CAT plenary meeting VLIMANT Jean-RochLPNHE13 may 2003 T42 algorithm dedicated webpage : T42 + Top_analyze +d0root_analysis  Principle & Implementation  Effect on cells  Effect on EM objects

T42 Principle : reject isolated medium cells Named after an algorithm used in H1  Reject negative energy cells  Select high signal cells (4 sigma)  Keep their significant neighbours (2 sigma)  Thresholds 2  is 2.5  at the moment

cal_t42 Package created after cal_nada classes Classes :  Calt42Struct : neighbourhood object  Calt42 : container for cell lists  Calt42Chunk : container for Calt42 object  Calt42Reco : –Does the cleaning and creates a Calt42Chunk with rejected cells and modify/or not the CalDataChunk (killing/shadow mode). –Get the neighbourhood info from a Calt42Struct object which allows a linear algorithm complexity.  Calt42Combine : –When shadow mode in d0reco : produces a clean CalDataChunk –When killing mode in d0reco : produces a un-clean CalDataChunk  And registerers RegCalt42Reco RegCalt42Combine

Calt42Reco 1/2

Calt42Reco 2/2

Calt42Struct class content  Objects –spine : array[81600] of structured object  Mapped to ieta, iphi, layer by : INDEX = iphi + 64( layer - 1 ) ( ieta + 37 ) - 1 –Structured object fields  sigma : tells the noise rms of the cell  pointers to all possible neighbors within the array  single pointer to be assigned to a CalCell available in CalDataChunk  Methods –Access –Fields initialiaser The Neighbourhood information is read from the file STRUCTURE.dat

Calt42Struct use in Calt42Reco

Calt42Struct Neighbourhood information  How to check ? –Trust me –WebPage : check rules and pictures –Calt42Struct::PrintNeighbours(ieta,iphi,layer) –Calorimeter display : to be written  Regular cells –normal –out of fine layers (3,4,5,6) –near fine layers (2,7) –Layer 32/33  Exceptions cells –Neighbours above or below splited into different layers –Intercryostat and nearby cells

Calt42Combine Only for DST files Only one parameter  Do you want the t42 cleaned CalDataChunk ? Automatic detection of the d0reco mode by cell matching. Modification of the CalDataChunk

In the framework need for post-reconstruction when shadow mode For DST / TMB In the main rcp String packagename = “…unpack T42 rebuild …” T42 = // process the t42 algo or T42 = // only combine chunks “rebuild” must reconstruct the object chunks you want to see the effect on

Study effects on data Data sets  EM stream data evts of WZskim-emStream-*-*.raw_p under the project name WZstreamTMBp13.06  Unstreamed data evts in files recoT_all_ _mrg_*-*.raw_p Global_CMT run  Min/Zero bias Wzskim evts of Wzskim-mzbiasStream-*-*.raw_p Under the project name mzbias_mvh.all1

Population report unstreamed data

Cells effect close to beam EC regions  More rejection than expected noise ! –Too many cells with negative energy arbitrarily increases the rejection; They are not from gaussian noise only, probably due to pile-up –This is due to cell close to the beam  Negative energy rejection is unsuited to this region  Should be treated separately Keep untouched above |ieta|=33(CH) and 32 (EM, FH) Even lower for FH ?

Region Labels

Region report emstream data

Region report WZstream data with problems

Region report unstreamed data

Region report unstreamed data with problems

Region report minimum/zero bias data

Region report minimum/zero bias data with problems

Cells effect away from beam CC regions  Statistically noise like rejection –Always about the same number of negative cells in the event : probably noise and it is always rejected –Coherent number of rejected cells Region occupancies show signal presence –~40% on unstreamed data  Cells clustering decreases with the distance to interaction point  -/+ rejected ratio for region threshold tuning ? Although skim dependent (topology dependence)

 Still too much rejection in FH part need to be investigate  Peaks are due to –Overpopulated cells –Cell with noise problem –strange regions ? Cells effect close to the beam

Effect on EM clusters data/MC sets  Zee picked sample p evts (not used) –Filename : /rooms/living/varnes/scratch/cab/zee-p13/*/tmbfile  Zee Monte Carlo p evts –Project name ctf_p13.08_zee_sig2.5_tmb –Filename : tmb-x _CTF z-ee_np_mcp13_hepfm007.uta.edu_null_*  Estimators study –At high/low energy : emstream –At low energy : J/  skim from Jan Stark (not used yet)

Effect on EM clusters Number of cells

Effect on EM clusters estimators pT<13 GeV

Effect on EMid estimators pT<13 GeV

Effect on electrons estimators pT<13 GeV

Effect on EM clusters estimators pT>13 GeV

Effect on EMid estimators pT>13 GeV

Effect on electrons estimators pT>13 GeV

T42 effects  10% more EM cluster (10,11 )  20% less above 13 GeV  15% more Emid clusters  80% more below 13GeV  11% more electrons  34% more below 13GeV

EM Efficiency & fake rates data set  DIEM15 stream of WZ skim 1.5Mevt DIEM15-WZskim-emStream-*-*.raw_p (05) under the project name Wzskim_diem NEXT TIME

Conclusion  Code run into p14 code –T42 chunk at DST level (checked) –D0note 4146 update soon  Noise cleaning –Electronic noise seems to be deleted –Pile-up problem near beam pipe remains  Get more electrons and photons  NEXT : –Fake and efficiency –More at low energy with J/  skim