The NLO jet vertex in the small-cone approximation for kt and cone algorithms

Open Access
Regular Article - Theoretical Physics


We determine the jet vertex for Mueller-Navelet jets and forward jets in the small-cone approximation for two particular choices of jet algoritms: the kt algorithm and the cone algorithm. These choices are motivated by the extensive use of such algorithms in the phenomenology of jets. The differences with the original calculations of the small-cone jet vertex by Ivanov and Papa, which is found to be equivalent to a formerly algorithm proposed by Furman, are shown at both analytic and numerical level, and turn out to be sizeable. A detailed numerical study of the error introduced by the small-cone approximation is also presented, for various observables of phenomenological interest. For values of the jet “radius” R = 0.5, the use of the small-cone approximation amounts to an error of about 5% at the level of cross section, while it reduces to less than 2% for ratios of distributions such as those involved in the measure of the azimuthal decorrelation of dijets.


Jets NLO Computations 


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.


  1. [1]
    A.H. Mueller and H. Navelet, An Inclusive Minijet Cross-Section and the Bare Pomeron in QCD, Nucl. Phys. B 282 (1987) 727 [INSPIRE].ADSCrossRefGoogle Scholar
  2. [2]
    A.H. Mueller, Parton distributions at very small x values, Nucl. Phys. Proc. Suppl. 18C (1991) 125 [INSPIRE].ADSCrossRefGoogle Scholar
  3. [3]
    A.H. Mueller, Jets at LEP and HERA, J. Phys. G 17 (1991) 1443 [INSPIRE].ADSCrossRefGoogle Scholar
  4. [4]
    J. Bartels, D. Colferai and G.P. Vacca, The NLO jet vertex for Mueller-Navelet and forward jets: The Quark part, Eur. Phys. J. C 24 (2002) 83 [hep-ph/0112283] [INSPIRE].ADSCrossRefGoogle Scholar
  5. [5]
    J. Bartels, D. Colferai and G.P. Vacca, The NLO jet vertex for Mueller-Navelet and forward jets: The Gluon part, Eur. Phys. J. C 29 (2003) 235 [hep-ph/0206290] [INSPIRE].ADSCrossRefGoogle Scholar
  6. [6]
    D.Y. Ivanov and A. Papa, The next-to-leading order forward jet vertex in the small-cone approximation, JHEP 05 (2012) 086 [arXiv:1202.1082] [INSPIRE].ADSCrossRefGoogle Scholar
  7. [7]
    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
  8. [8]
    S.D. Ellis, Z. Kunszt and D.E. Soper, The One Jet Inclusive Cross-Section at Order α S3 . 1. Gluons Only, Phys. Rev. D 40 (1989) 2188 [INSPIRE].ADSGoogle Scholar
  9. [9]
    M. Furman, Study of a Nonleading QCD Correction to Hadron Calorimeter Reactions, Nucl. Phys. B 197 (1982) 413 [INSPIRE].ADSCrossRefGoogle Scholar
  10. [10]
    B. Jager, M. Stratmann and W. Vogelsang, Single inclusive jet production in polarized pp collisions at O(alpha s3), Phys. Rev. D 70 (2004) 034010 [hep-ph/0404057] [INSPIRE].ADSGoogle Scholar
  11. [11]
    A. Mukherjee and W. Vogelsang, Jet production in (un)polarized pp collisions: dependence on jet algorithm, Phys. Rev. D 86 (2012) 094009 [arXiv:1209.1785] [INSPIRE].ADSGoogle Scholar
  12. [12]
    F. Caporale, D.Y. Ivanov, B. Murdaca and A. Papa, Mueller-Navelet small-cone jets at LHC in next-to-leading BFKL, Nucl. Phys. B 877 (2013) 73 [arXiv:1211.7225] [INSPIRE].ADSMathSciNetCrossRefMATHGoogle Scholar
  13. [13]
    F. Caporale, B. Murdaca, A. Sabio Vera and C. Salas, Scale choice and collinear contributions to Mueller-Navelet jets at LHC energies, Nucl. Phys. B 875 (2013) 134 [arXiv:1305.4620] [INSPIRE].ADSCrossRefGoogle Scholar
  14. [14]
    CMS collaboration, Azimuthal angle decorrelations of jets widely separated in rapidity in pp collisions at \( \sqrt{s} \) = 7 TeV, CMS-PAS-FSQ-12-002 (2012).
  15. [15]
    B. Ducloué, L. Szymanowski and S. Wallon, Confronting Mueller-Navelet jets in NLL BFKL with LHC experiments at 7 TeV, JHEP 05 (2013) 096 [arXiv:1302.7012] [INSPIRE].ADSCrossRefGoogle Scholar
  16. [16]
    V.N. Gribov and L.N. Lipatov, Deep inelastic e p scattering in perturbation theory, Sov. J. Nucl. Phys. 15 (1972) 438 [Yad. Fiz. 15 (1972) 781] [INSPIRE].
  17. [17]
    G. Altarelli and G. Parisi, Asymptotic Freedom in Parton Language, Nucl. Phys. B 126 (1977) 298 [INSPIRE].ADSCrossRefGoogle Scholar
  18. [18]
    Y.L. Dokshitzer, Calculation of the Structure Functions for Deep Inelastic Scattering and e + e Annihilation by Perturbation Theory in Quantum Chromodynamics, Sov. Phys. JETP 46 (1977) 641 [Zh. Eksp. Teor. Fiz. 73 (1977) 1216] [INSPIRE].
  19. [19]
    V.S. Fadin, E.A. Kuraev and L.N. Lipatov, On the Pomeranchuk Singularity in Asymptotically Free Theories, Phys. Lett. B 60 (1975) 50 [INSPIRE].ADSCrossRefGoogle Scholar
  20. [20]
    E.A. Kuraev, L.N. Lipatov and V.S. Fadin, Multi-Reggeon Processes in the Yang-Mills Theory, Sov. Phys. JETP 44 (1976) 443 [Zh. Eksp. Teor. Fiz. 71 (1976) 840] [Erratum ibid. 45 (1977) 199] [INSPIRE].
  21. [21]
    E.A. Kuraev, L.N. Lipatov and V.S. Fadin, The Pomeranchuk Singularity in Nonabelian Gauge Theories, Sov. Phys. JETP 45 (1977) 199 [INSPIRE].ADSMathSciNetGoogle Scholar
  22. [22]
    I.I. Balitsky and L.N. Lipatov, The Pomeranchuk Singularity in Quantum Chromodynamics, Sov. J. Nucl. Phys. 28 (1978) 822 [Yad. Fiz. 28 (1978) 1597] [INSPIRE].
  23. [23]
    D. Colferai, F. Schwennsen, L. Szymanowski and S. Wallon, Mueller Navelet jets at LHCcomplete NLL BFKL calculation, JHEP 12 (2010) 026 [arXiv:1002.1365] [INSPIRE].ADSCrossRefGoogle Scholar

Copyright information

© The Author(s) 2015

Authors and Affiliations

  1. 1.Dipartimento di Fisica e AstronomiaUniversità di Firenze and INFN, Sezione di FirenzeSesto FiorentinoItaly

Personalised recommendations