notes (discussion with prof. Tully)

The sum over 3x3 elements seems to be a standard technique.It seems like cristals for both ECAL and HCAL are build in such a way that the energy deposition is mainly within this volume (5x5 is used only for extreme cases).
The values read from ECAL have to be corrected for the calibration (I don't understand if this issue is more or less complicated for ECAL or HCAL).
Anyway the goal of the epxerimental project should be something like:

• implementing the conversion from raw data to energies within CMSSW
• produce files with the energies, so that if you're interested only in these values you don't have to run the whole CMSSW machinery
• try to see how the e/h correction works
  

\sum E over 3x3

Simple implementation :

1. find the element (eta,phi) with maximum energy
2. sum the 3x3 elements aroud this one and consider this as the total energy

The number of events with negative total energy is reduced: now it's 605 over 45165 (it was 811 over 45165). Their values are now in the range [0.;-9.] and most of them are around -6 (it was aroud -50). Are these evts due to fake triggers? of yes, why? am I allowed to simply discard them?

The new energy distributionnow looks like this:
the mean value is different from previously (it was 243 -- nominal 300).

e/h previous procedure

Information from professor Green:

I enclose the code I used. I hope it is readable. The data sets are 5,7,9,10,15,30,50,100,150, and 300 GeV pions from the 2004 test beam. The data was cleaned up by Jordan Damgov – and he can send you the data sets. I first take out e/pi for the HCAL alone so that e/pi is 1 at infinite energy. Then for fits I use 10, 30, 100 and 300 GeV data . The fit function minimizes chisq. The error I used was ~ the energy resolution.

documentation links

documentation CMS
CMS workbook
CMS cpt tdr

Testbeam page

• HCAL TB04 daq portal

CMSSW documentation (doxygen):

• 0_4_1
• 0_5_0