Lepton Universality, |V_{us}| and search for second class current in tau decays

TL;DR

This paper reports on measurements of lepton universality, |V_{us}|, and searches for second class currents in tau decays using data from the BaBar experiment, providing tests of the Standard Model and potential new physics insights.

Contribution

It presents new measurements of |V_{us}| and tests of lepton universality, along with a search for second class currents in tau decays, based on a large dataset from BaBar.

Findings

Consistent tests of lepton universality within experimental uncertainties.

New determinations of |V_{us}| from tau decay modes.

No evidence found for second class currents in tau decays.

Abstract

Several hundred million tau decays have been studied with the BaBar detector at the PEP-II e+e- collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of |V_{us}| using tau- -> e- nubar nu, mu- nubar nu, pi- nu, K- nu and KS0 pi- nu decays, and a search for Second Class Current in tau- -> pi- omega nu decays are presented, where the charge conjugate decay modes are also implied.