Skip to main content

Study of b-quark mass effects in multijet topologies with the DELPHI detector at LEP

Abstract

The effect of the heavy b-quark mass on the two, three and four-jet rates is studied using LEP data collected by the DELPHI experiment at the Z peak in 1994 and 1995. The rates of b-quark jets and light quark jets (ℓ=uds) in events with n=2, 3, and 4 jets, together with the ratio of two and four-jet rates of b-quarks with respect to light-quarks, Rn bℓ, have been measured with a double-tag technique using the CAMBRIDGE jet-clustering algorithm. A comparison between experimental results and theory (matrix element or Monte Carlo event generators such as PYTHIA, HERWIG and ARIADNE) is done after the hadronisation phase. Using the four-jet observable R4 bℓ, a measurement of the b-quark mass using massive leading-order calculations gives:\(m_b(M_Z) = 3.76 \pm0.32 ({\text{stat}}) \pm0.17 ({\text{syst}}) \pm0.22 ({\text{had}}) \pm0.90 ({\text{theo}})\,\text{GeV}/c^2\,.\) This result is compatible with previous three-jet determinations at the MZ energy scale and with low energy mass measurements evolved to the MZ scale using QCD renormalisation group equations.

References

  1. G. Rodrigo, M. Bilenky, A. Santamaría, Nucl. Phys. B 439, 505 (1995)

    Article  ADS  Google Scholar 

  2. DELPHI Collaboration, P. Abreu et al., Phys. Lett. B 418, 430 (1998)

    Article  ADS  Google Scholar 

  3. S. Martí i García, J. Fuster, S. Cabrera, Nucl. Phys. B Proc. Suppl. 64, 376 (1998)

    Article  ADS  Google Scholar 

  4. ALEPH Collaboration, R. Barate et al., Eur. Phys. J. C 18, 1 (2000)

    Article  ADS  Google Scholar 

  5. OPAL Collaboration, G. Abbiendi et al., Eur. Phys. J. C 21, 411 (2001)

    Article  ADS  Google Scholar 

  6. A. Brandenburg et al., Phys. Lett. B 468, 168 (1999)

    Article  ADS  Google Scholar 

  7. DELPHI Collaboration, J. Abdallah et al., Eur. Phys. J. C 46, 569 (2006)

    Article  ADS  Google Scholar 

  8. Y.L. Dokshitzer et al., JHEP 9708, 001 (1997)

    Article  ADS  Google Scholar 

  9. T. Sjöstrand et al., Comput. Phys. Commun. 135, 238 (2001)

    Article  ADS  MATH  Google Scholar 

  10. T. Sjöstrand et al., PYTHIA 6.2 Physics and Manual, hep-ph/0108264

  11. G. Marchesini et al., Comput. Phys. Commun. 67, 465 (1992)

    Article  ADS  Google Scholar 

  12. G. Corcella et al., JHEP 0101, 010 (2001)

    Article  ADS  Google Scholar 

  13. L. Lönnblad, Comput. Phys. Commun. 71, 15 (1992)

    Article  ADS  Google Scholar 

  14. G. Rodrigo, M. Bilenky, A. Santamaría, Phys. Rev. Lett. 79, 193 (1997)

    Article  ADS  Google Scholar 

  15. W. Bernreuther, A. Brandenburg, P. Uwer, Phys. Rev. Lett. 79, 189 (1997)

    Article  ADS  Google Scholar 

  16. P. Nason, C. Oleari, Phys. Lett. B 407, 57 (1997)

    Article  ADS  Google Scholar 

  17. Particle Data Group, W.-M. Yao et al., J. Phys. G 33, 1 (2006)

    Article  ADS  Google Scholar 

  18. Z. Nagy, Z. Trocsanyi, Phys. Rev. Lett. 79, 3604 (1997)

    Article  ADS  Google Scholar 

  19. Z. Nagy, Z. Trocsanyi, Phys. Rev. D 59, 014020 (1999)

    Article  ADS  Google Scholar 

  20. Z. Nagy, Z. Trocsanyi, Phys. Rev. D 62, 099902 (2000) [Erratum]

    Article  ADS  Google Scholar 

  21. J. Drees, G. Rodrigo, private communication

  22. DELPHI Collaboration, P. Aarnio et al., Nucl. Instrum. Methods A 303, 233 (1991)

    Article  Google Scholar 

  23. DELPHI Collaboration, P. Abreu et al., Nucl. Instrum. Methods A 378, 57 (1996)

    Article  ADS  Google Scholar 

  24. DELPHI Collaboration, P. Abreu et al., Z. Phys. C 73, 11 (1996)

    Article  Google Scholar 

  25. for the tuning of HERWIG 6.2, see [7]

  26. The LEP/SLD Heavy Flavour Working group, LEPHF/2001-01, http://lepewwg.web.cern.ch/LEPEWWG/heavy/lephf0101.ps.gz

  27. DELPHI Collaboration, J. Abdallah et al., Eur. Phys. J. C 32, 185 (2004)

    Article  ADS  Google Scholar 

  28. DELPHI Collaboration, P. Abreu et al., Eur. Phys. J. C 10, 415 (1999)

    Article  ADS  Google Scholar 

  29. M. Bilenky et al., Phys. Rev. D 60, 114006 (1999)

    Article  ADS  Google Scholar 

  30. The LEP QCD Working Group, paper in preparation

  31. M. Battaglia et al., Phys. Lett. B 556, 41 (2003)

    Article  ADS  MathSciNet  Google Scholar 

  32. F. Krauss, G. Rodrigo, Phys. Lett. B 576, 135 (2003)

    Article  ADS  Google Scholar 

  33. S. Catani et al., Nucl. Phys. B 627, 189 (2002)

    Article  ADS  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Consortia

Corresponding author

Correspondence to J. Timmermans.

Rights and permissions

Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License ( https://creativecommons.org/licenses/by-nc/2.0 ), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Reprints and Permissions

About this article

Cite this article

Abdallah, J., Abreu, P., Adam, W. et al. Study of b-quark mass effects in multijet topologies with the DELPHI detector at LEP. Eur. Phys. J. C 55, 525–538 (2008). https://doi.org/10.1140/epjc/s10052-008-0631-5

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1140/epjc/s10052-008-0631-5

Keywords

  • Pole Mass
  • DELPHI Collaboration
  • Monte Carlo Event Generator
  • Hadronisation Correction
  • Gluon Splitting