DOE 8/21-22/06R. Prepost1 DOE REVIEW TASK C Aug , 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

DOE 8/21-22/06R. Prepost2 Task Activities 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

DOE 8/21-22/06R. Prepost3

DOE 8/21-22/06R. Prepost4 Projected data sample growth Integrated Luminosity [fb -1 ] L peak = 9x10 33 oPEP-II: 9xIR-2 vacuum chambers (including 2xnew Q1/Q2 bellows), 2xrf stations, BPM work, feedback systems oBABAR: LST installation 4-month down for LCLS, PEP-II & BABAR Double from 2004 to 2006 ICHEP06 Double again from 2006 to 2008 ICHEP08

DOE 8/21-22/06R. Prepost5 Babar Analyses Completed Theses

DOE 8/21-22/06R. Prepost6 Babar Analyses Current Analyses

DOE 8/21-22/06R. Prepost7 Constraints to CKM Triangle from V td /V ts Limits. (From Thesis of P. Tan)

DOE 8/21-22/06R. Prepost8 Status of the Unitarity Triangle by Utfit collaboration

DOE 8/21-22/06R. Prepost9 Sensitivity to New Physics in B mixing for different size data sets.  m Bd EXP = C Bd  m Bd SM A CP (J/  K 0 ) = sin (2(  +  Bd )) extrapolation to BaBar+Belle final sample(~2008) C Bd =1 and  Bd =0 in the Standard Model ICHEP06: C B d = 1.25 ± 0.43  B d = (-2.9 ± 2.0) o extrapolation to 10 ab -1 of SuperB factory Now 08Super B

DOE 8/21-22/06R. Prepost10 BaBar System Work - Band RPC Management RPC Studies and Gas Chemistry Forward EndCap Upgrade RPC Operations – Band and Students BaBar Particle ID –Flood/Hollar/Band Muon Identification

DOE 8/21-22/06R. Prepost11 Near Term Plans (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  ID and reconstruction of several X s 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 

DOE 8/21-22/06R. Prepost12 Long Term Plans (Analyses using 1 ab –1 ) –Exclusive B  K*  & semi-inclusive b  s  A CP and  I measurements continue to be sensitive –Semi-inclusive b  s l + l – Improve A CP and forward-backward asymmetry zero-crossing point –B   / B  K*  Improve V td /V ts 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, K, K  … Cleaner samples of inclusive decays of the other B –Lepton flavor violating  decays Similar to the recoil method

DOE 8/21-22/06R. Prepost13 Papers Eichenbaum PRL 93, (2004); PRD 72, (2005). Ping/Dasu PRD 70, (2004); PRL 94, (2005). Hollar Lepton Photon 05 Paper; PRD 73, (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, (2005); PRD 71, (2005); PRL 95, (2005).

DOE 8/21-22/06R. Prepost14 TALKS Conference Presentations 05-06

DOE 8/21-22/06R. Prepost15 TALKS (Continued)

DOE 8/21-22/06R. Prepost16 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.

DOE 8/21-22/06R. Prepost17 Components of Polarized Source R&D Source Laser R&D Photocathode Structures Measurement of Photocathode Spin Relaxation Times: Faraday Rotation (new experiment & setup)

DOE 8/21-22/06R. Prepost18 Polarized Source R&D Program

DOE 8/21-22/06R. Prepost19

DOE 8/21-22/06R. Prepost20 Source Laser Block Diagram Wisconsin Hardware Pockels Cell & Amplifier

DOE 8/21-22/06R. Prepost21 Wisconsin Hardware

DOE 8/21-22/06R. Prepost22 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 “Highly Polarized Photocathodes Via Minimization of Spin Relaxation InGaP has lower spin relaxation than GaAsP: expect reduced depolarization. Also expect Quantum Efficiency Enhancement.

SVT SBIR Phase I Structures GaAs/InGaP strained superlattice

DOE 8/21-22/06R. Prepost24 Three structures with 1.25% lattice mismatch Ec (eV) Ev (eV) Strained wells Strained barriers HH LH

DOE 8/21-22/06R. Prepost25 Structures 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 = 767 nm E hh-lh = 109 meV = 832 nm E hh-lh = 62 meV

DOE 8/21-22/06R. Prepost26 SVT SBIR Phase-I Wafers I) Strained wells – SVT ) 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 II) Strained barrier – SVT ) 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 SVT nm In(0.65)Ga(0.35)P 4 nm GaAs Three wafers have been grown.

DOE 8/21-22/06R. Prepost27 Polarization and QE SVT-3039 First Measurements Will re-measure all three samples. Will X-ray all three samples.

DOE 8/21-22/06R. Prepost28 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  Requires a laser with femtosecond pulses to be able to measure picosecond values of .

DOE 8/21-22/06R. Prepost29 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.

DOE 8/21-22/06R. Prepost30 Faraday Rotation Laser