TY - JOUR
T1 - Computing the temperature dependence of effective CP violation in the standard model
AU - Brauner, Tomas
AU - Taanila, Olli
AU - Tranberg, Anders
AU - Vuorinen, Aleksi
PY - 2012
Y1 - 2012
N2 - 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.
AB - 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.
KW - CP violation
KW - Thermal Field Theory
KW - Standard Model
U2 - 10.1007/jhep11(2012)076
DO - 10.1007/jhep11(2012)076
M3 - Journal article
SN - 1126-6708
VL - 76
SP - 1
EP - 32
JO - Journal of High Energy Physics (Online)
JF - Journal of High Energy Physics (Online)
IS - 11
ER -