Four-loop electron EDM matching and timelike τ electric dipole form factor
Chia-Wei Liu, Zi-Yue Zou
Abstract
We compute the four-loop matching of a CP-odd four-τ interaction onto the electron electric dipole moment (EDM), together with the leading timelike τ dipole form factor generated by the same source. Both results are scale independent at this order. Without a local electron dipole, exact electron-EDM cancellation still leaves a timelike τ signal proportional to the four-τ coefficient. Its absorptive part cannot be canceled by a real local dipole, allowing collider limits to constrain the cancellation direction and complement static electron-EDM searches.