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

2. 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
tasks and activities
MC study of physics requirements on PID acceptance
Test beams and other
Conclusion

3. 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 =>

4. 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

5. 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

6. 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)

7. 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

8. 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.

9. 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

10. Layout of the FARICH in the SuperB detector

11. 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)

12. 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

13. 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%

14. 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

15. 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 …

16. 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]

17. 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

18. Backup slides B-meson full reconstruction geometry efficiency