The European Physical Journal C

, Volume 51, Issue 4, pp 867–873 | Cite as

Initial-state parton shower kinematics for NLO event generators

Regular Article - Theoretical Physics

Abstract

We are developing a consistent method to combine tree-level event generators for hadron collision interactions with those including one additional QCD radiation from the initial-state partons, based on the limited leading-log (LLL) subtraction method, aiming at an application to NLO event generators. In this method, a boundary between non-radiative and radiative processes necessarily appears at the factorization scale (μF). The radiation effects are simulated using a parton shower (PS) in non-radiative processes. It is therefore crucial in our method to apply a PS which well reproduces the radiation activities evaluated from the matrix-element (ME) calculations for radiative processes. The PS activity depends on the applied kinematics model. In this paper we introduce two models for our simple initial-state leading-log PS: a model similar to the ’old’ PYTHIA-PS and a pT-prefixed model motivated by ME calculations. PS simulations employing these models are tested using W-boson production at LHC as an example. Both simulations show a smooth matching to the LLL subtracted W+1 jet simulation in the pT distribution of W bosons, and the summed pT spectra are stable against a variation of μF, despite that the pT-prefixed PS results in an apparently harder pT spectrum.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    S. Catani, M.H. Seymour, Nucl. Phys. B 485, 291 (1997)ADSCrossRefGoogle Scholar
  2. 2.
    S. Catani, S. Dittmaier, M.H. Seymour, Z. Trócsányi, Nucl. Phys. B 627, 189 (2002)ADSCrossRefGoogle Scholar
  3. 3.
    J. Collins, J. High Energ. Phys. 05, 004 (2000)ADSCrossRefGoogle Scholar
  4. 4.
    Y. Chen, J. Collins, N. Tkachuk, J. High Energ. Phys. 06, 015 (2001)ADSCrossRefGoogle Scholar
  5. 5.
    Y. Chen, J. Collins, X. Zu, J. High Energ. Phys. 04, 041 (2002)ADSCrossRefGoogle Scholar
  6. 6.
    S. Frixione, B.R. Webber, J. High Energ. Phys. 06, 029 (2002)ADSCrossRefGoogle Scholar
  7. 7.
    G. Corcella et al., J. High Energ. Phys. 01, 010 (2001)ADSCrossRefGoogle Scholar
  8. 8.
    P. Nason, G. Ridolfi, J. High Energ. Phys. 08, 077 (2006)ADSCrossRefGoogle Scholar
  9. 9.
    Y. Kurihara, J. Fujimoto, T. Ishikawa, K. Kato, S. Kawabata, T. Munehisa, H. Tanaka, Nucl. Phys. B 654, 301 (2003)ADSCrossRefGoogle Scholar
  10. 10.
    T. Ishikawa, T. Kaneko, K. Kato, S. Kawabata, Y. Shimizu, H. Tanaka, KEK Report 92-19 (1993)Google Scholar
  11. 11.
    S. Kawabata, Comput. Phys. Commun. 41, 127 (1986)ADSCrossRefGoogle Scholar
  12. 12.
    S. Kawabata, Comput. Phys. Commun. 88, 309 (1995)ADSCrossRefGoogle Scholar
  13. 13.
    S. Kawabata, private communication on the treatment of negative cross sectionsGoogle Scholar
  14. 14.
    S. Odaka, hep-ph/0604240Google Scholar
  15. 15.
    H. Tanaka, Prog. Theor. Phys. 110, 963 (2003)ADSCrossRefGoogle Scholar
  16. 16.
    H.L. Lai et al., Eur. Phys. J. C 12, 375 (2000)ADSCrossRefGoogle Scholar
  17. 17.
    T. Sjöstrand, S. Mrenna, P. Skands, J. High Energ. Phys. 05, 026 (2006)ADSCrossRefGoogle Scholar
  18. 18.
    T. Sjöstrand, Phys. Lett. B 157, 321 (1985)ADSCrossRefGoogle Scholar
  19. 19.
    M. Bengtsson, T. Sjöstrand, M. van Zijl, Z. Phys. C 32, 67 (1986)ADSCrossRefGoogle Scholar
  20. 20.
    G. Miu, T. Sjöstrand, Phys. Lett. B 449, 313 (1999)ADSCrossRefGoogle Scholar
  21. 21.
    S. Catani, F. Krauss, R. Kuhn, B.R. Webber, J. High Energ. Phys. 11, 063 (2001)ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag / Società Italiana di Fisica 2007

Authors and Affiliations

  1. 1.High Energy Accelerator Research Organization (KEK)TsukubaJapan

Personalised recommendations