Search for CP Violation in $\tau \to \pi {\pi }^0{\nu }_{\tau }$ Decay

Abstract

We search for CP non-conservation in the decays of tau leptons produced via $e^{+}{e}^{-}$ annihilation at $\sqrt{s}\sim$ 10.6 GeV. The method uses correlated decays of pairs of tau leptons, each decaying to the $\pi {\pi }^0{\nu }_{\tau }$ final state. The search is done within the framework of a model with a scalar boson exchange. In an analysis of a data sample corresponding to 12.2 million produced tau pairs collected with the CLEO detector, we find no evidence of violation of CP symmetry. We obtain a limit on the imaginary part of the coupling constant parameterizing the relative contribution of diagrams that would lead to CP violation to be $-0.046<\Im (\Lambda )<0.022$ at 90% C.L. This result provides a restriction on CP non-conservation in the tau lepton decays. As a cross check, we study the decay angular distribution and perform a model-independent search for a CP violation effect of a scalar exchange in single $\tau \to \pi {\pi }^0{\nu }_{\tau }$ decays. The limit on the imaginary part of the $\tau$ scalar coupling is $-0.033<\Im (\Lambda )<0.089$ at 90% C.L.

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References in corpus (3)

• Measurement of CP-violating asymmetries in B0 decays to CP eigenstates
• Measurement of the CP Violation Parameter sin(2phi_1) in B^0_d Meson Decays
• P and T Odd Asymmetries in Lepton Flavor Violating Tau Decays

Cited by in corpus (6)

• Search for CP Violation in τ-> Kπν_τDecays
• CP Violation in Hadronic tau Decays
• CP violation in semileptonic tau lepton decays
• Direct CP violation in ${\tau }^{\pm }\to K^{\pm }{\rho }^0(\omega ){\nu }_{\tau }\to K^{\pm }{\pi }^{+}{\pi }^{-}{\nu }_{\tau }$
• SUSY R parity violation and CP asymmetry in semi-leptonic tau-decays
• CLEO Contributions to Tau Physics