TASK C –Muon Detection and PID in BaBar and SiD

1. Ongoing major commitment Muon RPC detector (IFR) Henry Band –system manager Muon selectors, NN & Bagged decision tree - K.Flood, C. Vuosalo Maintaining performance Hardware Avalanche mode conversion, RPC aging,Gas humidity, Backward upgrades, backgrounds Software NN training, BDT deployment FY07, 08 running Endcap RPCs are ~40% of solid angle Expect to double data set SiD Design Study for ILC Muon Detector co-convener (Band) “Prototype” RPC design Muon Simulation R&D plan Optimize # of layers & segmentation RPC R&D Aging mechanisms Front-end electronics Alternate RPCs (glass, BESIII) Test stand TASK C –Muon Detection and PID in BaBar and SiD HenryBand - U. of Wisconsin -Task C

2. BaBar RPC Muon Detector Monte Carlo • High rate problems areas for BaBar Forward Endcap not covered by Belle Forward Barrel Backward HenryBand - U. of Wisconsin -Task C

3. Data from Nov.02 – Aug. 06 (Runs 3,4, 5a,5b) HV on ~1000 days Many new chambers show a systematic increase in current & rates correlated with position and noise rate. Others are stable Small number of RPCs have gas or HV problems (6%) Rates, currents, efficiency, temperature, humidity and gas flow monitored and recorded Shield wall + local lead added for Run 5 12 RPC HV modules per layer, grouped into 6 gas volumes Signal and background rates vary widely with position West East 6 5 4 3 2 1 Forward RPCs L Days Gas flow High rate around beamline in inner layers >20 Hz cm2 HenryBand - U. of Wisconsin -Task C

4. 4 ½ month access for LST Replace remaining 4 sextants of Barrel RPCs with LST chambers All Forward endcap DAQ(>1000), HV, and Gas lines disconnected and reconnected Areas of concern High rates in inner layers around beam pipe Humidity Old Backward infrastructure More concerns Backgrounds rising with luminosity High rate in outermost layers Responses Convert 12 Forward RPCs to avalanche mode New preamps Gas mixing system Upgrade Backward endcap HV and gas distribution Install missing shielding wall components Continue gas studies RPC Run 6 activities HenryBand - U. of Wisconsin -Task C

5. During Runs 3-4 Found inefficient regions near gas inlets Outer layers inefficient in Run 5 But OK with cosmics Input IFR gas ~0% RH RPC exhaust ~30% RH Humidify input gas to 35% for some and later all in Run 5b Clear improvements seen Stable efficiency in Run 6 Gas Humidity Run 53918 April, 05 Run 57387 Aug. 23, 05 HenryBand - U. of Wisconsin -Task C

6. Declining efficiency observed in high rate ring at small radii Most aging processes proportional to integrated charge Accumulated charge in the high rate ring (>600 mC/cm2) would likely damage the RPC graphite Convert to avalanche mode Lower current, improved efficiency 22% Ar, 72.9% C2H2F4,4.5% C4H10, 0.6%SF6 @9200 V 12 middle RPCs converted for Run6 – Princeton, Ferrara, Wisconsin Improved efficiencies, lowered currents, noise rates +20% Avalanche Mode Feb. 2003 Oct. 2003 Dec. 2003 Jan. 2004 Jun. 2004 Jun. 2005 Avalanche mode Streamer mode HenryBand - U. of Wisconsin -Task C

7. With shielding wall and PEP trickle injection was able to run layers 15&16 for the first time in Run 5 Estimate at end of Run 5a Scale highest module rates to 20 1033 Layer 12 ~ 5.6 kHz  18 kHz Layer 14 ~ 13 kHz  39 kHz Layer 15 ~ 40 kHz  120 kHz Concluded - Layer 15/16 rates OK for now may need to add snout Backgrounds increased significantly at the end of Run 5b Projected rates - too high The snout installed last week Outer Layers mA days • Layer 12  26 kHz • Layer 14  51 kHz • Layer 15  220 kHz Layer 15 mA days HenryBand - U. of Wisconsin -Task C

8. Fluorine studies Streamer 1.42 ± 0.11 mmol /C • Several studies have shown correlation between the production of F- and increased currents and surface damage • F- in the exhaust gas measured by bubbling gas through a H2O &TISAB solution and measured with a Fluorine specific probe • Comparison of avalanche mode and streamer mode RPCs shows comparable F- production • Avalanche Current is ~ ¼ streamer mode • Avalanche produces more F- per unit charge Avalanche 3.82 ± 0.23 mmol /C HenryBand - U. of Wisconsin -Task C

9. Wisconsin developed muon NN selector now used by almost all BaBar analyses Significant improvements over cut based selector Improvements to hardware improve selector performance 2002 upgrade Shielding wall LST Further improvements LST will increase barrel ID efficiency by 10-20% Decision tree algorithm will better utilize EMC information improving performance in 2000-6 RPC barrel BaBar Muon PID Improved Performance HenryBand - U. of Wisconsin -Task C

10. Very Tight Very Tight Very Tight Fake Rate Very Tight Fake Rate Very Loose Very Loose Fake Rate Very Loose Fake Rate Very Loose Loose Loose Loose Fake Rate Loose Fake Rate Tight Fake Rate Tight Tight Tight Fake Rate BaggedDecisionTree vs. NN Performance Comparison • Further improvements • Decision tree algorithm will better utilize EMC info, dedx from DCH and VXD. Improving performance in 2000-6 RPC barrel. • Small improvements for Forward endcap and LST barrel • 10-20% reduction in pion efficiency for same muon efficiency • 1-10% gain in muon efficiency for same pion efficiency HenryBand - U. of Wisconsin -Task C

11. Endcap Sectors 1 2 3 4 5 6 Ongoing Muon PID Tasks • Training NN for Run 6 (with LST) • Integrating StatPatternRecognition into BaBar software environment. • Adding Muon BDT to BaBar Particle ID. • Is it possible to improve more? • Study of other possible performance enhancements for last reprocessing of all BaBar data • Adaptive Kalman filter cluster reconstruction • Noise rates differ by at least 100 in different regions of the IFR HenryBand - U. of Wisconsin -Task C

12. ILC Muon Detector R&D FY07 FY08 FY09 FY10 FY11 • Design effort started to produce a ILC detector TDR by 2010 (same as GDE machine) • Wisconsin group using its BaBar expertise to play an important role in design of the muon system • First part - generic studies of detector requirements,detector independent optimization of geometry, muon ID algorithms • Second part - Develop RPC design with risk assessments and cost analysis so that a technology choice can be made within the year. SiD CDR, Muon Technology choice Detector downselect 4-->2 TDR HenryBand - U. of Wisconsin -Task C

13. Despite Babar experience RPCs are good match to ILC environment Cost advantage 2nd generation RPCs have been reliable at low rates Avalanche mode ILC muon detector Modest resolution Low backgrounds Can be met many detector technologies Scintillator strips RPCs Generic Detector studies Tail-catcher? # layers? Resolution? Specific designs Steel geometry Maximize coverage Muon particle ID in Hcal/muon SiD – ILC Detector Concept Study HenryBand - U. of Wisconsin -Task C

14. Barrel Size ~2.9X5.9 - 5.6X5.9 m With (15 layers) 10 RPCs per layer per octant for a total of 1200 RPCs in the barrel with area of ~ 2700 m2. Endcaps 3 RPCs per octant per layer the endcaps would have 720 RPCs with a area of 3400 m2. 6100 m2 (15 layers) - 2600 chambers @ 2-3 m2 350,000 channels RPCs 3 cm pitch ~ 1cm resolution XY readout To avoid cabling over RPC boundaries assumed 1 KPIX chip per side - 5200 SiD RPC Details HenryBand - U. of Wisconsin -Task C

15. Despite BaBar experience both Atlas and CMS have large muon systems using Bakelite RPCs with linseed oil as trigger chambers Extensive R&D Avalanche mode Improved graphite layers Humidified gas Aging tests to 10 LHC year equivalents 2nd generation BaBar RPCs >10 Hz/cm2 losing efficiency < 1 Hz/cm2 few problems in 5 years Belle glass RPCs doing well when not rate limited > 0.2 Hz cm2 BES III and Daya Bay will use Bakelite surfaced with special plastic film - no linseed oil RPC Aging HenryBand - U. of Wisconsin -Task C

16. Tests of front end electronics Test KPIX chip with RPCs Test Argonne/CALICE chip Characterize RPCs BESIII style bakelite RPCs Glass RPCs – may be used in SiD hadron calorimeter Study aging mechanisms Fluorine production in RPC gas Fluorine absorption by chamber surfaces Refurbish Wisconsin cosmic ray test stand Use Babar spare RPCs Existing Wisconsin ADCs/latches Upgrade VME to PCI adapter VME crate Fluorine probes/meters Gas circulation pumps SiD – RPC Studies HenryBand - U. of Wisconsin -Task C

17. Final mods to IFR hardware nearly complete Switch to maintenance mode Continue aging studies Ready for higher luminosity (bring it on!) LST barrel improves overall NN muon selector performance BDT muon selector will further improve efficiency in Run 1-5 data Further optimization of muon selectors under study Aggressive ILC detector R&D can lead to detector TDRs by 2010 if well supported Muon effort Generic design study to optimize # layers, resolution Develop RPC option Overall design, costs, & performance Evaluate specific electronic designs Aging studies Evaluate specific RPC designs(BesIII) Summary HenryBand - U. of Wisconsin -Task C