CalTask Force Workshop VLIMANT Jean-RochLPNHE10 feb 2003 T42 algorithm dedicated webpage :  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 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

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 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  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_ _mrg_ raw_p –MET test (sophie) 1000 evts of  recoT_all_ _mrg_ raw_p output : /work/coco-clued0/vlimant/TK2/runsophie/Recoanalyze.root –W, Z tests (WZ) evts of  WZskim-emStream-*-*.raw_p under the project name WZstreamTMBp13.04

Population report overall result for evts processing (WZ) Before 1815 After 1265 At second(4) 840 At first(0) 1815

Population report Region 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 changes

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

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