CP violation of tau -> K pi(eta, eta') nu decays

TL;DR

This paper investigates direct CP violation in tau decays to K pi(eta, eta') nu, using a chiral Lagrangian with scalar and vector mesons, and explores the impact of a new CP-violating phase in a two Higgs doublet model.

Contribution

It introduces a detailed calculation of form factors including meson loops and analyzes CP violation effects within a two Higgs doublet framework.

Findings

CP violation depends on the new CP-violating phase and form factor strong phases.

The interference of L=0 and L=1 amplitudes can be extracted from asymmetries.

The model predicts measurable CP asymmetries in tau decays.

Abstract

We study direct CP violation of tau -> K pi(eta,eta')nu decays. By studying the forward and backward asymmetry, the interference of L=0 and L=1 amplitudes of the hadronic system can be extracted. By including the scalar and vector mesons into the chiral Lagrangian, we compute the form factors which correspond to L=0 and L=1 angular momentum state of the hadronic system. We include real and imaginary parts of the one loop corrections to the self-energies of the scalar and vector mesons. The direct CP violation of the forward and backward asymmetry is computed using a two Higgs doublet model in which a new CP violating phase is introduced. We show how the CP violation of the forward and the backward asymmetry may depend on the new CP violating phase and the strong phase of the form factors.