A single track HLT1 trigger

This note describes an alternative approach to the "confirmation" HLT1 trigger strategy, in which a single detached high momentum track is searched for in a region of interest defined by the straight line VELO track segment and the assumed track momentum. It is demonstrated that such an HLT1 trigger is able to reduce the input rate by a factor between 25 and 50 with respect to the L0 output rate depending on the mean number of interactions per bunch crossing while maintaining a high signal efficiency for most B meson decays. The trigger is furthermore found to satisfy the timing requirements imposed by the LHCb running conditions and to be capable of triggering certain key D meson decay modes.