The importance of the silicon tracker to the BaBar physics program

The silicon tracker, SVT, built for the BaBar detector has been essential to the execution of the experimentʹs primary goal: the measurement of time-dependent CP violation in B meson decays. Not only has it performed nearly perfectly, it has not even needed any parts replaced for radiation damage, and it has enabled the experiment to carry out a broader physics program than originally envisioned. We review briefly the SVT, its performance, and its key role in three measurements at BaBar: sin 2 β in B → J ψ K S , time-dependent CP violation in B → K S π 0 , and D 0 – D ¯ 0 mixing.