Status of the Hadronic tau Decay Determination of |V_{us}|

Understand

We update the hadronic tau determination of |V_{us}|, showing that current strange branching fractions produce results 2-3 sigma lower than 3-family unitarity expectations.

• Issues related to the size of theoretical uncertainties and results from an alternate, mixed tau-electroproduction sum rule determination (which, by construction, produces a much smaller theoretical uncertainty), are also considered.