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P. Gay Energy flow session1 Analytic Energy Flow F. Chandez P. Gay S. Monteil CALICE Coll.

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Presentation on theme: "P. Gay Energy flow session1 Analytic Energy Flow F. Chandez P. Gay S. Monteil CALICE Coll."— Presentation transcript:

1 P. Gay Energy flow session1 Analytic Energy Flow F. Chandez P. Gay S. Monteil CALICE Coll.

2 P. Gay Energy flow session2 Outline Sample & framework Sample & framework Photon reconstruction Photon reconstruction – Photon reconstruction – Fake rates – h  /photon separation – K° /photon separation – Neutron/photon separation Neutral hadron reconstruction Neutral hadron reconstruction – K° and neutron reconstruction – Neutral/charged hadron separation First step in EFlow First step in EFlow Sparsification Sparsification

3 P. Gay Energy flow session3 Framework Charged w/ Tracking system Si/W e.m. Calorimeter Digital hadron calorimeter CALIMERO Samples WW pair production at 800 GeV And particules extracted from those events Simulated w/ MOKKA More info. about CALIMERO in simulation session

4 P. Gay Energy flow session4 Procedure Identification and reconstruction of all eflow objects E jet = Σ E em + E neutral h + E charged

5 P. Gay Energy flow session5 Photon 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 Padova P. Gay, F. LeDiberder, S. Monteil, F. Yermia

6 P. Gay Energy flow session6 Energy Measurement Intended for Low Em showers  A terminal pad defines an EMILE object Every characteristic of the cluster is built through the d ij weighing matrix The information from a pad could be shared by many objects The d ij 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)

7 P. Gay Energy flow session7 Photon reconstruction & ID Variables involved longitudinal and Transverse profiles pad multiplicity Centre-of-gravity position photons Charged hadrons ≈65% @100 MeV ↙ ↙

8 P. Gay Energy flow session8 Photon energy resolution Fake rate (h ± ) = 8% 13%/√E ± 1.2%

9 P. Gay Energy flow session9 Photon separation Method based on pattern recognition with mip identification and vertexing (if any) (2) MOKKA Geometry Few examples w/ γ 1 GeV /π ± 10 GeV (2) Cf. Talk of ECFA-DESY Workshop in Padova

10 P. Gay Energy flow session10 Fake rate Tested with charged and neutral hadrons from WW Impact of track information

11 P. Gay Energy flow session11 Charged hadron/photon separation Tested with pions, kaons and protons Efficiency as a function of the distance 14.5%/√E ± 2%

12 P. Gay Energy flow session12 Neutral hadron/photon separation Tested with neutral kaons and neutrons Efficiency as a function of the distance 13%/√E ± 2% neutrons 16%/√E ±.5% kaons

13 P. Gay Energy flow session13 Neutral hadron reconstruction A 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 E K ≤3GeV ↑ 36%/√E ± 6% Behaviour is preciably different w/ neutron Pad multiplicity

14 P. Gay Energy flow session14 Neutral / charged hadron separation pattern recognition, mip id and vertexing In development presently will be improved soon E reco /E MC

15 P. Gay Energy flow session15 Angle reconstruction Photon Neutral Hadron Isolated particles Barycentre thru EMILE Geometric Barycentre of fired pads

16 P. Gay Energy flow session16 Preliminary results Preliminary means No tuning per isolated particle No weighing of the three components No tuning of the efficiency (wrt fake rate for instance)

17 P. Gay Energy flow session17 Preliminary 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

18 P. Gay Energy flow session18 Preliminary results WW pair production events (E rec -E mc )/E mc

19 P. Gay Energy flow session19 Preliminary results Previous result Neutral hadron reconstructed replaced by the Truth MC contribution ↙ ↙

20 P. Gay Energy flow session20 Sparsification Previous 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 rule 3X35X57X79X9 15X 15 25X 25 Then the study based on couple of particles is realistic

21 P. Gay Energy flow session21 Conclusions  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 configuration  Many 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

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