Search for Second-Class Currents in tau- -> omega pi- nu_tau

TL;DR

This study searches for second-class currents in tau decays to omega pi nu, using a large dataset, and finds no evidence, setting a new upper limit on their contribution.

Contribution

The paper provides the first stringent upper limit on second-class currents in tau decays to omega pi nu using extensive BABAR data.

Findings

No evidence for second-class currents was observed.

An upper limit of 0.69% was set for the ratio of second- to first-class currents.

The result constrains theoretical models predicting second-class currents.

Abstract

We report on an analysis of $\tau^-$ decaying into $\omega\pi^-\nu_\tau$ with $\omega\to\pi^+\pi^-\pi^0$ using data containing nearly 320 million tau pairs collected with the BABAR detector at the PEP-II asymmetric energy $B$-Factory. We find no evidence for second-class currents and set an upper limit at 0.69% at a 90% confidence level for the ratio of second- to first-class currents.