UCSD Participation in BaBar

1. UCSD Participation in BaBar Vivek Sharma University of California, San Diego DOE Site Review 2005

2. Luminosity !  The CP Detector at PEP-II ring BREAKING NEWS !

3. BaBar Collects 1034 Luminosity From PEP-II !! Touched 1034 instant. lumi again at 22:30, 9th Oct

4. RUN 5 RUN 4 RUN 3 RUN 2 RUN 1 Cumulative Luminosity

5. Upgrades Upgrades Detector Prepared for Higher Peak luminosity Background conditions reliably extrapolated based on beam currents & luminosity EMC 6580 CsI(Tl) crystals 1.5T solenoid e+(3.1GeV) DIRC (PID) 144 quartz bars 11000 PMs Drift Chamber 40 layers e-(9GeV) Silicon Vertex Tracker 5 layers, double sided strips Instrumented Flux Return Iron / Resistive Plate Chambers or Limited Streamer Tubes (muon / neutral hadrons) All other systems fully capable of highest luminosities

6. Now: Barrel LSTs Now: Barrel RPCs IFR Replacement of RPC with LST: Crucial Upgrade For  ID Bottom & top sextants installed summer 2004 Remaining sextants in summer 2006

7. BaBar’s Physics Productivity

8. Summary of UCSD Roles on BABAR • Commissioning Detector • Survey PEP-II machine conditions prior to BaBar installation • pull together all elements of the SVT hardware, electronics & data-acquisition software required to operate an SVT module during PEP II commissioning • Drift Chamber operations • Hardware & software systems available early 1998 for commissioning • Core online software, trigger, other system development • Participation essential for continuation of existing long-term leading role on the project • Tracking & core software development • Key element to early & successful physics CP violation program • Built on considerable experience in tracking software for PIs and direct participation in DCH project • core software contributions & calibration efforts for DCH • Collaboration management • Near-term operations and long-term planning and development • CP violation and B physics program !

9. The UCSD Team on BABAR Past Postdocs • Gerhard Raven (May 1998-May 2002) • Led DCH effort on calibration infrastructure, t-to-d extraction, tracking software & core offline software tools • Tracking Coordinator for BABAR offline reconstruction (May 1999-May 2000) • Co-convener of hadronic mixing AWG (Sep 2000-Jun 2003) • Now at NIKHEF • Riccardo Faccini (Apr 1998-Mar 2002) • Worked on DCH calibration algorithms & DCH data analysis • Leading contributor to vertex and composition tools design & implementation, micro-DST databases structure • Convener for Charmonium AWG (Fall 1999-present) and Coordinator for sin2b analysis effort (Apr 2000-2002) • Now Assist. Professor at Rome, current BaBar Analysis coordinator

10. The UCSD Team on BABAR • Sören Prell (Oct 1999-Aug 2002) • Developed & maintained main fitting tools of sin2b and B0 mixing measurements, including all related studies of reliability and sensitivity to systematic error sources • Leading effort on DCH t-to-d calibration studies and improvements, including resolution (Aug 2000-present); DCH Operations Manager (Jul-Dec 2001) • Now Assist. Professor at Iowa State • Shahram Rahatlou (Oct 2002-Jan 2005) • Reconstruction Manager for BaBar offline software • Software czar for Breco analysis working group common software • Measurement of BD(*)0 K(*)0modes sensitive to sin2b+g • Now Assist. Professor at Univ. of Rome • Daniele del Re (Jan 2003-present) • Leader/liaison for software migration of Breco AWG to the CM2 (2003-04) • Co-convener Breco AWG (July 2004-Present), Recoil side Physics WG Coord. • Leading role in Vub measurements with Breco sample and CM2 implementation • Transitioning to CMS to fulfill urgent UCSD need • Search in progress for Rahatlou replacement; identified strong candidate Present Postdoc

11. The UCSD Team on BABAR Graduate Students • Shahram Rahatlou (Sep 1998-Oct 2002) • Worked on micro-DST database, composition tools, Monte Carlo support for analysis, and first B meson reconstruction • Wrote, supported and documented BRecoUser analysis package, including production of skimmed ntuples, main support role for sin2b and mixing, essential for determinations of mistag rates • Online DAQ operations manager from Aug 2000-Feb 2001 • Main Ph.D. student on sin2b measurement • Haleh Hadavand (Sep 1999-present) • 5th-year Ph.D. student, full-time research at SLAC • Involved in DCH calibration work and DAQ online manager • Produced B+/B0 production ratio measurement; instrumental in refining KS efficiency understanding • Time-dependent CP violation in Penguin mode • expect to finish by end 2005

12. The UCSD Team on BABAR • Edward Hill (Sep 1999-present) • 5th-year Ph.D. student, full-time research at SLAC • Involved in DCH calibration work and DAQ online manager • Thesis on precise measurements of Vubusing fully reconstructed Breco Sample ; expect finish in next six months • David MacFarlane: DCH System Manager (1995-2000); Publications Board Chair (Nov 1999-Nov 2001); Executive Board member (Jun 2001-Oct 2003); Chair, Long-Term Upgrade Task Force (Feb 2002-Jan 2003); Spokesperson (Sep 2004-present). Plans to move on to SLAC • Vivek Sharma: SVT liaison for ComDet, Speakers Bureau Chair (Jun 2000-Jun 2001); Founder & Co-convener of Breco AWG (Sep 1999-Sep 2004), Publications Board (Oct 2002-Sep 2005) Other Major Roles

13. Recent BaBar Results where UCSD Physicists Have Played Important Roles Focus on measurements defining Or Testing The Unitarity Triangle

14. Over-Constraining The Unitarity Triangle measure UT angles by measuring CP violating asymmetry in B decay measure UT sides by measuring B semileptonic and radiative decay rates Measure both ! Angles and Sides

15. For single amplitude CP Violation in B0 System CPV through interference between mixing and decay amplitudes Directly related to CKM angles for single decay amplitude

16. Cartoon of (4S)B0B0 Evolution & Decay

17. sin2b From bccsis Now a Precision Measurement • sin2b from these final states belongs to a special class of definitive • measurements in particle physics • Theoretical uncertainties << 1%, so its interpretation is clear • data-driven measurement, statistics limited, with very little dependence on simulation or theoretical assumptions. UCSD group played leading role in defining sin2 and similar time-dependent CPV measurement in BaBar, analyses(based on our method) now gets updated routinely following each major growth in data sample

18. Prize For Best PhD Dissertation At a US University or Laboratory Citation: "For his role in the development of the tools needed for the analysis of B factory data, including the tFIT program, a unique and comprehensive fitting framework for time-dependent analyses. The tools he developed played a key role in the observation of CP violation in the B system by the BaBar collaboration. These tools will be essential to the ongoing program of work as the B factories continue to probe the origins of CP violation." PhD Thesis Advisor : Vivek Sharma 2004Mitsuyoshi Tanaka Dissertation Awardto Shahram Rahatlou University of California, San Diego

19. PRL 94, 161803 (2005), (hep-ex/0408127) sin2b = 0.722  0.040 (stat)  0.023 (sys) sin2b from B cc K0 227 M BB B(cc) KS (CP odd) modes BJ/ψKL (CP even) mode asymmetry is opposite!

20. Present CKM fit Present WA Evolution of sin2b measurements First precise test of the CKM picture, has led to a paradigm shift Look now for corrections rather than alternatives to CKM ansatz

21. Probing The CKM Angle : “Dodging Penguins” UCSD Role: VS & DBM (with Jawahery, Hocker) = Review Comm Uncommon analysis (VS) Complete immersion in analysis for over 2 years

22. CKM Angle  and Penguin “Pollution” • Original hope was to measure  from TD CPV in B0 + - Neglecting Penguin diagram T P

23. Recent Breakthrough: CKM Angle  From CPV in B0  + - BABAR

24. Constraints On a Dominated By B0  + - BABAR only Mirror solutions disfavored People can do unimaginable things with good quality data samples! RC: VS, DBM, Jawahery, Hocker

25. Probing The CKM Angle :Clean Modes Are Rare UCSD Role: B-DK- analyses developed in Breco AWG under guidance of conveners VS (2003-4) and del Re (2005) B D0K0 analysis authored by Rahatlou & VS

26. Relative strength of the two B decay amplitudes matters for interference Want rb to be large to get more interference  Large CP asymmetry 0.1-0.3 CP Asymmetry In BDK Decay   Look for B decays with 2 amplitudes with relative weak phase 

27. Schematic view of the interference 2  from B±D0 K±: D0 KS + - Dalitz Analysis

28. B-D0K- B+D0K+ BD0K ; D0KS p+p- Dalitz Plot Distributions B+D0K+ B-D0K- Differences between B+ and B- plots signify direct CP violation. Analyses STATISTICS limited

29. g: BABAR and Belle results (Dalitz method) non-K* rB value controls the CPV not well measured so far (degrees) The error on g is very sensitive to the value of rB 0.1 0.2

30. Prospects For sin(2b+g) with B0/B0 D(*)0K(*)0 • Interference between decay and mixing • Advantages: • Expected large asymmetries • Time-dependent measurement with K0  KS • Probe rB in self-tagging final state K*0K-p+ • Disadvantages: • Color suppressed decays: Smaller (x 50) branching fractions than Ks • Analysis is data starved ! Strong phase difference

31. B D(*)0K0Yields andRates D0 Sidebands N104 ± 14 D0 Sidebands N17 ± 5 BaBar * Comb./0.01 GeV Comb./0.01 GeV E(GeV) E(GeV) 205 million BB Preliminary Shahram Rahatlou Vivek Sharma Signal yields are as expected

32. Vcbtransition N=77 ± 13 Probing rB From Self-Tagging B0 D0K*0 & B0 D0K*0 Vub transition BaBar  E (GeV) E (GeV) 205 million BB Preliminary

33. Unitarity Triangle from CP Violation Measurements Alone New B Factory milestone: Comparable UT precision from CPV in B decays alone Overconstrained: subsets of measurements can be used to test for new physics

34. New Physics ? Standard Model Probing New Physics Contribution to CP Violation Via “Penguin” Loops in B Decays << Testing  Vs “” >> SM UCSD contribution: CPV in clean B0KS KS KS ; H.Hadavand Thesis

35. Compare sin2 with “sin2” from CPV in Penguin decays of B0 Both decays dominated by single weak phase Tree: Penguin: New Physics? 3 ? Must be if one amplitude dominates

36. Haleh Hadavand Thesis K0s B0 K0s K0s

37. Summary of “Penguin” Vs  : Summer 2005 Charmonium s-Penguins 2.4s between CP violation in s-penguin vs sin2b (cc) About 0.5s loss vs Winter 2005 due to shift in charmonium  average (new Belle value lower than previously)

38. Haleh’s mode very clean ! How Good is The SM prediction For Penguin Modes? 2-body: Beneke, PLB 620 (2005) 143 Calculations within framework of QCD factorization 3-body: Cheng, Chua & Soni, hep-ph/0506268 Theory suggest  > 0, opposite to exptal observation Tantalizing at present Need more data to clarify !

39. p Breco e- D* e+ n Xu l Brecoil Recoil Side Physics : A UCSD Innovation • Crucial measurements of sides of UT require digging out tiny signal from normally overwhelming background. Examples are • bu l for Vub measurement • bs and bd for |Vtd/Vts| measurement • Spinoff from sin2 project Algorithm for reconstructing massive samples ( 4000/fb-1) of fully reconstructed B mesons • Use knowledge of kinematics of fully reconstructed B to study decay of recoiling B in (4S) B B BReco Daniele del Re

40.    Measurement of |Vub| from Inclusive Semileptonic Decays BaBar data used in Aneesh’s |Vcb| analysis derived using the recoil side physics method

41. Inclusive El spectrum Rate Shape |Vxb|2 El[GeV] Inclusive Mx spectrum Shape (log-scale) bul Rate for Mx<1.55 Inclusive Semileptonic Decays: The Big Picture

42. Xu n l p D* Xu B B Y(4s) Y(4s) Breco Brecoil D* Y(4S) l p n Recoil Side Measurement of bul Kinematics Good Example of Recoil-side physics Can now “Reconstruct” Neutrino 3-vector, q2 Reco side Recoil side missing mass squared • MX reconstruction • Kinematic constraints to • improve MX resolution B Candidate Mass

43. signal region q2 (GeV2) mX (GeV) theory Isolating bu l  From Dominant (x50) bc l background bc bu bu misreco Analysis sensitivity (Stat. vs Theory error) optimized for present sample Good to reach ~ 6% theory precision with x 3-4 data samples

44. Bottomline on Vub From Inclusive Measurements The Recoil side method has the best potential for precise measurement of |Vub| with larger data samples + bs data BaBar measurements led by Daniele del Re & Ed Hill (thesis)

45. The Emerging Big Picture With improved Measurements of |Vub| Overconstrained: growing set of independent measurements are remarkably consistent with CKM picture

46. Double again from 2006 to 2008 ICHEP08 Double from 2004 to 2006 ICHEP06 BaBar Projection For Data Sample Growth Integrated Luminosity [fb-1] ICHEP04

47. Future Activities of UCSD-BaBar Group • Since BaBar’s beginning, UCSD PIs, post-docs and students have led BaBar’s productivity • MacFarlane’s stated move to SLAC in Jan 2006 diminishes UCSD’s current high profile role in BaBar management and participation in BaBar beyond 2008 • Does not significantly alter UCSD’s ability on near term (2008) physics objectives which are based on our long term investments in : • Precise measurement of Vub from fully reconstructed B sample using recoil side technique pioneered by UCSD • Search for bu amplitude in B0 D0K0 family of decays in pursuit of angle  • CPV in bs Penguin decays as clean barometer of NP • Each of these measurements have a well defined & vetted analysis procedure in place (analysis method published already) but are each currently STATISTICS limited. • In 2006, plan to shrink the UCSD-BaBar group to • 50% of VS (other 50% directed to CMS) ; • One full time post-doc concentrating on physics analyses above • retain possibility of one graduate student doing BaBar analysis and then moving to CMS DAQ in ~2008 • Yet deliver on the physics goals stated above assuming projected luminosity profile

48. Local Organizers Ben Grinstein, Aneesh Manohar, Frank Wuerthwein, VS Thank You ! DOE • Thanks for generously supporting the CKM2005 workshop at UCSD • Essentially six workshops within a workshop + satellite meetings • Meeting attracted best of the best (~ 230 in all) • Lively discussions of new Expt. and theory ideas for future precision • Important service to the global Heavy Flavor Physics community

49. Unused Slides

50. Ranking Penguin Modes by SM “pollution” Naive (dimensional) uncertainties on sin2 Decay amplitude of interest SM Pollution f f Gold SemiGold Bronze Note that within QCD Factorization these uncertainties turn out to be much smaller !