sPHENIX HCal discussion

[John Lajoie <lajoie AT iastate.edu>]

Hi Chris P. (cc'd to hcal-l and jet-structure-l):

    In the HCAL meeting today we heard an estimate from the engineers that a "minimal" frame to hold up the EMCal would be a cylinder of SS310 stainless steel about 2"=5.08 cm in thickness. This would be a little less than 1/3 of an interaction length of material, which would be much less than the full inner HCAL (at one interaction length) or an Al inner HCAL (at about half an interaction length).

    We'd like to try something like this in the simulations to see the effect on jet observables.  Could you whip up a macro to replace the inner HCAL with a cylinder of stainless steel 5 cm in thickness?  I think the most realistic would be to have the cylinder inner radius so that it is at the inner radius of the existing HCAL (snug up against the EMCal).  It's not clear to me what would be the most realistic, but this would allow us to examine the effect of allowing the showers to "open up" in the magnetic field in a region free from absorber between the EMCal and the magnet cryostat.  Depending in what we find, we could adjust this to study other implementations.  I don't think we need to worry about storing any G4hits, etc., in the material - we just need the material there in place of the inner HCAL.

    Since a lot of study has already been done with the 10k Pythia8 jets already produced by Dennis to study the SS310 and Al inner HCAL, my goal would be to run these same events through the modified simulations so we can make comparisons between the studies that have already been done. Depending on what we find we can go from there.

Regards,
John

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John Lajoie

Professor of Physics

Iowa State University

 

(515) 294-6952

lajoie AT iastate.edu

Contact me: john.lajoie