Search for CP Violation in \tau -> K\pi\nu_\tau Decays

TL;DR

This paper reports a search for CP violation in tau decays to K pi nu final states, finding no evidence and setting limits on possible CP-violating contributions.

Contribution

It provides the first experimental constraints on CP violation in tau to K pi nu decays, establishing confidence limits on the imaginary part of the coupling constant Lambda.

Findings

No evidence of CP violation was observed.

Confidence limits on Im(Lambda) are -0.155 to 0.047 at 90% C.L.

Sets new bounds on CP-violating processes in tau decays.

Abstract

We search and find no evidence for CP violation in tau decays into the K pi nu final state. We provide confidence limits on the imaginary part of the coupling constant Lambda, describing a relative contribution of the CP violating processes with respect to the Standard Model, to be -0.155 < Im(Lambda) < 0.047 at 90% C.L.