Taggers

By t a g g e r s, we denote detectors that detect the presence of any kind of detectable stable particle, charged or neutral, and also has some proportionality between signal and incoming energy. Hence, they should be described analogously to modular calorimeters (with a bad energy resolution), sensitive to minimum ionising particles. If the taggers are sensitive to electrons and photons, and sees muons and charged hadrons as minimum ionising particles, the detector type should be set to 'electro-magnetic', if it also detects neutral hadrons it should be set to 'combined'.

Internally, SGV treats taggers as calorimeters, and the data from them will be in the shower-part at the particle information common-block. In the analysis code, the taggers can be used by looking for the existence of a signal in them. The shower start-point will be at the center of the hit module, and can easily be modified to a module number. If shower clustering was done, one is assured that there will only be one cluster per tagger module, even if several tracks went through the same one. Care should be taken that the measured momentum etc. of particles only detected by a tagger is not used for total energy calculation, and the like.