Performance and Strategies of the b-Jet Selection for the ATLAS High-Level Trigger

The ATLAS detector will operate in a highly challenging environment that requires a sophisticated trigger strategy. The online
b
-jet selection is an important part of the trigger which greatly improves its flexibility and extends the ATLAS physics programme. More specifically,
b
-jet acceptance is increased and background reduced by lowering jet transverse energy thresholds at the first trigger level and then applying
b
-tagging at subsequent levels. Several physics channels, especially those with topologies containing more than one
b
-jet, benefit from requesting this kind of trigger firing. We present an overview of the
b
-jet trigger algorithms and menu at the experiment start-up.