# Presentation: 408844

## CAT plenary meeting

- VLIMANT Jean-Roch		LPNHE		13 may 2003

- _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

## 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

-  cal_t42 Packagecreated 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 ) + 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

- Calt42Structuse in Calt42Reco

## Calt42StructNeighbourhood information http://www-d0.fnal.gov/~vlimant/noise-suppdescr/Description.html

- _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 = < 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

- 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 reportemstream data

## Region reportWZstream data with problems 

- Region reportWZstream data with problems

## Region reportunstreamed data

- Region reportunstreamed data

## Region reportunstreamed data with problems 

- Region reportunstreamed data with problems

## Region reportminimum/zero bias data

- Region reportminimum/zero bias data

## Region reportminimum/zero bias data with problems 

- Region reportminimum/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 ?

- 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 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 clustersNumber of cells

## Effect on EM clustersNumber of cells

- Effect on EM clustersNumber of cells

## Effect on EM clustersestimators pT<13 GeV

- Effect on EM clustersestimators pT<13 GeV

## Effect on EMidestimators pT<13 GeV

- Effect on EMidestimators pT<13 GeV

## Effect on electronsestimators pT<13 GeV

- Effect on electronsestimators pT<13 GeV

## Effect on EM clustersestimators pT>13 GeV

- Effect on EM clustersestimators pT>13 GeV

## Effect on EMidestimators pT>13 GeV

- Effect on EMidestimators pT>13 GeV

## Effect on electronsestimators pT>13 GeV

- Effect on electronsestimators 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_p13.06.01 (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