1. Update on the false-dead DC wire problem
M. Moulson
OpB 4 Feb 2005

2. The false-dead-wire problem
For most KLOE running, dead DC wires in DB2
Good news:
True number of dead wires is only ~100
Bad news:
MC contains dead wires
2004 data reconstructed with 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

3. 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

4. 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

5. 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

6. 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 (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?

7. Diagnostics Complete re-reconstruction/comparison of ppg MC
New MC reconstruction without DCDELETE
Submitted yesterday using official mcprod apparatus

8. Alternatives 2004 data (reconstruction) Probably want to reprocess
Not an immediate priority
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

9. 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 data
Minor upgrades planned for datarec DBV-21
Short-term MC development work completed?

10. 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

11. 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)
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