Calorimeter (All Cells)

 N
 -----
 The number of cells above a threshold. 

 Exchange 15-Apr-2003:
 Question (HTD): What is the threshold?
 Comment   (LD): ~1800/55k = 3% occupancy and that seems low.
 Answer    (HM): Reco's default threshold.  There is some calibration. We don't
    use the database.  It's after hot-cell-killing (NADA). 

 pT Sum
 ------
 Scaler sum of pT from all cells.

 E Sum
 -----
 Scaler sum of E of all cells.

 IETA
 -----
 Eta of all cells in 1/10th eta units.

 Exchange 15-Apr-2003:
 Question (HTD): Why the horns at |eta| ~ 3.5?
 Answer    (LD): There is alot of physics activity (low Et jets)
    at large eta, close to the beampipe.

 IPHI
 -----
 Phi of all cells in pi/10 units.

 Exchange 15-Apr-2003:
 Question (HTD): Why is every other bin 40% taller?
 Answer    (LD):  I could be the binning (there are exact 64 iphi, from 1 to 64), 
    but the effect is most probably due to the inclusion of the very forward 
    region: for ieta>32, the cells are ~0.2 in phi so only the even iphi cell exist.

 ILYR
 -----
 ILayer. The EM layers are: 1 - EM1; 2 - EM2; 3 to 6 - EM3; 7 - EM4.
 The transition layers are: 8 CCMG (massless gap); 9 - ICD; 10 - ECMG.
 The fine hadronic layers are: 11 - FH1; 12 - FH2; 13 - FH3; 14 - FH4 (EC only).
 The coarse hadronic layers are: 15 - CH1; 16 - CH2 (exists only for 
 9 .le. |ieta| .le. 15); 17 - CH3 (exists only for 9 .le. |ieta| .le. 15).

 Cell E(IPHI vs IETA)
 --------------------
 A 2D-histo of cells over threshold. We are looking for hot cells in this plot.

 ESUM vs IETA
 ------------ 
 The energy summed over ieta ring per event. 

 ESUM vs ILYR
 ------------
 The energy summed over ilayer detector per event.