The online event selection is crucial to reject most of the events containing
uninteresting background collisions while preserving as much as possible the
interesting physical signals. The b-jet selection is part of the trigger
strategy of the ATLAS experiment and a set of dedicated triggers was
contributing to the event selection for the 2011 running. The b-jets acceptance
is increased and the background reduced by lowering jet transverse energy
thresholds at the first trigger level and applying b-tagging techniques at the
subsequent levels. Different physics channels, especially topologies containing
more than one b-jet where higher rejection factors are achieved, benefit from
using the b-jet trigger. An overview of the b-jet trigger menu and performance
on data is presented.Comment: 4 pages, 6 figures, conference proceedings for PIC201
