Abstract
Hadronic observables in Z+ jet events can be subject to large NLO corrections at TeV scales, with K-factors that even reach values of order 50 in some cases. We develop a method, LoopSim, by which approximate NNLO predictions can be obtained for such observables, supplementing NLO Z+ jet and NLO Z+ 2-jet results with a unitarity-based approximation for missing higher loop terms. We first test the method against known NNLO results for Drell-Yan lepton p t spectra. We then show our approximate NNLO results for the Z+ jet observables. Finally we examine whether the LoopSim method can provide useful information even in cases without giant K-factors, with results for observables in dijet events that can be compared to early LHC data.
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I. Hinchliffe, F.E. Paige, M.D. Shapiro, J. Soderqvist and W. Yao, Precision SUSY measurements at CERN LHC, Phys. Rev. D 55 (1997) 5520 [hep-ph/9610544] [SPIRES].
CMS collaboration, S. Abdullin et al., Discovery potential for supersymmetry in CMS, J. Phys. G 28 (2002) 469 [hep-ph/9806366] [SPIRES].
The ATLAS collaboration, G. Aad et al., Expected Performance of the ATLAS Experiment-Detector, Trigger and Physics, arXiv:0901.0512 [SPIRES].
CMS collaboration, G.L. Bayatian et al., CMS technical design report, volume II: Physics performance, J. Phys. G 34 (2007) 995 [SPIRES].
M. Spiropulu, SUSY@LHC.CERN.CH, arXiv:0801.0318 [SPIRES].
ATLAS collaboration, T. Yamazaki, Data-driven Estimation of SM Backgrounds for SUSY Searches at the LHC, arXiv:0805.3883 [SPIRES].
ATLAS collaboration, S. Yamamoto, Strategy for early SUSY searches at ATLAS, arXiv:0710.3953 [SPIRES].
M.L. Mangano, Standard Model backgrounds to supersymmetry searches, Eur. Phys. J. C 59 (2009) 373 [arXiv:0809.1567] [SPIRES].
NLO Multileg Working Group collaboration, Z. Bern et al., The NLO multileg working group: Summary report, arXiv:0803.0494 [SPIRES].
SM and NLO Multileg Working Group collaboration, J.R. Andersen et al., The SM and NLO multileg working group: Summary report, arXiv:1003.1241 [SPIRES].
J.M. Campbell, F. Maltoni and F. Tramontano, QCD corrections to J/psi and Upsilon production at hadron colliders, Phys. Rev. Lett. 98 (2007) 252002 [hep-ph/0703113] [SPIRES].
A. Banfi, G.P. Salam and G. Zanderighi, Accurate QCD predictions for heavy-quark jets at the Tevatron and LHC, JHEP 07 (2007) 026 [arXiv:0704.2999] [SPIRES].
J.M. Butterworth, A.R. Davison, M. Rubin and G.P. Salam, Jet substructure as a new Higgs search channel at the LHC, Phys. Rev. Lett. 100 (2008) 242001 [arXiv:0802.2470] [SPIRES].
C.W. Bauer and B.O. Lange, Scale setting and resummation of logarithms in pp → V + jets, arXiv:0905.4739 [SPIRES].
A. Denner, S. Dittmaier, T. Kasprzik and A. Muck, Electroweak corrections to W + jet hadroproduction including leptonic W-boson decays, JHEP 08 (2009) 075 [arXiv:0906.1656] [SPIRES].
C. Oleari, Status of POW HEG, presentation at the MC4LHC readiness workshop, CERN, Geneva, March 2010 [http://indico.cern.ch/getFile.py/access?contribId=46&sessionId=3&resId=0&materialId=slides&confId=74601].
F. Febres Cordero, L. Reina and D. Wackeroth, W- and Z-boson production with a massive bottom-quark pair at the Large Hadron Collider, Phys. Rev. D 80 (2009) 034015 [arXiv:0906.1923] [SPIRES].
T. Binoth, T. Gleisberg, S. Karg, N. Kauer and G. Sanguinetti, NLO QCD corrections to ZZ+jet production at hadron colliders, Phys. Lett. B 683 (2010) 154 [arXiv:0911.3181] [SPIRES].
J.M. Campbell and R.K. Ellis, An update on vector boson pair production at hadron colliders, Phys. Rev. D 60 (1999) 113006 [hep-ph/9905386] [SPIRES].
J. Campbell et al., MCFM-Monte Carlo for FeMtobarn processes, http://mcfm.fnal.gov.
M. Cacciari, G.P. Salam and G. Soyez, The anti-k t jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [SPIRES].
C.F. Berger et al., Next-to-Leading Order QCD Predictions for W+3-Jet Distributions at Hadron Colliders, Phys. Rev. D 80 (2009) 074036 [arXiv:0907.1984] [SPIRES].
P. Ciafaloni and D. Comelli, The importance of weak bosons emission at LHC, JHEP 09 (2006) 055 [hep-ph/0604070] [SPIRES].
E.W. Nigel Glover and J. Pires, Antenna subtraction for gluon scattering at NNLO, JHEP 06 (2010) 096 [arXiv:1003.2824] [SPIRES].
P. Artoisenet, J.M. Campbell, J.P. Lansberg, F. Maltoni and F. Tramontano, υ Production at Fermilab Tevatron and LHC Energies, Phys. Rev. Lett. 101 (2008) 152001 [arXiv:0806.3282] [SPIRES].
S. Catani, F. Krauss, R. Kuhn and B.R. Webber, QCD Matrix Elements + Parton Showers, JHEP 11 (2001) 063 [hep-ph/0109231] [SPIRES].
Y.L. Dokshitzer, G.D. Leder, S. Moretti and B.R. Webber, Better Jet Clustering Algorithms, JHEP 08 (1997) 001 [hep-ph/9707323] [SPIRES].
M. Wobisch and T. Wengler, Hadronization corrections to jet cross sections in deep-inelastic scattering, hep-ph/9907280 [SPIRES].
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] [SPIRES].
M. Cacciari, G.P. Salam and G. Soyez, The FastJet package, http://fastjet.fr/.
S. Catani, Y.L. Dokshitzer, M. Olsson, G. Turnock and B.R. Webber, New clustering algorithm for multi-jet cross-sections in e + e − annihilation, Phys. Lett. B 269 (1991) 432 [SPIRES].
S.D. Ellis and D.E. Soper, Successive combination jet algorithm for hadron collisions, Phys. Rev. D 48 (1993) 3160 [hep-ph/9305266] [SPIRES].
A. Banfi, G.P. Salam and G. Zanderighi, Infrared safe definition of jet flavor, Eur. Phys. J. C 47 (2006) 113 [hep-ph/0601139] [SPIRES].
S. Hoeche, F. Krauss, S. Schumann and F. Siegert, QCD matrix elements and truncated showers, JHEP 05 (2009) 053 [arXiv:0903.1219] [SPIRES].
S. Frixione, Isolated photons in perturbative QCD, Phys. Lett. B 429 (1998) 369 [hep-ph/9801442] [SPIRES].
M. Ciafaloni, P. Ciafaloni and D. Comelli, Bloch-Nordsieck violating electroweak corrections to inclusive TeV scale hard processes, Phys. Rev. Lett. 84 (2000) 4810 [hep-ph/0001142] [SPIRES].
Z. Nagy, Three-jet cross sections in hadron hadron collisions at next-to-leading order, Phys. Rev. Lett. 88 (2002) 122003 [hep-ph/0110315] [SPIRES].
Z. Nagy, Next-to-leading order calculation of three jet observables in hadron hadron collision, Phys. Rev. D 68 (2003) 094002 [hep-ph/0307268] [SPIRES].
S. Catani and M.H. Seymour, The Dipole Formalism for the Calculation of QCD Jet Cross Sections at Next-to-Leading Order, Phys. Lett. B 378 (1996) 287 [hep-ph/9602277] [SPIRES].
S. Catani and M.H. 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] [SPIRES].
K. Melnikov and F. Petriello, Electroweak gauge boson production at hadron colliders through O(α s 2), Phys. Rev. D 74 (2006) 114017 [hep-ph/0609070] [SPIRES].
S. Catani, L. Cieri, G. Ferrera, D. de Florian and M. Grazzini, Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO, Phys. Rev. Lett. 103 (2009) 082001 [arXiv:0903.2120] [SPIRES].
J.M. Campbell and R.K. Ellis, Radiative corrections to Z b anti-b production, Phys. Rev. D 62 (2000) 114012 [hep-ph/0006304] [SPIRES].
S. Catani and M. Grazzini, An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC, Phys. Rev. Lett. 98 (2007) 222002 [hep-ph/0703012] [SPIRES].
M. Grazzini, Vector boson production at hadron colliders, http://theory.fi.infn.it/grazzini/dy.html.
J.M. Campbell, R.K. Ellis and D.L. Rainwater, Next-to-leading order QCD predictions for W + 2jet and Z + 2jet production at the CERN LHC, Phys. Rev. D 68 (2003) 094021 [hep-ph/0308195] [SPIRES].
C.F. Berger et al., Next-to-Leading Order QCD Predictions for Z,γ ∗ +3-Jet Distributions at the Tevatron, arXiv:1004.1659 [SPIRES].
M. Klasen and G. Kramer, Dijet cross-sections at o (αα − S 2 ) in photon-proton collisions, Phys. Lett. B 366 (1996) 385 [hep-ph/9508337] [SPIRES].
S. Frixione and G. Ridolfi, Jet photoproduction at HERA, Nucl. Phys. B 507 (1997) 315 [hep-ph/9707345] [SPIRES].
ZEUS collaboration, S. Chekanov et al., Dijet production in neutral current deep inelastic scattering at HERA, Eur. Phys. J. C 23 (2002) 13 [hep-ex/0109029] [SPIRES].
H1 collaboration, A. Aktas et al., Inclusive dijet production at low Bjorken-x in deep inelastic scattering, Eur. Phys. J. C 33 (2004) 477 [hep-ex/0310019] [SPIRES].
A. Banfi and M. Dasgupta, Dijet rates with symmetric E(t) cuts, JHEP 01 (2004) 027 [hep-ph/0312108] [SPIRES].
J. Alwall et al., Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions, Eur. Phys. J. C 53 (2008) 473 [arXiv:0706.2569] [SPIRES].
N. Lavesson and L. Lönnblad, Extending CKKW-merging to One-Loop Matrix Elements, JHEP 12 (2008) 070 [arXiv:0811.2912] [SPIRES].
K.R. Ellis, K. Melnikov and G. Zanderighi, W+3 jet production at the Tevatron, Phys. Rev. D 80 (2009) 094002 [arXiv:0906.1445] [SPIRES].
G. Bevilacqua, M. Czakon, C.G. Papadopoulos and M. Worek, Dominant QCD Backgrounds in Higgs Boson Analyses at the LHC: A Study of \( pp \to t\bar{t} + 2 \) jets at Next-To-Leading Order, Phys. Rev. Lett. 104 (2010) 162002 [arXiv:1002.4009] [SPIRES].
A. Bassetto, M. Ciafaloni and G. Marchesini, Jet Structure and Infrared Sensitive Quantities in Perturbative QCD, Phys. Rept. 100 (1983) 201 [SPIRES].
F. Fiorani, G. Marchesini and L. Reina, Soft gluon factorization and multi-gluon amplitude, Nucl. Phys. B 309 (1988) 439 [SPIRES].
Y.L. Dokshitzer, G. Marchesini and G. Oriani, Measuring color flows in hard processes: Beyond leading order, Nucl. Phys. B 387 (1992) 675 [SPIRES].
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Rubin, M., Salam, G.P. & Sapeta, S. Giant QCD K-factors beyond NLO. J. High Energ. Phys. 2010, 84 (2010). https://doi.org/10.1007/JHEP09(2010)084
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DOI: https://doi.org/10.1007/JHEP09(2010)084