# Presentation: 812096

## CalTask Force Workshop

- VLIMANT Jean-Roch		LPNHE		10 feb 2003

- _T42 algorithm_
- dedicated webpage :http://www-d0.fnal.gov/~vlimant/noise-suppdescr/Description.html

- Principale
- Implementation
- Effect on data
- To come

## T42Principale : reject isolated medium cellsNamed after an algorithm used in H1

- Select high signal cells (4 sigma)
- Keep their significant neighbours (2 sigma)
- Thresholds to be tuned

##  cal_t42 Packageusing same frame as cal_nada

-  cal_t42 Packageusing same frame as cal_nada

- Classes :
- Calt42 : container for cell lists
- Calt42Chunk : container for Calt42 object
- Calt42Reco :
- does the cleaning and chunks managment.
- Get the neighbourhood info from a Calt42Struct object which allows a linear algorithm complexity.

## Calt42Reco

## Calt42Reco

## 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 neighbours within the array
- single pointer to be assigned to a CalCell available in data
- lots of methods user-friendly
- method to read neighbourhood information from a text file (rather than doing awfull, uncheckable code)

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

- _How to check ?_
- Standalone executable return neighbours for a given cell (exist as a method)
- Check cell_files and pictures for exceptions descriptions (webpage)
- Check the code of the four executables (simple algorithms)

| Regular cells
normal
out of fine layers (3,4,5,6)
near fine layers (2,7) | Exceptions cells
Neighbours above or below splited into different layers
Intercryostat and nearby cells |
| --- | --- |

## Study effects on data

- Data sets
- Debugging (preliminary result ) with
- recoT_all_0000168619_mrg_116-143.raw_p13.04.00
- MET test (sophie) 1000 evts of
- recoT_all_0000168725_mrg_100-107.raw_p13.04.00
- output : /work/coco-clued0/vlimant/TK2/runsophie/Recoanalyze.root
- W, Z tests (WZ) 10000 evts of
- WZskim-emStream-*-*.raw_p13.04.00 under the project name WZstreamTMBp13.04

## Population reportoverall result for 10000 evts processing (WZ)http://www-d0.fnal.gov/~vlimant/noise-suppps/WZ_plots/Pop_report_10000_WZ.ps

- Population reportoverall result for 10000 evts processing (WZ)http://www-d0.fnal.gov/~vlimant/noise-suppps/WZ_plots/Pop_report_10000_WZ.ps

- Before1815

- After1265

- At second(4)840

- At first(0)1815

## Population reportRegion result

## Population reportRegion result

- Population reportRegion result

- Isolated cells

- Clustered cells

## Isolation decreases and tightens by 10%
EM fraction tightens by 25%
Hmatrix8 decrease by 5% 
EMIds increases by 10%

- EM fraction tightens by 25%
- Hmatrix8 decrease by 5%
******EMIds increases by 10%**

- EM changes

## before

- after

## before

- after

## before

- after

## MET changes

**	********W transverse mass with more entries**
- MEx centered (- 30%)
- MEx made more even
******fewer noise**

## before

- after

## before

- after

## T42 conclusions Remains to do

- Ultimatetly cross check neighbours
- Study thresholds for reasonnable loss of cells
- More studies on effect on physics
- Rootuple with dedicated data block available, help is welcome