The LHCb prompt charm triggers

Abstract

The LHCb experiment has fully reconstructed close to 10^9 charm hadron decays---by far the world's largest sample. During the 2011-2012 running periods, the effective proton-proton beam crossing rate was 11-15 MHz while the rate at which events were written to permanent storage was 3-5 kHz. Prompt charm candidates (produced at the primary interaction vertex) were selected using a combination of exclusive and inclusive high level (software) triggers in conjunction with low level hardware triggers. The efficiencies, background rates, and possible biases of the triggers as they were implemented will be discussed, along with plans for the running at 13 TeV in 2015 and subsequently in the upgrade era.