1. CalTask Force Workshop VLIMANT Jean-RochLPNHE10 feb 2003 T42 algorithm dedicated webpage : http://www-d0.fnal.gov/~vlimant/noise-suppdescr/Description.html  Principale  Implementation  Effect on data  To come

2. 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

3. cal_t42 Package using 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.

4. Calt42Reco

6. 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)

7. 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

8. 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

9. Population report overall result for 10000 evts processing (WZ) http://www-d0.fnal.gov/~vlimant/noise-suppps/WZ_plots/Pop_report_10000_WZ.ps Before 1815 After 1265 At second(4) 840 At first(0) 1815

10. Population report Region result

11. Isolated cells Clustered cells

12.  Isolation decreases and tightens by 10%  EM fraction tightens by 25%  Hmatrix8 decrease by 5%  EMIds increases by 10% EM changes

16.  MET increase (in mean)  W transverse mass with more entries  MEx centered (- 30%)  MEx made more even  fewer noise MET changes

19. 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