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 K  mn 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) 4. Energy scale calibration for EmC simulation (PG) 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