Journal of High Energy Physics

, 2016:53

Direct measurement of αQED(mZ2) at the FCC-ee

Open Access
Regular Article - Experimental Physics

Abstract

When the measurements from the FCC-ee become available, an improved determination of the standard-model “input” parameters will be needed to fully exploit the new precision data towards either constraining or fitting the parameters of beyond-the-standard-model theories. Among these input parameters is the electromagnetic coupling constant estimated at the Z mass scale, αQED(mZ2). The measurement of the muon forwardbackward asymmetry at the FCC-ee, just below and just above the Z pole, can be used to make a direct determination of αQED(mZ2) with an accuracy deemed adequate for an optimal use of the FCC-ee precision data.

Keywords

Electroweak interaction e+-e- Experiments 

References

  1. [1]
  2. [2]
    M. Bicer et al., First Look at the Physics Case of TLEP, JHEP 01 (2014) 164.CrossRefADSGoogle Scholar
  3. [3]
    J. Ellis and T. You, Sensitivities of prospective future e + e colliders to decoupled new physics, arXiv:1510.04561 [INSPIRE].
  4. [4]
    ATLAS and CMS collaboration, Combined measurement of the Higgs boson mass in pp collisions at \( \sqrt{s}=7 \) and 8 TeV with the ATLAS and CMS experiments, Phys. Rev. Lett. 114 (2015) 191803.Google Scholar
  5. [5]
    MuLan collaboration, V. Tishchenko et al., Detailed report of the MuLan Measurement of the positive muon lifetime and determination of the Fermi constant, Phys. Rev. D 87 (2013) 052003 [arXiv:1211.0960] [INSPIRE].
  6. [6]
    D. d’Enterria et al., High-precision α S measurements from LHC to FCC-ee, arXiv:1512.05194.
  7. [7]
    M. Davier et al., Reevaluation of the hadronic contributions to the muon g − 2 and to α(m Z2), Eur. Phys. J. C 71 (2011) 1 [Erratum ibid. C 72 (2012) 1515].Google Scholar
  8. [8]
    F. Jegerlehner, Electroweak effective couplings for future precision experiments, Nuovo Cim. C 034S1 (2011) 31 [arXiv:1107.4683] [INSPIRE].Google Scholar
  9. [9]
    A. Leike et al., S-matrix approach to the Z line shape, Phys. Lett. B 273 (1991) 513.CrossRefADSGoogle Scholar
  10. [10]
    M. Boehm et al., Z Physics at LEP-1, volume 1: standard physics, forward-backward asymmetries (1989).Google Scholar
  11. [11]
    F. Zimmermann, Status of the FCC-ee machine, talk given at the 1stFFC general workshop, March 23–29, Washington, U.S.A. (2015).
  12. [12]
    A.L. Kataev and S.A. Larin, Analytical five-loop expressions for the renormalization group QED β-function in different renormalization schemes, Pisma Zh. Eksp. Teor. Fiz. 96 (2012) 64 [arXiv:1205.2810] [INSPIRE].Google Scholar
  13. [13]
    P.A. Baikov et al., Vector correlator in massless QCD at order O(α s4) and the QED β-function at five loop, JHEP 07 (2012) 017.CrossRefADSGoogle Scholar
  14. [14]
    R. Assmann et al., Calibration of centre-of-mass energies at LEP1 for precise measurements of Z properties, Eur. Phys. J. C 6 (1999) 187.CrossRefADSGoogle Scholar
  15. [15]
    M. Koratzinos, A. Blondel, E. Gianfelice-Wendt and F. Zimmermann, FCC-ee: energy calibration, talk given at the 6th International Particle Accelerator Conference 2015 (IPAC 2015), May 3–8, Richmond, Virginia, U.S.A. (2015), arXiv:1506.00933 [INSPIRE].
  16. [16]
    M. Koratzinos, FCC-ee: energy calibration options, talk given at the 1stFFC general workshop, March 23–29, Washington, U.S.A. (2015).
  17. [17]
    E. Lançon and A. Blondel, Determination of the LEP energy spread using experimental constraints, ALEPH 96-136 (1996) [PHYSIC 96-124].
  18. [18]
    R. Tenchini and C. Verzengassi, The physics of the Z and W bosons, World Scientific, Singapore (2008).Google Scholar
  19. [19]
    A. Blondel, Measurement of the effective weak mixing angle at the FCC-ee, talk for the 2st FFC general workshop, April 11–15, Rome, Italy (2016).Google Scholar
  20. [20]
    Particle Data Group collaboration, K. Olive et al., Review of particle physics, Chin. Phys. C 38 (2014) 09001.Google Scholar
  21. [21]
    D. Bardin et al., Analytic approach to the complete set of QED corrections to fermion pair production in e + e annihilation, Nucl. Phys. B 351 (1991) 1.CrossRefADSGoogle Scholar
  22. [22]
    G. Abbendi et al., Angular analysis of the muon pair asymmetry at LEP 1, Phys. Lett. B 516 (2001) 1.ADSGoogle Scholar
  23. [23]
    F. Berends et al., Higher order radiative corrections at LEP energies, Nucl. Phys. B 297 (1988) 429.CrossRefADSMathSciNetGoogle Scholar
  24. [24]
    F. Berends et al., Initial-state radiation at LEP energies and the corrections to Higgs boson production, Nucl. Phys. B 260 (1985) 32.CrossRefADSMathSciNetGoogle Scholar
  25. [25]
    H. Abramowicz et al., The International Linear Collider technical design report — Volume 4: detectors, arXiv:1306.6329 [INSPIRE].
  26. [26]
    D. Bardin et al., ZFITTER v.6.21: a semi-analytical program for fermion pair production in e + e annihilation, Comput. Phys. Commun. 133 (2001) 229.Google Scholar
  27. [27]
    A. Freitas, private communication (Jan., 2016).Google Scholar

Copyright information

© The Author(s) 2016

Authors and Affiliations

  1. 1.CERN, EP DepartmentGenevaSwitzerland

Personalised recommendations