CP Violation Search in $τ\to ππ^0ν_τ$ Decays

Abstract

Using a sample of 12.2 million $τ$-lepton pairs produced by $e^+e^-$ annihilation at $\sqrt{s}\sim 10.6 $GeV and collected by the CLEO detector, we search for and set limits on CP violation in $τ$-lepton decays. For each event, we require that both $τ$-leptons decay via the mode $τ\ra ππ^0ν$. The search is performed within the context of a multi-Higgs Doublet Model and the imaginary part of the coupling constant parameterizing the non-Standard Model diagram leading to CP violation is constrained to be $-0.046 < \Im{(Λ}) < 0.022$ at 90% CL. The novel search technique is of general utility.