Overview of SuperB Particle identification, and work towards the TDR E.A.Kravchenko on behalf PID group

Outline Introduction Baseline PID Optional PID DIRC upgrade Optional PID DIRC with time-walk chromaticity correction Forward PID TOF system Focusing Aerogel RICH Backward PID – TOF system R@D tasks and activities MC study of physics requirements on PID acceptance Test beams and other Conclusion

Introduction The list of Institutes involved in PID: SLAC group B, University of Hawaii, University of Cincinnati, Slovenia, Novosibirsk, INFN Padova Questions: Physics!!! Money Forward (+Backward) PID? Pros => extra PID efficiency, larger coverage, momentum measurement improvement, … Contra => space, material in front of the EMC, hermeticity(?) money… MC studies =>

SuperB detector PID system(s) BASELINE: DIRC upgrade => PMTs replacement + fast new electronics (1.5 ns or 200 ps timing resolution) OPTIONS: DIRC with time-walk chromaticity correction => small stand-alone box, fast pixel PMTs Forward PID TOF system Focusing Aerogel RICH Backward PID => TOF system

DIRC prototype beam test SLAC 10 GeV/c electron beam in End Station A Beam enters bar at 90º angle Prototype is movable to 7 beam positions along bar Time start from the LINAC RF signal, but correctable with a local START counter SLAC-built amplifier and constant fraction discriminator TDC is Phillips 7186 (25ps/count), CAMAC readout Beam spot: s < 1mm Lead glass: Local START time: s ~36ps

Time-walk chromaticity correction with DIRC prototype All pixels: Expected performance of a final device: Correction off: Correction on: σ=10.4mrad σ=6.9mrad θc (mrad) θc (mrad) The method works! Next steps: PMT optimization => SLAC Electronics design => Hawaii Design and optimizing of compact focusing system => Cincinnati θc resolution (mrad) Photon path length (m)

TOF test setup with two MCP-PMTs Control unit PiLas 635 nm Npe ~ 50 2.33 kV 400 ps/div 10 mV/div Laser diode MCP_start Ortec 9327 Amp/CFD Fiber splitter MCP_stop Ortec 9327 Amp/CFD Running conditions: 1) Low MCP gain operation (<105) !!! 2) Linear operation 3) CFD discriminator 4) No additional ADC correction TAC 566 START ADC 114 STOP

TOF, results with the laser diode Two Burle/Photonis MCP-PMTs with 10 mm MCP holes. Ortec 9327Amp/CFD & TAC566 & 14 bit ADC114 (Electronics calibration: s Pulser + TAC_ADC + Amp/CFD ~ 3.42 ps) Two detector resolution (Npe ~ 50 pe each): ADC [counts] single detector ~ (1/√2) s double detector ~ 7.2 ps s ~ 10.2 ps ADC [counts] The expected resolution for the TOF is ~20 ps. The main contribution is 13 ps ‘start’ time spread and we expect others.

Focusing aerogel RICH concept Objective: to reduce thickness contribution Single ring focusing P. Križan, “Aerogel RICH”, Talk at Super B Factory Workshop, Jan 2004, Hawaii

Layout of the FARICH in the SuperB detector

FARICH expected performance 420 Burle type MCP PMT 4.3 mm pad size, 28x28 matrix 60480 channels 4-layer aerogel radiator, 40 mm thickness FARICH momentum resolution TOF PID with FARICH at low momentum. Test beam measurement στ~100 ps (Slovenia group results)

Forward TOF and FARICH comparison Pro Contra Much better π/K,μ/π,e/π identification Momentum measurement improvement in the forward Better background endurance 15 cm of additional space 10 times more channels Price (?) The amount of material is almost the same

MC study of physics requirements on PID acceptance Full B-meson reconstruction. Only PID geometry efficiency 18 B-meson decay modes were used. Depending on the modes of B and D decays, forward PID increases efficiency of B reconstruction by 10-30%, forward + backward PID by 15-50%

MC study of physics requirements for PID To make the decision about forward (and backward) PID options we need to have Fast MC and compare detector efficiencies for baseline and optional PID on some ‘key’ processes. What are they? DIRC, TOF and FARICH performance will be presented in Fast MC in the form of PID tables depending on P and Θ

Test beams and other Test beam experiments are planned at SLAC at End Station A with DIRC and TOF prototypes: test of new electronics for DIRC and TOF to get <10ps timing resolution with particles Test beam at KEK with aerogel RICH (Slovenia, Novosibirsk?) Tests of DIRC focusing schemes with cosmic muons at Cincinnati …

Conclusion Look the agenda of PID I and PID II sessions for some answers and new questions. Feb 13,16:00->18:00    PID I (Convener: David Leith (SLAC) ) Location: Kavli building, 2nd floor, building 51 16:00 "Report on results from SLAC beam test of long bar, and TOF developments, (20') Jerry Vavra [SLAC] 16:30 "Compact, low-power readout: results from SLAC beam test, further improvements, and next development plans" (15') Gary Varner [Hawaii] 16:50 "Perspective on TOF R&D at Padua." (10') Roberto Strolli [Padua] 17:05 Discussion on the barrel PID systrem for TDR - R&D, MC studies, hurdles and process". (40') General discussion, with brief introductions by David Leith and Alan Schwartz 17:45 "Report from Superb Computing group activities , and plans ". (15') Jochen Schwiening [SLAC]

Conclusion (continued) 09:00->10:30    PID II (Convener: David Leith (SLAC)) Location: Kavli building, 2nd floor, building 51 09:00 "Report on hardware tests, MC studies, next steps and activities towards the TDR, at Ljublana". (12') Peter Krizan [Ljublana] 09:17 "Report on hardware tests, MC studies, next steps and activities towards the TDR, at BINP". (12') Evgeniy Kravchenko [BINP, Novosibirsk] 09:34 "Summary of availability of test beams around the world". (10') Jerry VaVra (SLAC) 09:50 "General Discussion on the End Cap PID systems for the Superb TDR - R&D, MC studies, hurdles and the process". (40') General discussion, following some overview comments by David Leith

Backup slides B-meson full reconstruction geometry efficiency