DOE REVIEW TASK C Aug. 21-22, 2006 * WORK AT SLAC – Babar & ILC

1. DOE REVIEW TASK C Aug. 21-22, 2006 * WORK AT SLAC – Babar & ILC R. Prepost Faculty S. Dasu Faculty H. Band Senior Scientist K. Flood PostDoc M. Pierini PostDoc Students J. Hollar Graduates 8/06 C. Vuosalo Started 6/06 * R. Prepost Presentation R. Prepost

2. BaBar Physics Analysis BaBar System Work IFR Muon System Management BaBar Particle ID Muon ID/Neural Net Development ILC Polarized Photocathode R&D Source Laser Development SiD Muon System KPIX ADC IC Testing Task Activities R. Prepost

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4. ICHEP08 Double again from 2006 to 2008 • PEP-II: 9xIR-2 vacuum chambers (including 2xnew Q1/Q2 bellows), 2xrf stations, BPM work, feedback systems • BABAR: LST installation Double from 2004 to 2006 ICHEP06 4-month down for LCLS, PEP-II & BABAR Projected data sample growth 20 Integrated Luminosity [fb-1] 17 12 Lpeak = 9x1033 R. Prepost

5. Babar AnalysesCompleted Theses R. Prepost

6. Babar AnalysesCurrent Analyses R. Prepost

7. Constraints to CKM Triangle from Vtd/Vts Limits. (From Thesis of P. Tan) R. Prepost

8. Status of the Unitarity Triangle by Utfit collaboration R. Prepost

9. ICHEP06: CBd = 1.25 ± 0.43 fBd = (-2.9 ± 2.0)o Sensitivity to New Physics in B mixing for different size data sets. DmBdEXP = CBdDmBdSM ACP(J/yK0) = sin (2(b + fBd)) Now CBd =1 and fBd=0 in the Standard Model extrapolation to BaBar+Belle final sample(~2008) extrapolation to 10 ab-1 of SuperB factory 08 Super B R. Prepost

10. RPC Management RPC Studies and Gas Chemistry Forward EndCap Upgrade RPC Operations – Band and Students BaBar System Work - Band BaBar Particle ID –Flood/Hollar/Band • Muon Identification R. Prepost

11. Near Term Plans 2006-2007 (Analyses using 400 fb–1) • Complete D mixing analysis • Use complete dataset through 2006 (K. Flood) • Complete b  s l+ l– analysis including asymmetries • Improvements from NN m ID and reconstruction of several Xs final states, much like in Eichenbaum b  s analysis (K. Flood) • Continue Global analysis of CKM parameters • Add new results from BaBar and Belle (M. Pierini) • Time dependent CP asymmetries • Update of B  K K K analyses (M. Pierini) • Update of B  K 0 analysis (M. Pierini) • New study of B  K +– analysis (M. Pierini) • Rare decays • Finish B  l+l– analysis (M. Pierini) • Recoil technique to study difficult rare decays (C. Vuosalo) • Improve the technique to study, e.g., B  K and B  K  R. Prepost

12. Long Term Plans 2006-2008 (Analyses using 1 ab–1) • Exclusive B  K*g & semi-inclusive b  sg • ACP and DI measurements continue to be sensitive • Semi-inclusive b  s l+ l – • Improve ACP and forward-backward asymmetry zero-crossing point • B  rg / B  K*g • Improve Vtd/Vts to compete with mixing measurement • Measure CKM parameters in rare decays • Continue to probe for deviations from Standard Model • Recoil method • Fully reconstruct one B to reduce backgrounds • Reduced signal statistics compensated by improved systematics • Access to rare decays with neutrinos, Knn, Ktt … • Cleaner samples of inclusive decays of the other B • Lepton flavor violating  decays • Similar to the recoil method R. Prepost

13. Papers • EichenbaumPRL 93, 21804 (2004); PRD 72, 052004 (2005). • Ping/DasuPRD 70, 112006 (2004); PRL 94, 011801 (2005). • HollarLepton Photon 05 Paper; PRD 73, 092001(2006). • Band (IFR) NIM A552, 27 (2005); NIM A539, 155 (2005); NIM A538, 801 (2005). • Prepost Appl. Phys Lett. 85, 2640 (2004). • Pierini JHEP 0603, 080 (2006); PRD 72, 051103 (2005); PRD 71, 111102 (2005); PRL 95, 011801 (2005). R. Prepost

14. TALKS Conference Presentations 05-06 R. Prepost

15. TALKS (Continued) R. Prepost

16. ILC Polarized Source • Proposal to LC Accelerator R&D at Universities. Awards FY05 and FY06 of $34.6k/FY • Budget for X-Ray Analysis, SIMS Analyses and Photoluminescence Hardware. • Group expands effort to include full electron polarized source system. R. Prepost

17. Components of Polarized Source R&D • Source Laser R&D • Photocathode Structures • Measurement of Photocathode Spin Relaxation Times: Faraday Rotation (new experiment & setup) R. Prepost

18. Polarized Source R&D Program R. Prepost

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20. Source Laser Block Diagram Wisconsin Hardware Pockels Cell & Amplifier R. Prepost

21. Wisconsin Hardware R. Prepost

22. New SBIR with SVT Associates • Completed 2002 Phase 2 SBIR Study of GaAs/GaAsP Superlattice. • Submitted new Phase 1 SBIR for Study of GaAs/InGaP Superlattice. Approved 2005. “Highly Polarized Photocathodes Via Minimization of Spin Relaxation InGaP has lower spin relaxation than GaAsP: expect reduced depolarization. Also expect Quantum Efficiency Enhancement. R. Prepost

23. SVT SBIR Phase I Structures GaAs/InGaP strained superlattice

24. Three structures with 1.25% lattice mismatch Ec (eV) HH LH Ev (eV) Strained wells Strained wells Strained barriers R. Prepost

25. Strained wells 1) 5 nm GaAs cap Be: 1x10^19 2) 4 nm In(0.32)Ga(0.68)P Be: 1x10^17 3) 4 nm GaAs Be: 1x10^17 repeat 2) and 3) 12 times 4) 2.5 um In(0.32)Ga(0.68)P Be: 5x10^18 5) 2.5 um In(x)Ga(1-x)P x=0.48 -> 0.32 Be: 5x10^18 6) In(0.48)Ga(0.52)P buffer lattice-matched to GaAs 7) GaAs substrate Strained Barriers 1) 5 nm GaAs cap Be: 1x10^19 2) 4 nm In(0.65)Ga(0.35)P Be: 1x10^17 3) 4 nm GaAs Be: 1x10^17 repeat 2) and 3) 12 times 4) 1 um Al(0.3)Ga(0.7)As Be: 5x10^18 5) GaAs buffer 6) GaAs substrate Structures • = 767 nm Ehh-lh = 109 meV • = 832 nm Ehh-lh = 62 meV R. Prepost

26. SVT SBIR Phase-I Wafers Three wafers have been grown. • II) Strained barrier – SVT-3031 • 1) 5 nm GaAs cap Be: 1x10^19 • 2) 4 nm In(0.65)Ga(0.35)P Be: 1x10^17 • 3) 1.5 nm GaAs Be: 1x10^17 • repeat 2) and 3) 18 times • 4) 1 um Al(0.3)Ga(0.7)As Be: 5x10^18 • 5) GaAs buffer • 6) GaAs substrate • I) Strained wells – SVT-3039 • 1) 5 nm GaAs cap Be: 1x10^19 • 2) 4 nm In(0.31)Ga(0.69)P Be: 1x10^17 • 3) 4 nm GaAs Be: 1x10^17 • repeat 2) and 3) 12 times • 4) 2.5 um In(0.31)Ga(0.69)P Be: 5x10^18 • 5) 2.5 um In(x)Ga(1-x)P x=0.48 -> 0.31 Be: 5x10^18 • 6) In(0.48)Ga(0.52)P buffer lattice-matched to GaAs • 7) GaAs substrate SVT-3017 1.5 nm In(0.65)Ga(0.35)P 4 nm GaAs R. Prepost

27. Polarization and QE SVT-3039 First Measurements Will re-measure all three samples. Will X-ray all three samples. R. Prepost

28. Faraday Effect Rotation to Measure Spin Relaxation Times • Prepare Pump/Probe Laser Pulses with Variable Probe Delay Time. • Pump with Circularly Polarized Light to Create Polarized Electrons in the Conduction Band. • Probe with Linearly Polarized Light Laser Pulse at Time t wrt Pump. • Measure the Rotation Angle of the Linear Polarization as a Function of time t. The Rotation Angle is Proportional to the Polarization. • A Series of Measurements will give P(t) and thus the Relaxation t. • Requires a laser with femtosecond pulses to be able to measure picosecond values of t. R. Prepost

29. Status of Faraday Rotation Experiment • Femtosec laser to be delivered to Wisconsin on Sep. 1. The laser will be tested at Wisconsin. • 480 V power and AC crash buttons installed. Argon Ion laser can be operated. • Fieguth, Bower, and Schmerge came to the lab on Aug. 10 to go over the SOP and laser safety issues. • Interlock switches need to be installed. • New goggles to be purchased. • SOP to be revised. • Shooting for a laser safety approval in mid September. R. Prepost

30. Faraday Rotation Laser R. Prepost