottom quarks in pp collisions at \( \sqrt{s} \) = 7 TeV, Phys. Lett. B 710 (2012) 284 [arXiv:1202.4195] [INSPIRE].
CMS collaboration, Search for the standard model Higgs boson produced in association with a top-quark pair in pp collisions at the LHC, JHEP 05 (2013) 145 [arXiv:1303.0763] [INSPIRE].
CMS collaboration, Search for the standard model Higgs boson produced in association with a W or a Z boson and decaying to bottom quarks, Phys. Rev. D 89 (2014) 012003 [arXiv:1310.3687] [INSPIRE].
K. Desch and M. Schumacher, Model independent determination of the top Yukawa coupling from LHC and LC, Eur. Phys. J. C 46 (2006) 527 [hep-ph/0407159] [INSPIRE].
R. Lafaye, T. Plehn, M. Rauch, D. Zerwas and M. Dührssen, Measuring the Higgs Sector, JHEP 08 (2009) 009 [arXiv:0904.3866] [INSPIRE].
M. Klute, R. Lafaye, T. Plehn, M. Rauch and D. Zerwas, Measuring Higgs Couplings from LHC Data, Phys. Rev. Lett. 109 (2012) 101801 [arXiv:1205.2699] [INSPIRE].
F. Caola and K. Melnikov, Constraining the Higgs boson width with ZZ production at the LHC, Phys. Rev. D 88 (2013) 054024 [arXiv:1307.4935] [INSPIRE].
J.M. Campbell, R.K. Ellis and C. Williams, Bounding the Higgs width at the LHC using full analytic results for gg → e − e + μ − μ +, JHEP 04 (2014) 060 [arXiv:1311.3589] [INSPIRE].
J.M. Campbell, R.K. Ellis and C. Williams, Bounding the Higgs width at the LHC: complementary results from H → WW, Phys. Rev. D 89 (2014) 053011 [arXiv:1312.1628] [INSPIRE].
CMS Collaboration, Constraints on the Higgs boson width from off-shell production and decay to ZZ → ℓℓℓ ′ ℓ ′ and ℓℓνν, CMS-PAS-HIG-14-0202.
V. Drollinger, T. Müller and D. Denegri, Searching for Higgs bosons in association with top quark pairs in the \( {H}_0\ \to\ b\overline{b} \) decay mode, hep-ph/0111312 [INSPIRE].
ATLAS collaboration, Search for the Standard Model Higgs boson produced in association with top quarks in proton-proton collisions at \( \sqrt{s} \) = 7 TeV using the ATLAS detector, ATLAS-CONF-2012-135.
CMS Collaboration, Search for Higgs boson production in association with top quark pairs in pp collisions, CMS-PAS-HIG-12-025.
CMS Collaboration, Search for Higgs Boson Production in Association with a Top-Quark Pair and Decaying to Bottom Quarks or Tau Leptons, CMS-PAS-HIG-13-019.
T. Plehn, G.P. Salam and M. Spannowsky, Fat Jets for a Light Higgs, Phys. Rev. Lett. 104 (2010) 111801 [arXiv:0910.5472] [INSPIRE].
P. Artoisenet, P. de Aquino, F. Maltoni and O. Mattelaer, Unravelling \( t\overline{t} h \) via the Matrix Element Method, Phys. Rev. Lett. 111 (2013) 091802 [arXiv:1304.6414] [INSPIRE].
J. Bramante, A. Delgado and A. Martin, Cornering a Hyper Higgs: Angular Kinematics for Boosted Higgs Bosons with Top Pairs, Phys. Rev. D 89 (2014) 093006 [arXiv:1402.5985] [INSPIRE].
CMS Collaboration, First Measurement of the cross section ratio ttbb/ttjj in pp Collisions at \( \sqrt{s} \), CMS-PAS-TOP-12-024.
CMS Collaboration, Measurement of the cross section ratio ttbb/ttjj in pp Collisions at 8 TeV, CMS-PAS-TOP-13-010.
ATLAS collaboration, A study of heavy flavor quarks produced in association with top quark pairs at \( \sqrt{s} \) = 7 TeV using the ATLAS detector, Phys. Rev. D 89 (2014) 072012 [arXiv:1304.6386] [INSPIRE].
A. Bredenstein, A. Denner, S. Dittmaier and S. Pozzorini, NLO QCD corrections to \( pp\to t\overline{t} b\overline{b}+ X \) at the LHC, Phys. Rev. Lett. 103 (2009) 012002 [arXiv:0905.0110] [INSPIRE].
G. Bevilacqua, M. Czakon, C.G. Papadopoulos, R. Pittau and M. Worek, Assault on the NLO Wishlist: \( pp\to t\overline{t} b\overline{b} \), JHEP 09 (2009) 109 [arXiv:0907.4723] [INSPIRE].
A. Bredenstein, A. Denner, S. Dittmaier and S. Pozzorini, NLO QCD Corrections to Top Anti-Top Bottom Anti-Bottom Production at the LHC: 2. full hadronic results, JHEP 03 (2010) 021 [arXiv:1001.4006] [INSPIRE].
M. Worek, On the next-to-leading order QCD K-factor for top \( t\overline{t} b\overline{b} \) production at the Tevatron, JHEP 02 (2012) 043 [arXiv:1112.4325] [INSPIRE].
G. Bevilacqua, M. Czakon, C.G. Papadopoulos and M. Worek, Dominant QCD Backgrounds in Higgs Boson Analyses at the LHC: A Study of \( pp\to t\overline{t}+2 \) jets at Next-To-Leading Order, Phys. Rev. Lett. 104 (2010) 162002 [arXiv:1002.4009] [INSPIRE].
G. Bevilacqua, M. Czakon, C.G. Papadopoulos and M. Worek, Hadronic top-quark pair production in association with two jets at Next-to-Leading Order QCD, Phys. Rev. D 84 (2011) 114017 [arXiv:1108.2851] [INSPIRE].
S. Hoeche, F. Krauss, P. Maierhoefer, S. Pozzorini, M. Schonherr et al., Next-to-leading order QCD predictions for top-quark pair production with up to two jets merged with a parton shower, arXiv:1402.6293 [INSPIRE].
F. Cascioli, P. Maierhoefer, N. Moretti, S. Pozzorini and F. Siegert, NLO matching for ttbb production with massive b-quarks, arXiv:1309.5912 [INSPIRE].
A. Kardos and Z. Trócsányi, Hadroproduction of \( t\overline{t} \) pair with a \( b\overline{b} \) pair using PowHel, J. Phys. G 41 (2014) 075005 [arXiv:1303.6291] [INSPIRE].
A. Kanaki and C.G. Papadopoulos, HELAC: A Package to compute electroweak helicity amplitudes, Comput. Phys. Commun. 132 (2000) 306 [hep-ph/0002082] [INSPIRE].
C.G. Papadopoulos, PHEGAS: A Phase space generator for automatic cross-section computation, Comput. Phys. Commun. 137 (2001) 247 [hep-ph/0007335] [INSPIRE].
A. Cafarella, C.G. Papadopoulos and M. Worek, Helac-Phegas: A Generator for all parton level processes, Comput. Phys. Commun. 180 (2009) 1941 [arXiv:0710.2427] [INSPIRE].
J. Alwall, A. Ballestrero, P. Bartalini, S. Belov, E. Boos et al., A Standard format for Les Houches event files, Comput. Phys. Commun. 176 (2007) 300 [hep-ph/0609017] [INSPIRE].
T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 Physics and Manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].
Particle Data Group collaboration, J. Beringer et al., Review of Particle Physics (RPP), Phys. Rev. D 86 (2012) 010001 [INSPIRE].
W. Giele, E.W.N. Glover, I. Hinchliffe, J. Huston, E. Laenen et al., The QCD/SM working group: Summary report, hep-ph/0204316 [INSPIRE].
M.R. Whalley, D. Bourilkov and R.C. Group, The Les Houches accord PDFs (LHAPDF) and LHAGLUE, hep-ph/0508110 [INSPIRE].
D. Bourilkov, R.C. Group and M.R. Whalley, LHAPDF: PDF use from the Tevatron to the LHC, hep-ph/0605240 [INSPIRE].
H.-L. Lai, J. Huston, S. Mrenna, P. Nadolsky, D. Stump et al., Parton Distributions for Event Generators, JHEP 04 (2010) 035 [arXiv:0910.4183] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, The Anti-k(t) jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, FastJet User Manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].
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].
M.L. Mangano, M. Moretti, F. Piccinini and M. Treccani, Matching matrix elements and shower evolution for top-quark production in hadronic collisions, JHEP 01 (2007) 013 [hep-ph/0611129] [INSPIRE].
S. Alioli, S.-O. Moch and P. Uwer, Hadronic top-quark pair-production with one jet and parton showering, JHEP 01 (2012) 137 [arXiv:1110.5251] [INSPIRE].
CMS collaboration, Identification of b-quark jets with the CMS experiment, 2013 JINST 8 P04013 [arXiv:1211.4462] [INSPIRE].
H.-L. Lai, M. Guzzi, J. Huston, Z. Li, P.M. Nadolsky et al., New parton distributions for collider physics, Phys. Rev. D 82 (2010) 074024 [arXiv:1007.2241] [INSPIRE].
G. Bevilacqua, M. Czakon, M.V. Garzelli, A. van Hameren, A. Kardos et al., HELAC-NLO, Comput. Phys. Commun. 184 (2013) 986 [arXiv:1110.1499] [INSPIRE].
A. van Hameren, C.G. Papadopoulos and R. Pittau, Automated one-loop calculations: A Proof of concept, JHEP 09 (2009) 106 [arXiv:0903.4665] [INSPIRE].
G. Ossola, C.G. Papadopoulos and R. Pittau, CutTools: A Program implementing the OPP reduction method to compute one-loop amplitudes, JHEP 03 (2008) 042 [arXiv:0711.3596] [INSPIRE].
A. van Hameren, OneLOop: For the evaluation of one-loop scalar functions, Comput. Phys. Commun. 182 (2011) 2427 [arXiv:1007.4716] [INSPIRE].
M. Czakon, C.G. Papadopoulos and M. Worek, Polarizing the Dipoles, JHEP 08 (2009) 085 [arXiv:0905.0883] [INSPIRE].
G. Bevilacqua, M. Czakon, M. Kubocz and M. Worek, Complete Nagy-Soper subtraction for next-to-leading order calculations in QCD, JHEP 10 (2013) 204 [arXiv:1308.5605] [INSPIRE].
A. van Hameren, Kaleu: A General-Purpose Parton-Level Phase Space Generator, arXiv:1003.4953 [INSPIRE].
CMS Collaboration, Measurement of Top-quark Pair Production in Association with a b-quark Pair in pp Collisions at \( \sqrt{s} \) = 8 TeV in Final States with Two Leptons, in preparation.
M.L. Mangano and J. Rojo, Cross Section Ratios between different CM energies at the LHC: opportunities for precision measurements and BSM sensitivity, JHEP 08 (2012) 010 [arXiv:1206.3557] [INSPIRE].
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1403.2046
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Bevilacqua, G., Worek, M. On the ratio of \( t\overline{t} b\overline{b} \) and \( t\overline{t} jj \) cross sections at the CERN Large Hadron Collider. J. High Energ. Phys. 2014, 135 (2014). https://doi.org/10.1007/JHEP07(2014)135
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP07(2014)135