Computing the temperature dependence of effective CP violation in the standard model

Aug, 2012
34 pages
Published in:
  • JHEP 11 (2012) 076
e-Print:
Report number:
  • BI-TP-2012-38

Citations per year

2012201520182021202201234
Abstract: (arXiv)
CP violation in the standard model originates from the Cabibbo-Kobayashi-Maskawa mixing matrix. Upon integrating all fermions out of the theory, its effects are captured by a series of effective nonrenormalizable operators for the bosonic gauge and Higgs fields. We compute the CP-violating part of the effective action to the leading nontrivial, sixth order in the covariant gradient expansion as a function of temperature. In the limit of zero temperature, our result addresses the discrepancy between two independent calculations existing in the literature [1,2]. We find that CP violation in the standard model is strongly suppressed at high temperature, but that at T<1GeV it may be relevant for certain scenarios of baryogenesis. We also identify a selected class of operators at the next, eighth order and discuss the convergence of the covariant gradient expansion.
Note:
  • 34 pages, 5 eps figures, jheppub style/ v2: minor corrections, published version
  • CP violation
  • Standard Model
  • Thermal Field Theory
  • CP: violation
  • temperature dependence
  • expansion: gradient
  • operator: nonrenormalizable
  • effective action
  • baryogenesis
  • suppression