Upper limits on electric and weak dipole moments of W-boson

Abstract

The total cross-sections of the reaction e + e − → W + W − , as measured at LEP-II at centre-of-mass energies between 183 and 207 GeV are used to derive the upper limits on the parameters of CP -violating (P -odd and C-even) triple gauge-boson couplings W W γ and W W Z. The 95% CL limits | κ Z | < 0.13 and | λ Z | < 0.31 are obtained assuming local SU (2) L × U (1) Y gauge invariance which dictates the relations κ Z = − tan 2 θ w κ γ , λ Z = λ γ . Our results are comparable with the previous ones obtained through the analysis of the W decay products.We also discuss the upper limits on the electric dipole moment (EDM) of the W -boson, which follow from the precision measurements of the electron and neutron EDM.