VLIMANT Jean-Roch LPNHE 13 may 2003 CAT plenary meeting T42 algorithm dedicated webpage : http://www-d0.fnal.gov/~vlimant/noise-suppdescr/Description.html T42 + Top_analyze +d0root_analysis Principle & Implementation Effect on cells Effect on EM objects VLIMANT Jean-Roch LPNHE 13 may 2003

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 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 ) + 1088( 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 http://www-d0. fnal 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 How to check ? Trust me WebPage : check rules and pictures Calt42Struct::PrintNeighbours(ieta,iphi,layer) Calorimeter display : to be written

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 = < cal_t42 Calt42> // process the t42 algo or T42 = < cal_t42 Calt42Combine> // 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 10000 evts of WZskim-emStream-*-*.raw_p13.06.01 under the project name WZstreamTMBp13.06 Unstreamed data 10000 evts in files recoT_all_0000174234_mrg_*-*.raw_p14.01.00 Global_CMT run Min/Zero bias Wzskim 10000 evts of Wzskim-mzbiasStream-*-*.raw_p13.06.01 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 33-37 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)

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

Effect on EM clusters data/MC sets Zee picked sample p13.05 2418 evts (not used) Filename : /rooms/living/varnes/scratch/cab/zee-p13/*/tmbfile Zee Monte Carlo p13.08 6000 evts Project name ctf_p13.08_zee_sig2.5_tmb Filename : tmb-x13.08.00_CTF13.08.00-02-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 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 ) 15% more Emid clusters 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_p13.06.01 (05) under the project name Wzskim_diem NEXT TIME

Conclusion Code run into p14 code Noise cleaning 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