The European Physical Journal C - Particles and Fields

, Volume 33, Issue 1, pp 1–8

Quark mixing, CKM unitarity

The unitarity problem
  • H. Abele
  • E. Barberio
  • D. Dubbers
  • F. Glück
  • J. C. Hardy
  • W. J. Marciano
  • A. Serebrov
  • N. Severijns
experimental physics

DOI: 10.1140/epjc/s2003-01574-8

Cite this article as:
Abele, H., Barberio, E., Dubbers, D. et al. Eur. Phys. J. C (2004) 33: 1. doi:10.1140/epjc/s2003-01574-8

Abstract.

In the Standard Model of elementary particles, quark-mixing is expressed in terms of a 3 x 3 unitary matrix V, the so called Cabibbo-Kobayashi-Maskawa (CKM) matrix. Significant unitarity checks are so far possible for the first row of this matrix. This article reviews the experimental and theoretical information on these matrix elements. On the experimental side, we find a 2.2 \(\sigma\) to 2.7 \(\sigma\) deviation from unitarity, which conflicts with the Standard Model.

Copyright information

© Springer-Verlag Berlin/Heidelberg 2004

Authors and Affiliations

  • H. Abele
    • 1
  • E. Barberio
    • 2
  • D. Dubbers
    • 1
  • F. Glück
    • 3
  • J. C. Hardy
    • 4
  • W. J. Marciano
    • 5
  • A. Serebrov
    • 6
  • N. Severijns
    • 7
  1. 1.Physikalisches Institut der Universität HeidelbergHeidelbergGermany
  2. 2.Physics DepartmentSouthern Methodist UniversityDallas, TXUSA
  3. 3.Research Institute for Nuclear and Particle PhysicsBudapestHungary
  4. 4.Cyclotron InstituteTexas A&M UniversityUSA
  5. 5.Brookhaven National Laboratory UptonNew YorkUSA
  6. 6.Petersburg Nuclear Physics InstituteGatchina, Leningrad DistrictRussia
  7. 7.Instituut voor Kern- en StralingsfysicaKatholieke Universiteit LeuvenLeuvenBelgium