Full angular spectrum analysis of tensor current contribution to \(A_{cp}(\tau \rightarrow K_{s} \pi \nu_{\tau})\).

  • Lobsang Dhargyal Harish-Chandra Research Institute
Keywords: tau physics, CP violation

Abstract

Babar collaboration has reported an intriguing opposite sign in the integrated decay rate asymmetry \(A_{cp}(\tau \rightarrow K_{s} \pi \nu_{\tau})\) than that of SM prediction from the known \(K^{0} - \bar{K^{0}}\) mixing. Babar's result deviate from the SM prediction by about 2.7\(\sigma\). If the result stands with higher precision in the future experiments, the observed sign anomaly in the \(A_{cp}(\tau \rightarrow K_{s} \pi \nu_{\tau})\) can most likely come only from a NP. In this work we present a full angular spectrum analysis on the contribution to \(A_{cp}(\tau \rightarrow K_{s} \pi \nu_{\tau})\) coming from the tensorial term. Assuming the real part of the NP tensorial coupling is negligible compare to its imaginary part and with \(A_{cp}(\tau \rightarrow K_{s} \pi \nu_{\tau})\) and \(Br(\tau \rightarrow K_{s} \pi \nu_{\tau})\) as data points to fit the imaginary part of the NP coupling, we have been able to fit the result within 1\(\sigma\) of the experimental values.

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Published
2018-11-13
Section
Regular Issue