The trigger system of the KLOE experiment

We present the design of the trigger system for the KLOE experiment at the Frascati phi-factory DAPhiNE. The detector consists of a large-volume drift chamber and a calorimeter both immersed in a 0.52 T solenoidal field. The trigger, structured with a first- and a second-decision level, is based on the multiplicity of energy deposits in the calorimeter and of hits in the drift chamber. The selection criteria are described and the efficiency for detecting 0 decays is evaluated using data. (C) 2002 Elsevier Science B.V. All rights reserved.