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Update on the false-dead DC wire problem M. Moulson OpB 4 Feb 2005. The false-dead-wire problem. For most KLOE running, 200-600 dead DC wires in DB2 Good news: True number of dead wires is only ~100 Bad news: 2001-2002 MC contains 200-600 dead wires
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Update on the false-dead DC wire problem M. Moulson OpB 4 Feb 2005
The false-dead-wire problem • For most KLOE running, 200-600 dead DC wires in DB2 • Good news: • True number of dead wires is only ~100 • Bad news: • 2001-2002 MC contains 200-600 dead wires • 2004 data reconstructed with 200-600 wires dead • (hits deleted) • Difficult to study the effects: • Limited dynamic range in MC sample • No runs with correct number of dead wires • Should consider re-reconstructing MC files • Probably need to re-reconstruct 2004 data
The false-dead-wire problem Complete list of number of dead wires in DB by run number available from MC web page Dead DC wires in database Run number
Origin of the problem • Code to update DB2 with physmon dead-wire map strictly assumes dead-wire map applies to run most recently taken • physmon has been re-run on older runs various times wire found dead at 1 wire alive again at 8 physmon run again wire found dead at 3 physmon next run at 12 wire found alive
Related issues • Dead wire criterion in physmon • Wire declared dead if HW efficiency < 30% • Needs tuning? • Dead wires from triplet • Not examined by physmon • List of dead wires may not contain dead wires from triplet • Hardware efficiencies • DCTRIPS module not included in physmon reconstruction chain • HW efficiencies include effects of DC trips • Efficiencies probably underestimated
Diagnostics • Kmn tagging frequencies in K+K- events (PdS) • MC reconstruction with/without DCDELETE • Technical problems with re-reconstruction of clusters • VLAB efficiencies in data—2001 vs. 2004 (FN) • 2004 data reconstructed w/ DCDELETE, ~200 dead • Originally thought many more false dead wires • Quantities examined: • Hits associated to tracks • Track multiplicities • Prob. VLAB, 2 tracks/VLAB only cluster selection • No significant effects observed • Only tests effects of ~100 extra dead wires (2004) • VLAB events not most sensitive sample?
Diagnostics • Complete re-reconstruction/comparison of ppg MC • New MC reconstruction without DCDELETE • Submitted yesterday using official mcprod apparatus
Alternatives • 2004 data (reconstruction) • Probably want to reprocess • Not an immediate priority • 2001-2002 data (MC reconstruction) • 1. Re-reconstruct .mcr files • 3600 B80 days (60 days x 60 CPUs) • + time to reincorporate results in ongoing analysis • 2. Do nothing
Checklist for MC re-reconstruction • Scripting work • Fix dead-wire and HW efficiency entries in DB • Test new DB code • Adjust physmon dead-wire threshold • Ensure that physmon dead-wire list contains dead wires found in triplet • Install DCTRIPS in physmon • Re-run physmon on all 2001-2002 data • Minor upgrades planned for datarec DBV-21 • Short-term MC development work completed?
Upgrades to datarec • Pick up all changes from recent datarec versions: • Bias samples and changes to streams not simulated • kpm stream - old algorithms eliminated, new dE/dx algorithm • ksl stream - new KSTAG • Bug fixed in dE/dx integration in VTXFIN (DBV-16) • Mainly affects kpm stream: 2907 dkc DSTs < DBV-16 • s, boost values from HepDB BMOM(3) for all EvCl routines • Further changes for datarec DBV-21: • Thickness of DC wall -75 µm • Cut DC hits with drift times > 2.5 µs • Modifications to ppg streaming code
MC development: Major topics • 1. Accidental cluster rates (SM) • 2 weeks for module to delete excess clusters • 6 weeks to reprocess MC DSTs if needed • 2. Correlated noise in DC for charged kaon tracks (PDS) • Problem and solutions under study • 3. Regeneration/nuclear interactions (MA, GL) • Problem and solutions under study • 4. Energy scale calibration for EmC simulation (PG) • Problem and solutions under study • 5. DC tracking resolution (MM) • 2 months to reparameterize errors and study resolution • Need significant input for P. de Simone • 6. EmC time distribution (CG) • Report this meeting