P. Gay Energy flow session 1
Analytic Energy FlowAnalytic Energy Flow
F. Chandez P. GayS. Monteil
CALICE Coll.
P. Gay Energy flow session 2
OutlineOutlineSample & frameworkSample & framework
Photon reconstructionPhoton reconstruction–Photon reconstructionPhoton reconstruction
–Fake rates Fake rates
–hh/photon separation/photon separation
–K° /photon separation K° /photon separation
–Neutron/photon separationNeutron/photon separation
Neutral hadron reconstructionNeutral hadron reconstruction–K° and neutron reconstruction K° and neutron reconstruction
–Neutral/charged hadron separation Neutral/charged hadron separation
First step in EFlow First step in EFlow
SparsificationSparsification
P. Gay Energy flow session 3
Framework Framework Charged w/ Tracking system Si/W e.m. Calorimeter Digital hadron calorimeter
CALIMERO
SampleSampless WW pair production at 800 GeV
And particules extracted from those events
Simulated w/ MOKKA
More info. about CALIMERO in simulation session
P. Gay Energy flow session 4
ProcedureProcedure
Identification and reconstruction of all eflow objects
Ejet = Σ Eem + Eneutral h + Echarged
P. Gay Energy flow session 5
Photon reconstructionPhoton reconstruction E M I L E
Beside the Standard approach ( e.g. REPLIC), new one is developped
Main directions•3D•Long range•No seed
Energy Measurement Intended for Low Energy em showers (1)
(1) Cf. Talk of ECFA-DESY Workshop in PadovaP. Gay, F. LeDiberder, S. Monteil, F. Yermia
P. Gay Energy flow session 6
Energy Measurement Intended for Low Em showers
A terminal pad defines an EMILE object •Every characteristic of the cluster is built through the dij weighing matrix •The information from a pad could be shared by many objects
•The dij terms are determined between every pair of pads in the event but pad j should be on a layer outer than the pad i ie follows the e.m. shower development•All pads are connected w/o any initiate pad (in constrast w/ max. energy pad rule)
P. Gay Energy flow session 7
Photon reconstruction & IDPhoton reconstruction & ID
Variables involved longitudinal and Transverse profiles pad multiplicity Centre-of-gravity position
photons
Charged hadrons≈65% @100 MeV ↙
↙
P. Gay Energy flow session 8
Photon energy resolutionPhoton energy resolution
Fake rate (h±) = 8%
13%/√E ± 1.2%
P. Gay Energy flow session 9
Photon separationPhoton separationMethod based on pattern recognition with mip identification and vertexing (if any) (2)
MOKKA GeometryFew examples w/ γ 1 GeV /π±
10 GeV
(2) Cf. Talk of ECFA-DESY Workshop in Padova
P. Gay Energy flow session 10
Fake rateFake rate Tested with charged and
neutral hadrons from WW
Impact of track information
P. Gay Energy flow session 11
Charged hadron/photon separationCharged hadron/photon separation Tested with pions, kaons and protons
Efficiency as a function of the distance
14.5%/√E ± 2%
P. Gay Energy flow session 12
Neutral hadron/photon separationNeutral hadron/photon separation
Tested with neutral kaons and neutrons
Efficiency as a function of the distance
13%/√E ± 2% neutrons
16%/√E ±.5% kaons
P. Gay Energy flow session 13
Neutral hadron reconstructionNeutral hadron reconstructionA crude approach based on pad multiplicity and em energy
deposited in ECAL
Dedicated work performed by Anatoli and Arthur, cf their talks
Pad multiplicity and em energy are linearly combined
EK≤3GeV↑
36%/√E ± 6%
Behaviour is preciably different w/ neutron
Pad multiplicity
P. Gay Energy flow session 14
Neutral / charged hadron separationNeutral / charged hadron separation
pattern recognition, mip id and vertexing
In development presently will be improved soon
Ereco/EMC
P. Gay Energy flow session 15
Angle reconstructionAngle reconstructionPhoton Neutral Hadron
Isolated particles
Barycentre thru EMILE Geometric Barycentre of fired pads
P. Gay Energy flow session 16
Preliminary resultsPreliminary results
Preliminary means •No tuning per isolated particle •No weighing of the three components•No tuning of the efficiency (wrt fake rate for instance)
P. Gay Energy flow session 17
Preliminary resultsPreliminary results Assuming an ideal sparsification for WW pair production including fake contribution from other particles
Very hard photon are lost, PHOTID bias? Can be easily solved↓
Photons Neutral hadrons
P. Gay Energy flow session 18
Preliminary resultsPreliminary results WW pair production events
(Erec-Emc)/Emc
P. Gay Energy flow session 19
Preliminary resultsPreliminary results
Previous result
Neutral hadron reconstructed replaced by the Truth MC contribution↙
↙
P. Gay Energy flow session 20
SparsificationSparsificationPrevious results assumed an ideal sparsification, not necessarily an advantage e.g. a charged/neutral combination is considered as charged one even if they are separated by 10 cm A complete event has to be divided in rather small sub-objects w/ a
majority of the pads linked to a given particle in only one sub-object.
Sparsification based on simple neighbouring rules on Virtual Tower Pads are grouped in a given tower according a [Θ,φ] direction
θ
φ
High granularity and similar geometry in both ECAL & HCAL
w/ a neighbouring rule of ~10X10, 88% of the Tracks are 88% included in the sub-object and 2 Tracks are connected to a sub-object
Neighbouring rule3X3
5X5
7X7 9X915X15
25X25
<#Track/#sub-object>0.8 1.3 1.6 1.8 2.5 3.5
Then the study based on couple of particles is realistic
P. Gay Energy flow session 21
ConclusionsConclusions No clustering (only sparsification to reduce the size of the problem) New (Stochastic) approach in photon reconstruction (pad can be linked to different particles) dedicated to low energy photons Thanks to High granularity both in ECAL and HCAL Pattern recognition is allowed High granularity and similar geometry in both E- &HCAL allow pseudo-projectivity Results presented are based on study of couple of particles from Physics event configurationMany features have to be tuned and be improved; only a crude
approach has been performed here An effort on neutral hadrons is essential
Anyway the preliminary results based on Pattern recognition (high granularity and similar geometry in both E- & HCAL ) are very promising
⁂ Sparsification w/ virtual tower opens the way for EFlow package