CP Violating Anomalous Couplings at a 500 GeV e+ e- Linear Collider

Abstract

We study the sensitivity of a 500 GeV $e^{+}{e}^{-}$ Linear Collider to $CP$ violating anomalous couplings. We find that with 50~fb${}^{-1}$, and taking only one non-zero coupling at a time, the process $e^{+}{e}^{-}\to W^{+}{W}^{-}$ can be used to place the 95% confidence level bounds $|{\tilde{\kappa }}_{\gamma }|\le 0.1$, $|{\tilde{\kappa }}_Z|\le 0.1$ and $|g_4^Z|\le 0.1$ from CP even observables. By studying certain distributions in the process $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}\nu \bar{\nu }$ one of the bounds can be improved to $|g_4^Z|\le 0.06$. This process also allows the construction of a CP odd observable which can be used to place bounds on CP violating new physics. At the 95% confidence level we find $|{\tilde{\kappa }}_{\gamma }|\le 0.3$, $|{\tilde{\kappa }}_Z|\le 0.2$ and a much weaker bound for $|g_4^Z|$.

Comments: 18 pages LaTeX, 11 figures using epsf