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Determination of the b quark mass at the MZ scale with the DELPHI detector at LEP

  • The DELPHI Collaboration
Experimental Physics

Abstract

An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light=ℓ≡u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions treating mass corrections at next-to-leading order. Measurements of the b quark mass have also been performed for both the b pole mass: Mb and the b running mass: mb(MZ). Data are found to be better described when using the running mass. The measurement yields: \(m_b(M_Z)=2.85\pm0.18 (\text{stat}) \pm0.13 (\text{exp}) \pm0.19 (\text{had}) \pm0.12 (\text{theo}) \text{GeV}/c^2.\)for the CAMBRIDGE algorithm.

This result is the most precise measurement of the b mass derived from a high energy process. When compared to other b mass determinations by experiments at lower energy scales, this value agrees with the prediction of quantum chromodynamics for the energy evolution of the running mass. The mass measurement is equivalent to a test of the flavour independence of the strong coupling constant with an accuracy of 7 ‰.

Keywords

Quark Mass Light Quark Quantum Chromodynamics Energy Evolution Energy Process 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    M. Bilenky, G. Rodrigo, A. Santamaría, Nucl. Phys. B 439, 505 (1995)CrossRefADSGoogle Scholar
  2. 2.
    DELPHI Col., J. Abdallah et al., Eur. Phys. J. C 32, 185 (2004)CrossRefADSGoogle Scholar
  3. 3.
    G. Rodrigo, A. Santamaría, M. Bilenky, Phys. Rev. Lett. 79, 193 (1997); G. Rodrigo, Nucl. Phys. B 54(3), 60 (1997) (Proc. Suppl.)CrossRefADSGoogle Scholar
  4. 4.
    W. Bernreuther, A. Brandenburg, P. Uwer, Phys. Rev. Lett. 79, 189 (1997)CrossRefADSGoogle Scholar
  5. 5.
    P. Nason, C. Oleari, Phys. Lett. B 407, 57 (1997)CrossRefADSGoogle Scholar
  6. 6.
    M. Bilenky et al., Phys. Rev. D 60, 114006 (1999)CrossRefADSGoogle Scholar
  7. 7.
    DELPHI Collaboration, P. Abreu et al., Phys. Lett. B 418, 430 (1998)CrossRefADSGoogle Scholar
  8. 8.
    A. Brandenburg et al., Phys. Lett. B 468, 168 (1999)CrossRefGoogle Scholar
  9. 9.
    ALEPH Collaboration, R. Barate et al., Eur. Phys. J. C 18, 1 (2000)CrossRefADSGoogle Scholar
  10. 10.
    OPAL Collaboration, G. Abbiendi et al., Eur. Phys. J. C 11, 643 (1999)CrossRefADSGoogle Scholar
  11. 11.
    OPAL Collaboration, G. Abbiendi et al., Eur. Phys. J. C 21, 411 (2001)ADSGoogle Scholar
  12. 12.
    R. Tarrach, Nucl. Phys. B 183, 384 (1981)CrossRefADSGoogle Scholar
  13. 13.
    A.X. El-Khadra, M. Luke, Ann. Rev. Nucl. Part. Sci. 52, 201 (2002) [hep-ph/0208114]CrossRefADSGoogle Scholar
  14. 14.
    A.H. Hoang, Frontier of Particle Physics/Handbook of QCD, Vol. 4, ed. by M. Shifman (World Scientific, Singapore, 2001) pp. 2215–2331Google Scholar
  15. 15.
    V.M. Braun, Hadronic, 271–278 [hep-ph/9505317]Google Scholar
  16. 16.
    K.G. Chetyrkin, A. Kwiatkowski, Nucl. Phys. B 461, 3 (1996)CrossRefADSGoogle Scholar
  17. 17.
    K.G. Chetyrkin, B.A. Kniehl, M. Steinhauser, Phys. Rev. Lett. 79, 353 (1997)CrossRefADSGoogle Scholar
  18. 18.
    K.G. Chetyrkin, M. Steinhauser, Phys. Lett. B 408, 320 (1997)CrossRefADSGoogle Scholar
  19. 19.
    Y.L. Dokshitzer et al., JHEP 9708, 001 (1997)Google Scholar
  20. 20.
    S. Catani et al., Phys. Lett. B 269, 432 (1991); N. Brown, W.J. Stirling, Z. Phys. C 53, 629 (1992)CrossRefGoogle Scholar
  21. 21.
    DELPHI Collaboration, P. Aarnio et al., Nucl. Instrum. Methods A 303, 233 (1991)CrossRefGoogle Scholar
  22. 22.
    DELPHI Collaboration, P. Abreu et al., Nucl. Instrum. Methods A 378, 57 (1996)CrossRefGoogle Scholar
  23. 23.
    T. Sjöstrand. Comput. Phys. Commun. 82, 74 (1994)Google Scholar
  24. 24.
    G. Marchesini et al., Comput. Phys. Commun. 67, 465 (1992)CrossRefADSGoogle Scholar
  25. 25.
    DELPHI Collaboration, P. Abreu et al., Z. Phys. C 73, 11 (1996)CrossRefGoogle Scholar
  26. 26.
    T. Sjöstrand et al., Comput. Phys. Commun. 135, 238 (2001); T. Sjöstrand, L. Lönnblad, S. Mrenna, PYTHIA 6.2 Physics and Manual, [hep-ph/0108264]CrossRefGoogle Scholar
  27. 27.
    G. Corcella et al., JHEP 0101, 010 (2001) [hep-ph/ 0011363]; hep-ph/0201201Google Scholar
  28. 28.
    C. Peterson et al., Phys. Rev. D 27, 105 (1983)CrossRefADSGoogle Scholar
  29. 29.
    M.G. Bowler, Z. Phys. C 11, 169 (1981)CrossRefADSGoogle Scholar
  30. 30.
    A. De Rújula, H. Georgi, S.L. Glashow, Phys. Rev. D 12, 147 (1975)CrossRefADSGoogle Scholar
  31. 31.
    M. Eidemüller, Phys. Rev. D 67, 113002 (2003)CrossRefADSGoogle Scholar
  32. 32.
    K. Melnikov, T.v.Ritberger, Phys. Lett. B 482, 99 (2000); K.G. Chetyrkin, M. Steinhauser, Nucl. Phys. B 73, 617 (2000)CrossRefADSGoogle Scholar
  33. 33.
    S. Bethke, Nucl. Phys. B 121, 74 (2003) [hep-ex/0211012] (Proc. Suppl.)CrossRefGoogle Scholar
  34. 34.
    M. Battaglia et al., Phys. Lett. B 556, 41 (2003)CrossRefGoogle Scholar
  35. 35.
    DELPHI Collaboration, P. Abreu et al., Z. Phys. C 65, 555 (1995); G.V. Borisov, C. Mariotti, Nucl. Instrum. Methods A 372, 181 (1996)CrossRefGoogle Scholar
  36. 36.
    G. Borisov, Nucl. Instrum. Methods A 417, 384 (1998)CrossRefGoogle Scholar
  37. 37.
    The LEP/SLD Heavy Flavour Working Group, LEPHF/2001-01, http://lepewwg.web.cern.ch/LEPEWWG/heavy/lephf0101.ps.gzGoogle Scholar
  38. 38.
    DELPHI Collaboration, P. Abreu et al., Eur. Phys. J. C 10, 415 (1999)CrossRefADSGoogle Scholar

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© Springer-Verlag 2006

Authors and Affiliations

  • The DELPHI Collaboration

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