1. Testbeam comparisons
arXiv:

2. Jet measurements:
Electromagnetic and
Hadronic calorimetry
Upsilon Spectroscopy:
Excellent momentum resolution tracking in high occupancy
heavy ion events
b-jets:
Secondary vertices

3. Testbeam Setup @ Fermilab
sPHENIX
side view
Midrapidity Configuration (emcal modules + hcal tiles)
Readout Si PMs
Yes – sampling fraction changes with depth which makes the
analysis somewhat tricky

4. EMCal 8 GeV electron shower, only particles with E>7.8MeV shown
Tungsten epoxy with embedded scintillating fiber (Spacal)
Projective in phi (+eta for forward/backward eta, next test beam)
Two Towers in one block

5. HCals 32 GeV p- Midrapidity tiles (steel is identical for high eta)
Babar cryostat mocked up by 3 aluminum plates with X0=1.4
4 Scintillating tiles/row
Measurements with and without EMCal in front

6. In the real world and everything needs to be light tight and supported
Sadly no particle gun available at FTBF

7. GEANT steps
GEANT propagates particles one step at a time. The step size is
determined by the physics processes associated with the current
particle or when a boundary between volumes is crossed
After each step the user stepping method is called with a pointer
to the current volume which has access to the full information
(energy loss, particle momentum at beginning and end of step, …)

8. Our G4Hits
In our stepping method we add the energy loss in each volume and
store the entry and exit coordinates (and for tracking detectors the
momentum at the entry and exit)
G4Hit
We also keep the ancestry for G4Hits so any hit can be traced back
to a primary particle. To reduce size we do not store particles
which do not leave G4Hits and are not in the ancestry of a particle
which created a G4Hit

10. No difference when it comes to em showers (okay - no big surprise
all lists use the same em physics processes)

12. Major differences when it comes to hadronic showers

13. Simulation setup G4 version 10.02 P01 QGSP_BERT_HP
Default Birks constant ( mm/MeV)
Timing window 0-60ns (our electronics)
Light attenuation in scintillator
SiPM pixels added to simulate ADC Pedestal (measured from cosmics)

14. EMCal Energy resolution well reproduced (beam momentum
spread folded in)

15. EMCal Hadron Rejection
Hadron (mostly p-, < 1%K-) rejection as function on energy cut
in 5x5 towers. Should be sensitive to shower sizes

16. HCal Energy deposition well described (inner+outer hcal), peak at
low energy in data due to muons which were not simulated
4 GeV muon mip peak overlaps with hadron peak

17. Hcal e/h 4 GeV contaminated by muons, best description by
0.2mm/MeV Birks constant

18. Summary The resolution seems to be very well reproduced by G4
No real sensitivity on physics lists here
Probably mainly geometry driven
Hadron rejection in emcal shows sensitivity to physics lists (shower size?)
Hcal e/h sensitive to Birks constant