Transcript PRETTY GOOD SIMULATOR - Istituto Nazionale di Fisica Nucleare

PRETTY GOOD SIMULATION
ERNESTO MIGLIORE*
Università di Torino/INFN
*Disclaimer: not a PGS expert
Ernesto Migliore
MCWS Frascati
28 Feb 06
•
Fortran library (former SHW) by John Conway
Higgs/SUSY Tevatron RUN II
http://www.physics.ucdavis.edu/~conway/research/software/pgs/pgs.html
c
Event loop
c
c
c
c
c
c
c
c
c
|----> pgs_next_event
...
|
|---->
...
|
|---->
...
|
|---->
...
|
|---->
tauola_scan
• “native” interafce to PYTHIA and ISAJET
• interface to user events through STDHEP
Note: hadrons to be supplied by the user
 decays + polarization
pgs_trigger
Detector Simulation
pgs_recon
pgs_user_analysis
|---> pgs_write_event
+ interfaces to HBOOK routines
Ernesto Migliore
MCWS Frascati
Output of selected events through
STDHEP
28 Feb 06
PROCESSING OF EVENTS
pgs_trigger
|
|---> pgs_find_tracks
|---> pgs_fill_cal
make track list
calorimeter energy array
|---> pgs_find_clusters calorimeter energy clusters
|---> pgs_find_TTT_trig
•
From ISTHEP and PHEP
•
Smearing of pT, EEM and EHAD
Fixed size cone R
TTT = /e, , , jet, MET
pgs_recon
|---> pgs_find_RRR
RRR = /e, , , jet, b, c
• Analysis of reconstructed objects on events selected on the
basis of trigger objects
Ernesto Migliore
MCWS Frascati
28 Feb 06
SIMULATION OF THE DETECTOR
• main detector effects:
– pT smearing
– EEM, EHAD smearing
– Energy deposited in towers (granularity of HCAL)
– Tag efficiency (-ID, -tagging, b/c-tagging)
• Detector parameters partly from cards partly hard-coded
Ernesto Migliore
MCWS Frascati
28 Feb 06
LHC_DETECTOR_PARAMETERS
LHC
81
63
0.1
0.099733101
0.1
0.8
0.2
0.00
3.0
0.5
0.70
1.0
2.0
0.000005
0.98
0.30
2.0
Ernesto Migliore
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parameter set name
eta cells in calorimeter
phi cells in calorimeter
CalorimeterHCAL
eta width of calorimeter cells
phi width of calorimeter cells
electromagnetic calorimeter resolution * sqrt(E)
hadronic calorimeter resolution * sqrt(E)
MET resolution
calorimeter cell edge crack fraction
calorimeter cluster finding seed threshold (GeV)
calorimeter cluster finding shoulder threshold (GeV)
calorimeter cluster finder cone size (delta R)
outer radius of tracker (m)
magnetic field (T)
sagitta resolution (m)
5 m pT/pT=4x10-5 pT (GeV)
track finding efficiency
minimum track pt (GeV/c)
tracking eta coverage
MCWS Frascati
28 Feb 06
CALORIMETRY
“Hard-coded”
• single pion energy
– 100% HAD
50% times
– 25% EM + 75% HAD 50% times
• EM cluster definition:
EHAD/EEM<12.5%
(=0)
CDF
Pb+Sci
EM
HAD
MCWS Frascati
CMS
Pb+LAr PbWO4
19 X0
24 X0
26 X0
1 I
1.2 I
1.1 I
Fe+Sci
Cu+Sci
7.2 I
5 I
Fe+Sci
4.5 I
Ernesto Migliore
ATLAS
28 Feb 06
b-TAGGING
Track counting (N=3)
q=# jet q tagged as b /# jets q
CMS
“Hard-coded”
PGS
C.Weiser FNAL 18Jan06
LHCO
v3.3
uds
gluons
c
Ernesto Migliore
=0
eff(b)=50%
MCWS Frascati
28 Feb 06
SIMULATION OF THE DETECTOR
• main detector effects:
– pT smearing
– EEM, EHAD smearing
– Energy deposited in towers (granularity of HCAL)
– Tag efficiency (-ID, -tagging, b/c-tagging)
• Detector parameters partly from cards partly hard-coded
• Not included:
– B deflection of charged tracks (effects on the jet broadness)
– pile-up (relevant for high luminosity analyses)
– underlying event (depending on the MC)
– background processes
Ernesto Migliore
MCWS Frascati
28 Feb 06
OUTLOOK/DISCUSSION
• PGS validation/tuning
– vs. ATLAS and CMS “fast” simulation?
– vs. ATLAS and CMS “full” simulation?
– atlas.par, cms.par, lhcdet.par?
• Which observable in which process (which MC)?
– m(ℓℓ) in Z (+jets)
– MET in W (+jets) or tt
– (isolated )
• Size of the cross-section you want to investigate (nb/pb/fb)
Ernesto Migliore
MCWS Frascati
28 Feb 06