1. Offline Status Report M. Moulson, 20 December 2001 Summary presentation for KLOE General Meeting Outline: Processing of 2001 data History of datarec executable DST production and reprocessing: Status and plans DC tracking: current problems

2. Processing of year 2001 data Reference data set: Runs 17689—23141 (17 Feb—9 Dec) 18.1G triggers, 52825 files, 49 TB raw data Reconstructible  L dt 175.4 pb -1 Total events collected: 932M Bhabhas 540M f decays est. s f = 3.1 m b 80M K L tags 59M K L crash 132M K + K - w/ vertex 45M rp tags Day of year Run Luminosity (weekly avg., m b -1 /s) Integrated luminosity (pb -1 )

3. 2001 data: acquisition statistics On surface, R DAQ stable with respect to L In reality, some dependence on L within run groups Acquisition rate (KHz) Events per m b -1 2001 date Apparent decrease with time mostly an effect of increased L Implies absolute background levels constant over long term (compare R DAQ ) Sept. startup Low background, L 891011

4. 2001 data: processing statistics CPU time per trigger (ms) 2001 date Fraction of events tracked SunIBM Significant effect on CPU from use of IBM’s Variations in fraction tracked also important Sept-Dec period: ~21 ms/trig Low background 891011 L only partially explains variations f Nov-Dec  0.5  e FILFO  36% e FILFO can be evaluated knowing L, R trig and shows same structure e FILFO  36%

5. 2001 data: output statistics 2001 date Events/ m b -1 in ksl stream ksl event size (KB) 891011 891011 Exact same trend seen in events/ m b -1 Implies significant constant bkg in ksl s ksl expected ~1 m b, Nov-Dec: 1.7 m b Effect of compression (DBV-10) clear Event size otherwise stable Not obvious, large bkg component?

6. 2001 data sets and datarec versions DBVDates  L dt pb -1 RawStreamedRetained (flt, afl, cos) MEvtTBMEvtTBMEvtTB 8 2/3-30/4 11.021305.21203.27001.9 9 4/6-30/6 17.923306.21704.68102.5 10 11/6-31/10 81.6890024.479011.4325010.5 11 31/10-7/12 59.7409011.55607.917005.7 None 17/2-9/12 5.36601.7---- Total2001175.41810049164027646021 Streaming ~10% of total events (half of which Bhabhas) Size of datarec output  size of raw data Size of physics events  half size of datarec output 97% of good luminosity processed

7. Reconstruction issues DBVRecoveryDescription 9, 10rawCorrect SELCOS losses Filters < 11rawCorrect SPLASHFILT losses < 11DSTUpdate EMC calibrations EmC < 11DSTRun EMCSMOOTH AllrawRe-stream K + K - events (new kpm definition) kpm < 11flt New K L  p 0 p 0, K L  gg tags ksl Allflt New K S  p + p - p 0 tag 10, 11fltCorrect definition of neutral cluster for K L crash (TCA) 8, 9flt Widen b * cuts for K L crash AllfltEliminate cosmic/column cut for K L crash Allflt Widen track-mass cut to include mmg events in ppg selection rad < 11rawRe-stream neutral events in rad stream (new filter, affects FILFO) AllDST?Reduce output volume General AllDST?Reject bad events (DC trips, etc.) on basis of EVCL bits AllDST?Update luminosity estimate, run statistics, etc.

8. Reprocessing plans New kpm selection algorithms imply complete reprocessing from raw Use this opportunity to remedy all known problems with earlier reconstructions Complete reconstruction will take ~4 months Start date: 10 Jan 2002 Finish date: earlier of 10 May 2002 New data in earnest Data SetGEvtsDays DBV-82.114 DBV-92.315 DBV-108.959 DBV-114.127 All 200118.1120 Total CPU bandwidth: 2670 Hz 56 IBM CPU’s available, 21 ms/trigger Total bandwidth to/from tape: 5000 Hz Data rate in DST pass: 4.5 MB/sec per drive Average input event size: 2.7 KB Input/output volumes approximately equal: assume 3 drives Mean event processing rate: 1740 Hz

9. DST specifications Compressed YBOS format Contain subset of banks and event tags essential to analysis Raw banks dropped after initial period of debugging Produced from datarec output (at least initially) Separate jobs for kpm, ksl, rpi, rad streams One output DST per run and stream Exception: rad stream (separate charged and neutral DST’s) Fully integrated into run database DST files accessed via KID, show up in list_datarecs, etc. NFS-mounted recall areas for analysis Substantial fraction of DST output available on disk at any given time

10. DST bank list BankDescriptionNotes LRID, EVCLEvent headers T0GLGlobal t 0 TDSTTrigger summaryEssential information from TPIE, TMON, TCAF CTRGSector-to-cluster CSPSCalorimeter hitsReplaces CELE, CWRK CPLS, CLLSCalorimeter clustersCLUO exists but not significantly advantageous QCAE, QWRKQCAL hits DCNHDC hit countsDCHD, DTCE, DHRE, DPRS, DHSP dropped DTFSFitted tracksBanks shortened; hit lists dropped DVFSFitted vertices TCLOTrack-to-cluster ECLS, ECLOEvent classification KNVO, VNVO, INVONeutral vertices KeyUsed as isModified for DST’sCreated for DST’sNew, not only for DST’s

11. DST details: ksl stream KSTAG rejection to reduce stream volume Complete calorimeter reconstruction (including TCA) Update calibrations (not needed for DBV-11) Preferable anyway avoid problems in setting global T 0 Tracking: Bhabha overlaps not a problem Events tracked as Bhabhas are essentially Bhabhas T 0 step 1 redone for KLTAG’s with T RF = 5.4 ns Diagnostic histograms filled, DB2 updated SELCOS, SPLASHFILT recovery (DBV < 11) Raw data processed with DBV-10 filters negated

12. DST details: rad stream Two output DST’s: drn (NRFILT) drc (PPFILT, PPGTAG) Tracking: 60% of rad events have DTFS for Bhabhas Hit addition, multiple scattering, kink finder disabled These events completely retracked Complete calorimeter reconstruction (including TCA) T 0 step 1 redone for NRFILT events using dedicated algorithm Diagnostic histograms filled, DB2 updated NRFILT, SELCOS, SPLASHFILT recovery for DBV < 11 Raw data processed with DBV-10 filters negated NRFILT has interface with FILFO, recovery from raw

13. DST status ksl stream: dk0 DBV-11 (60 pb -1 ) completed 10-18 December Processing speed: 0.9 pb -1 /hour 7 IBM+11 Sun CPU’s, 4 drives (14 MB/sec total) Approximate output size: 3 MB/nb -1 Excludes raw banks 600 GB for all 200 pb -1 Raw banks retained first few pb -1 and double output size rad stream: drn, drc DBV-11 completed (?) 18 December to today Processing speed: 1.2 pb -1 /hour Fewer input events, more CPU/event due to tracking Approximate output size: 3.8 MB/nb -1, including raw Raw banks retained first 9 pb -1

14. Plans for DST production DBV-11: 60 pb -1 Produce DST’s for rpi stream: d3p, very similar to drc DBV-10: 82 pb -1 Produce DST’s for ksl, rad, rpi streams More complicated because of need to recover events from raw DBV-8 & DBV-9: 29 pb -1 Wait for general reprocessing Ready to begin DST production à la DBV-10 if reprocessing delayed beyond 10 Jan 2002 DST’s currently archived on tape Request NFS-mounted dedicated recall areas to be ready by mid-Jan 2002

15. DC tracking: hit inefficiencies Number of hits assigned to tracks in Bhabha events shows dropouts every 30  in track azimuth ( f ) Effect has been present from the very beginning f (rad) Hits/track ElectronsPositrons f (rad)

16. Hit inefficiency diagnostics Lost hits are actually rejected by hit-rejection algorithm e  tracks in Bhabha events affected in both MC and data p  from K S  p + p - not affected (neither MC nor data) Rejected hits, y vs. x (cm) Bhabha (data)Bhabha (MC) K S  p + p - (data)

17. Hit rejection and the L/R ambiguity Periodic effect in f presumably due to alignment of wires Bhabha tracks monochromatic, small curvature: correlation between f and wire crossing points Effect not present in MC when correct hit lists and L/R resolutions used Drift Distance, Recom (cm) Drift Distance, MC (cm) Rejected due to incorrect L/R resolutions Normally rejected on basis of residuals Rejected hits, Bhabha events Incorrect L/R causes hits to be dropped on many consecutive layers Example Bhabha event (MC) x (cm) y (cm)

18. Bhabha hit inefficiencies and luminosity Effect on luminosity estimate expected to be negligible: No evidence of modulation in f of Bhabha tracking efficiency Bhabha tracking efficiency 99.9% for 50  < q < 130  Some concern about accuracy of track parameters (z?) Effect is present in MC, and therefore taken into account d p(Recon-MC) (MeV) f (rad)

19. Bhabha hit inefficiency: solutions Improvement of PR algorithm “New” algorithm for estimation of track parameters allows L/R assignments to be redetermined Under test Improvement of hit-flipping algorithm in track-fit code Cannot correct L/R when many hits need flipping simultaneously Add capacity to look at global solutions

20. Conclusions 175 pb -1 of 2001 data processed to 97% completion DBV-11 DST’s (60 pb -1 ) essentially ready Can produce DST’s for each stream at ~1 pb -1 /hour DBV-12 reconstruction to start 10 Jan 2002 Resolution of L/R ambiguity in PR/TF under study