Calorimetry for the LC Detector

Hi all, 
there are 3 points to be kept in mind aiming for good calorimetry, 
electromagnetic as well as hadronic. 

(1) missing Et is very important for all kinds of new physics. 
    a large constant term or large non-gaussian tail will kill any 

(2) The resolution of the energy flux measurement from tracker 
    and E-cal is unbeatable. However, if there are overlapping
    high momentum tracks in the center of a jet, the pattern 
    recognition program is likely to assign wrong hits to a track.
    This might result in a completely wrong momentum with the 
    corresponding effect on the energy flux. 
    Excluding those events will bias the sample. An independent 
    calorimetric measurement can check and resolve the problem.

(3) Redundancy: there might be problems with the TPC. Take just the
    Aleph accidents with easily imaginable worse or fatal ends.

Good calorimetry means:
 -  sig(E)/E < .5 sqrt(E/GeV) for the hadronic calorimetry
 -  <= 1% constant term,
 -  good containment: as small as possible non-gaussian tails
Of corse the last 2 points are not independent.

These conditions can only be met, if the calorimeter is sufficiently
segmented: transversly and longitudinally.
Not only a good E-cal is needed, but also a good H-cal is of
equal importance.

Peter Steffen