Super BABAR Plans & Status

1. Super BABAR Plans & Status David B. MacFarlane UC San Diego & SLAC 2nd Super B Workshop in Hawaii April 20, 2005

2. Latest News from PEP-II & BABAR • First collisions in PEP-II early morning April 15 • Began routine data collection with BABAR late Monday night • PEP-II delivered up to 4.8x1033 on Monday night; improving rapidly • LER and HER trickle injection operational • Very fast start once collisions achieved; much faster than previous Run 4 startup • BABAR & PEP-II are very pleased & excited to be back in the game • Installed upgrades to PEP-II should allow at least 1.3x1034 • Upcoming run will extend through to July 31, 2006, with only one month interruption in October for PPS certification Super BABAR Status & Plans

3. Outline • Summary of PEP-II/BABAR study of scenarios for Super B Factory • Try to give you a sense of the thinking behind our push to very high luminosity • Developments at DOE and SLAC concerning future of PEP-II and Super PEP-II/BABAR opportunity • Substantial change in outlook at SLAC & a potential opportunity to look at a collaborative effort on a Super B Factory Super BABAR Status & Plans

4. BABAR Roadmap Study: Jan – July 04 • Defining physics case for Super B Factory • Primarily New Physics sensitivity in CP violation & rare decays • Capability for precision SM measurements as benchmark for New Physics • Requirements of viable project plans • Factor in duration of approval and funding process • Collider options and upgrade capabilities • Detector capabilities & requirements in light of machine parameters & projected backgrounds • Integrated scenarios for collider and detector construction, with implications for time to first data & competitiveness • Projections of physics reach in light of competition & other opportunities • Projections of samples & sensitivities; analysis of physics reach Super BABAR Status & Plans

5. Physics Case for Super B Factory • Lots of work done, but everyone not convinced yet • Super B is not yet part of the US long-range planning for HEP • National Academy study could change this • Will compete with other physics opportunities in 2010-2015 • Most notably large-scale neutrino physics • Case rests primarily on ability to explore flavor physics couplings of New Physics • Complementary to hadron b experiments; perhaps natural successor • Perhaps our data is already hinting at New Physics, which will motivate further precision studies of flavor physics; perhaps LHC will see direct evidence for New Physics • Physics case may very well strengthen with time • Luminosity goals & physics timeliness a major factor as well Super BABAR Status & Plans

6. Constructing a Viable Plan • What is the timeline for approval process? • What are the machine upgrade options? • Components development and replacements required • Flexibility for further luminosity improvement • Timelines for construction and commissioning • What are the detector system requirements and options? • Limits of existing detector technologies due to backgrounds • Modifications to existing technologies or possible alternatives • Impact on physics performance • Requirements for fundamental detector R&D • Uncertainties can impact approval process • Fit together elements into a coherent set of options Super BABAR Status & Plans

7. LER vacuum +IR +HER vacuum, 952MHz rf Jul 04 Jul 07 Parameters for High-Luminosity B Factory J.Seeman Super BABAR Status & Plans

8. Recommended PEP-II upgrades schemes I II III IV Detector requirements depend on projecting backgrounds for luminosities that are >20 times larger than at present Super BABAR Status & Plans

9. Input from Detector Systems • Extrapolation of backgrounds with and without luminosity component; spatial and/or angular distributions if significant; • Performance degradation with occupancy and projected limits; likewise radiation damage and projected limits; • Any modest upgrades that will increase performance range or radiation tolerance; • Speculation about options for 5-10x1035 machines. What are limits of current technologies? Long extrapolation from current background studies, which include significant luminosity-dependent component at PEP-II Super BABAR Status & Plans

10. Luminosity Dependent Backgrounds Luminosity term depends on IR design M.Sullivan Super BABAR Status & Plans

11. SVT Backgrounds: Bottom module Assumes striplets increase granularity 4-fold B.Petersen, F.Forti Super BABAR Status & Plans

12. Monolithic Active Pixels • Option for very high luminosity is MAPS = Monolithic Active Pixels = sensor and electronics on the same substrate. • R&D on MAPS started in several places, including Pisa • Possible approaches: • Integrate electronics on the high resistivity substrate usually employed for sensors: 4 times thinner total material • Active components are not of the best quality • The fabrication process is highly non-standard with large feature size (>1-2mm) • Use the low resistivity substrate of standard CMOS process as sensor • Can use standard sub-micron process with state-of-the-art electronics Far from a proven technology: fundamental R&D required Super BABAR Status & Plans

13. DCH Occupancy Based on 2004 Studies 100% Lumi term 20% Lumi term 4 x cells 4 x cells M.Cristinziani Super BABAR Status & Plans

14. Options for Beyond 2x1035 • Basic configuration is • Leave SVT geometry unchanged; replace DCH with 4-layer silicon tracker with lampshade modules. Remove support tube • Radii of barrel part of SVT modules: 3.3, 4.0, 5.9, 12.2, 14.0 cm • Radii of barrel part of CST modules: 25,35,45,60 cm Current detector All silicon tracker 60 cm F.Forti Super BABAR Status & Plans

15. Present detector Future? Momentum Resolution F.Forti Super BABAR Status & Plans

16. Occupancy Projections 1036 7x1035 2x1035 Is this a functional EMC? Versus ~8 physicsclusters EMC Background Projections Radiation Damage Projections Degradation of light output with luminosity EMC lifetime limit: about 20 ab-1 Super BABAR Status & Plans

17. Radiation-Hard Calorimeter Options • Lutetium (+Yttrium) OxyOrthosilicate [LSO or LYSO] • Fast light output in 40ns; solves occupancy problem. • Smaller radiation length 1.15cm (CsI 1.86cm) and Moliere radius 2.3 cm (CsI 3.8cm) • Believed to be radiation hard to 100MRad! • Currently cost is ~$40/cc; pushes radius towards 700mm • Liquid Xenon • Fast light output again, within ~20ns. • Radiation length is 2.9cm: need all of radial space between 700 and 1350mm for cryostat, liquid Xenon and readout. • Moliere radius 5.7cm: long. sampling to separate overlaps. • Cost of Liquid Xenon is $2.5/cc Both Rad Hard crystal and Liquid Xenon options require EMC inner radius reduction to about 70cm: need to replace DRC bars as well Super BABAR Status & Plans

18. SVT striplets Thin pixels Wire chamber Silicon outer tracker CsI EMC Rad Hard EMC+DRC bars DRC SOB replacement Summary of Upgrade Options LER replacement + HER replacement + 952 MHz rf [No x 2 for crabbing] 1.5 2.5 5.0 7.0 x 1035 Super BABAR Status & Plans

19. Scenario 1: Detector Upgrades • Replace inner layers of present SVT with radiation hard upgrade • Replace DCH with small-cell version and faster gas • Replace DRC SOB • Replace forward EMC • Replace IFR forward endcap Super BABAR Status & Plans

20. Scenario I LER replacement Luminosity deadend SVT striplets Wire chamber CsI EMC DRC SOB replacement [No x 2 for crabbing] 1.5 x 1035 Super BABAR Status & Plans

21. Scenario 2: Detector Upgrades • Replace inner layers of present SVT with radiation hard upgrade • Not much headroom with conventional strips • Replace DCH with small-cell version and faster gas • Drift chamber may not work at this luminosity and has no headroom • More likely we would have to go to an all silicon tracker • Replace DRC SOB • Replace forward EMC • Barrel EMC has limited lifetime of a few years • Replace IFR forward endcap Super BABAR Status & Plans

22. Scenario 2: Unlikely Solution LER replacement Detector Limited SVT striplets Wire chamber CsI EMC DRC SOB replacement [No x 2 for crabbing] 2.5 x 1035 Super BABAR Status & Plans

23. Scenario 2: More Viable Solution LER replacement Collider Limited SVT striplets Silicon outer tracker Rad Hard EMC DRC replacement [No x 2 for crabbing] 2.5 x 1035 Super BABAR Status & Plans

24. Scenario 3: Detector Upgrades • Replace inner layers of present SVT with thin pixels • Replace DCH with all silicon tracker • Replace DRC SOB and bar boxes due to smaller radius for EMC • Not at all clear that DRC will work at these luminosities • Replace EMC with either radiation hard crystals or liquid xenon • Replace IFR forward endcap Fundamental R&D for thin pixels drives approval schedule and overall timeline Impossible to predict timeline for successful development Super BABAR Status & Plans

25. Scenario 3 LER replacement + HER replacement + 952 MHz rf Technology Limited Thin pixels Silicon outer tracker Rad Hard EMC DRC replacement [No x 2 for crabbing] 7.0 x 1035 Super BABAR Status & Plans

26. Scenario 4: Detector Upgrades • Replace inner layers of present SVT with segmented strips • Should be viable to about 5 x 1035 • Develop thin pixels and replace inner SVT at an appropriate time to go higher in luminosity • Replace DCH with all silicon tracker • Replace DRC SOB and bar boxes due to smaller radius for EMC • Not at all clear that DRC will work at these luminosities • Replace EMC with either radiation hard crystals or liquid xenon • Replace IFR forward endcap Super BABAR Status & Plans

27. Performance limit Upgrade Plan: Initial 5x1035 Project LER replacement + HER replacement + 952 MHz rf SVT striplets Silicon outer tracker Rad Hard EMC DRC replacement [No x 2 for crabbing] 2.5 5.0 7.0 x 1035 Super BABAR Status & Plans

28. Upgrade Plan: Ultimate Reach LER replacement + HER replacement + 952 MHz rf SVT striplets Thin pixels Silicon outer tracker Rad Hard EMC DRC replacement [No x 2 for crabbing] 2.5 5.0 7.0 x 1035 Super BABAR Status & Plans

29. Important Factors in Upgrade Direction • Project is “tunable” • Can react to physics developments • Can react to changing geopolitical situation • Size of interested community, depth of financial support • Will emerge from BABAR and Belle, but could be attractive to wider community in context of other opportunities • As we learn more about machine and detector requirements and design, can fine tune goals and plans within this framework • Project has headroom • Major upgrades to detector and machine, but none contingent upon completing fundamental R&D • Headroom for detector up to 5 x 1035; with thin pixels beyond • Headroom for machine up to 8.5 x 1035; requires additional rf, which can be staged into machine over time Super BABAR Status & Plans

30. Possible Timeline for Super B Program Construction of upgrades to L = 5-7x1035 Super B Operation Super-B Program R&D, Design, Proposals and Approvals 2001 2003 2005 2006 2008 2010 2011 2012 Construction Installation LOI CDR Commission P5 Planned PEP-II Program (June 30, 2003) (End 2006) (PEP-II ultimate) Super BABAR Status & Plans

31. Scale change! Projections for Super B Factory f0KS KSp0 jKS h’KS KKKS Luminosity expectations: Super B Factory 5-7x1035 cm-2s-1 K*g 5s discovery region if non-SM physics is effect of 0.15 2004 2012 Projections are statistical errors only; but systematic errors at few percent level Super BABAR Status & Plans

32. Comparisons: Projections for p+p- s(Spp) Lint Effective number of tagged events Error on sine amplitude PEP-II, KEKB Super B-Factory 10/2011 SuperB LHCb BTEV Super BABAR Status & Plans

33. Lint s(d) Projections for 2-Body Isospin Analysis [Estimate: Summary of a range of errors depending on BFs, asymmetries] Effective number of tagged events Error on delta [degrees] SuperB Super BABAR Status & Plans

34. Projections for K*g PEP-II, KEKB Super B-Factory 10/2011 Effective number of tagged events Error on sine amplitude SuperB Super BABAR Status & Plans

35. Developments at DOE • Budgetary backdrop in US • US domestic discretionary budget is under enormous pressure for the next few years at least: 5-year projections are for 3.7% decrease through to FY2010 in then year dollars • Priorities for US program • Highest priorities at present are full exploitation of Tevatron, PEP-II, and LHC preparations • Intention is to make room for a new suite of mid-scale experiments to be launched in 2007-2010 time frame, following ramp-down of PEP-II (2008) and Tevatron operations (2009) • Focus is on accelerator and non-accelerator based neutrino, dark matter, & dark energy experiments • Coherent plan for Fermilab as the national HEP laboratory • ILC is the long-term highest priority for future major facility, with US site the intended goal assuming international support Super BABAR Status & Plans

36. Institutional Future of SLAC • Shift in institutional funding & focus 2006-2009 • Major new $380M light source “LCLS” under construction 2005-2008: x-ray laser based on downstream 1/3rd of Linac • Additional beam lines later & use of full Linac (Stage 2) • SLAC will become dual purpose laboratory • Roughly 2/3rd light science funded by DOE/Basic Energy Sciences (BES), including entire Linac operation • Roughly 1/3rd HEP & particle-astrophysics funded by DOE/HEP • Consequences for future of PEP-II program • FY2006 budget request by DOE foresees PEP-II operation only through to end of FY2008 • When PEP-II shuts down, there will be no longer be any machine operating for HEP on the SLAC site • Major New Physics discovery might change this end date Super BABAR Status & Plans

37. SLAC Planning for HEP • Plan presented by Jonathan to National Academy Long-Range Planning Committee in January • Long-term priority is to play a leading role in the ILC, independent of site • Follows guidance from SLAC scenarios studies • Follows strengths & technical expertise of lab • Follows SLAC’s long-term history of leading the push for linear colliders, as well as priorities of the field and DOE • Full exploitation of the PEP-II B Factory program, including physics output, through next decade • Pursuit of an exciting & growing suite of possible astro-particle physics experiments • Fill in behind the ILC long-term goal with a yet-to-be-determined new accelerator-based project after PEP-II Super BABAR Status & Plans

38. Consequences for Super B Factories • Super PEP-II is not presently part of SLAC’s long-range plan • Does not fit with commitments to ILC & LCLS, or priorities from DOE in tight budget situation • Could change depending on success of turning ILC into an approved international project • Members of PEP-II & BABAR communities are starting to discuss future options • Super KEKB is a possibility for a core part of PEP-II/BABAR, depending on the strength of the physics case & competitiveness with other physics opportunities • New participants could lead to expansion of scope for the Super B project and/or a more aggressive timescale Super BABAR Status & Plans

39. Conclusion • Ideas for Super PEP-II/BABAR do not fit in SLAC plans at present • Reflects changes underway to SLAC’s scientific mission, which is broadening in a big way into light science • Core parts of PEP-II/BABAR are looking at future options outside SLAC • Early in a process of examining international accelerator-based physics opportunities in the next decade, including Super KEKB • Concerned about competitiveness & scope of Super KEKB; impact of planned peak & integrated luminosity goals on ability to convince international audience of the importance & viability of the project • See this meeting potentially as part of a process of re-examining scope, assuming we factor in the possibility for additional US and/or European contributions to the project Super BABAR Status & Plans