HLT b-Tagging Performance and Strategies

The ability to trigger on b-jets improves the flexibility and physics performance of the High Level Trigger (HLT), especially for topologies containing more than one b-jet. It will be shown that the acceptance for $b$-jets can be increased and background reduced by lowering jet transverse energy thresholds and applying b-tagging selections based on the impact parameter of tracks in jets. This note reviews the b-jet selection in the HLT and discusses its integration into the ATLAS trigger menu.