Measurement of Tracking Efficiency

This note describes several methods for measuring the efficiency to reconstruct charged particles in the inner tracker of the CMS detector at the CERN Large Hadron Collider. The first method obtains tracking efficiency for muons and pions by embedding simulated tracks in data. Two additional methods are used to measure the efficiency of tracking muons, isolated and non-isolated, while a fourth method exploits the ratio of four-body and two-body $D^0$ decays to measure tracking efficiency for pions. Results generally indicate that the efficiency is in agreement with expectations from detector simulation within percent uncertainty.