Track finding efficiency in BABAR

We describe several studies to measure the charged track reconstruction efficiency and asymmetry of the B A B AR detector. The first two studies measure the tracking efficiency of a charged particle using τ and initial state radiation decays. The third uses the τ decays to study the asymmetry in tracking, the fourth measures the tracking efficiency for low momentum tracks, and the last measures the reconstruction efficiency of K S 0 particles. The first section also examines the stability of the measurements vs. B A B AR running periods.