1. papas: CMS single particle tuning
Colin Bernet, Gael Touquet

2. papas Papas, CMS, B=3.8 T Hb bbar in heppy Zmumu
take stable particles
ROOT
Analysis
high-level
processing
Papas
particle simulation & reconstruction
Pythia8
eeZHmumubb
Ntuples
FCC EDM
in heppy
Papas, CMS, B=3.8 T
extrapolate
simulate: tracks
ecal clusters
HCAL clusters
Hb bbar
Zmumu
reconstruct particles

3. Today This presentation: Alice’s presentation
tuning the single particle response of the CMS model (Gaël Touqet)
jets are made from single particles!
Alice’s presentation
refinement of the python code, and port to C++

4. Photon ECAL deposit = photon energy energy smearing threshold
Gaël Touquet
ECAL deposit = photon energy
energy smearing
threshold
ECAL cluster not linked to a track  PF photon

5. CMS ECAL tuning : resolution
Gaël Touquet
Before
After

6. CMS ECAL tuning: thresholds
Gaël Touquet
Before
After

7. Neutral hadron
Gaël Touquet
HCAL cluster not linked to a track  neutral hadron
ECAL deposit probability according to ECAL interaction lengths
if ECAL: 0 – 80% of neutral hadron energy
the rest in HCAL
energy smearing
hcal response
thresholds
ECAL cluster not linked to a track  PF photon

8. CMS HCAL tuning: thresholds
Gaël Touquet
Before
After

9. CMS HCAL tuning : response
Gaël Touquet
Before
After
<Erec/Egen>
<Erec/Egen>

10. Charged hadron simulation
Gaël Touquet
clusters
linked to track
 not used
Calorimeter deposits as neutral hadrons
track:
pT smearing
acceptance model
Track
PF charged hadron

11. Charged hadrons too much reconstructed energy in CMS full sim
Gaël Touquet

12. Charged hadrons too much reconstructed energy in CMS full sim
Gaël Touquet

13. Charged hadron simulation
Gaël Touquet
clusters
linked to track
 not used
In CMS full sim, hadron showers give rise to satellite clusters
not modelled in papas
satellite cluster
fake PF neutral hadron
energy double counting
Track
PF charged hadron

14. All events
Gaël Touquet

15. Events without satellite clusters
Gaël Touquet
Other contributions from Gaël:
solved bug with random numbers: papas now reproducible
tuned the CMS endcap region (was bad!)
all merged
Will try and improve the CMS particle flow algorithm instead of tuning papas to reproduce this problem

16. Next steps
Perform a full validation w/r to CMS with FCC-ee physics events
e.g. compare jet energy resolution and response
Do the same for Delphes
Gaël joins CMS for a PhD thesis!
He will work on the CMS particle flow algorithm, papas, heppy, Htau tau