11/21/2002Marcello A. Giorgi1 THE STATUS of BABAR Marcello A. Giorgi Università di Pisa /INFN/SLAC

11/21/2002Marcello A. Giorgi2 OUTLINE Down period and detector activity Ready to startup Physics Analysis Toward future achievements

11/21/2002Marcello A. Giorgi3 Down period Activity (DETECTOR) The main and programmed activities on the BABAR Detector: –the intervention on the IFR End Cap (muon/K L detector ). –The installation of new TDC in the Dirc. –The maintainance of SVT (possible because of the extraction from BABAR of Support Tube containing SVT, beam pipe and magnetic elements of interaction region)

11/21/2002Marcello A. Giorgi4 IR2 Schematics

11/21/2002Marcello A. Giorgi5 DCH damage and repair On July 31, during removal of the support tube, a bolt head cracked the DCH Be inner cylinder.

11/21/2002Marcello A. Giorgi6 DCH Damage and Repair, Summer 2002 " Support tube hit inner cylinder " 6" x 1" crack in beryllium section " No environmental contamination " IC still about 7x structural load " Filled with epoxy " Covered with Al " Helium tight (< 50 ml/min) " Electrically grounded " 5 mm clearance to support tube " No damage to nearby wires

11/21/2002Marcello A. Giorgi7 SVT work SVT has been un-cabled,taken to the clean room, split in two halves and removed from the B1 magnets Once the SVT was exposed electrical tests and visual inspections were performed. We discovered the reason for some of the failures of the 9 non functioning readout sections,some modules fixed!

11/21/2002Marcello A. Giorgi8 Rotated Tail Fixed Sections Slipped Milpac SVT Recovered Sections

11/21/2002Marcello A. Giorgi9 SVT & Support Tube Installation

11/21/2002Marcello A. Giorgi10 DIRC shutdown main activity: TDC upgrade (I)  New TDC design to allow small dead time up to 1 MHz rates expectation: rate (kHz) ~ 530 at L= cm 2 /s high inefficiency with current design Issue: background rate versus luminosity:

11/21/2002Marcello A. Giorgi11 DIRC shutdown main activity: TDC upgrade (II) TDC chips: 12 (sectors) × 14 (Front End Boards) × 4 (chips)=672 Boards: - removed and sent to external company for chips exchange - re-coded and tested in test bench at SLAC - re-installed in detector and fully tested with calibration data: OK October 11 th 2002 TDC upgrade successful ! Sector crate Front end board

11/21/2002Marcello A. Giorgi12 Typical distribution for cosmic data Occupancy: hit frequency per phototube DIRC cosmic data Timing distribution also look very good

11/21/2002Marcello A. Giorgi13 IFR Forward Endcap The improvement in the Forward Endcap REPLACEMENT OF RPC Insertion of BRASS to increase absorber thickness ADDITIONAL LAYER 18&19 (double gap) ADDITIONAL BELT around Endcap New gas system New HV distribution

11/21/2002Marcello A. Giorgi14 Absorber Segmentation 7 layers 2 cm 1 layer 7 cm 2 layers 9 cm 2 layers 13 cm 2 layers 10cm total 85 cm New Forward EndCap project Terminology: 19 slots and 15 RPC layers RPC belt Slot18/19 5 brass layers (slot 8,10,12,14,16)

11/21/2002Marcello A. Giorgi15 GT/SLAC cosmic test Cosmic test at RPC producer General Tecnica and SLAC –QA test »Gas leakage test before and after shipping »Dark current All the RPC with maximal efficiency All the RPC with maximal efficiency 96% Radiography HV Plateau HV [V] Strip Occ.

11/21/2002Marcello A. Giorgi16 Barrel IFR Upgrade The problem: dying RPCs. Muon selectors losing efficiency impacting physics Decreasing efficiency Some RPC completely off Decreasing efficiency Some RPC completely off

11/21/2002Marcello A. Giorgi17 Barrel IFR Upgrade We are now in the middle of the process to understand the best way to fix this problem. ‘Remediation’ has not been a success. Working committee formed to recommend an upgrade technology. There are three candidates: improved RPCs with better Q/C, Limited Streamer Tubes, and Scintillator read by APDs. Decision expected by January. Access for replacement of current RPCs is mechanically complex: significant engineering needed. Expect to upgrade in 2004 and 2005 to avoid an extremely long shutdown.

11/21/2002Marcello A. Giorgi18 Trigger L1 Trigger: 4x10 33 L3 Trigger: Output 4x10 33 Software trigger executes on 47 Linux farm nodes (1.4Ghz Pentium-III dual CPU with Gbit Ethernet, recently replaced 60 Sun Ultra-5 nodes). L3 algorithms run at ~4ms/event. Trigger Strategy: Goal: Trigger on physics with high, stable and measurable efficiency. Strategy: Orthogonal tracking and calorimeter triggers with high efficiency at both L1 and L3 for most physics sources. Efficiency: Total:  BB >99%,  udsc ~97% Fiducial:  ee,  >99%,   ~92%.

11/21/2002Marcello A. Giorgi19 Level-1 Drift-Chamber Trigger Upgrade Z information needed, therefore the tracking trigger must be redesigned The upgrade task: 24 Track segment finders (TSF) 8 Z-Pt-Discriminators (ZPD) 33Interface boards of 3 types All boards in prototyping phase. Expected production in Jan/03. Commissioning starts Mar/03. (will run new system in parallel to exisitng system initially with DCH trigger fiber signal splitting). ZPD prototype (9U VME): XilinX Vertex II 3000/4000 FPGAs. 120MHz databus & internal logic. Need to contain L1 rate to <3 Khz at future high luminosity running to avoid DAQ bottleneck in DCH frontend data shipping.

11/21/2002Marcello A. Giorgi20 Oep Ntuple Objy Root HPSS Event Data Flow Analysis Skims Production SimProdPrompReco COMPUTING

11/21/2002Marcello A. Giorgi21 Computing Model Discussions Current Model defined in 2000 (April review suggested an update) BaBar has 4 Tier-A sites (France, Italy, UK, US) –New German centre (probably) next year –Looking at how to best utilise these distributed resources (BaBar GRID is one tool for this) Multiple analysis formats (now) –Objectivity, ROOT and Ntuples –Multi-step process –Problems found at any level need fixes propagated to other formats A committee is currently considering the computing model with increased luminosity within a limited resource scenario (in both people and money) Attempting to replace all three with ROOT –Ntuples will still be needed, but to a much lesser extent Report will be internally reviewed on December 6th, 7th

11/21/2002Marcello A. Giorgi22 Initial targets for PEP-II and BaBar: New environment: high luminosity asymmetric collider Search for CP violation in B mesons decays: found ! Establish methods for precision B physics, rare B decays some highlights on Run 1 + Run 2 What next? Discovery potential Probe CKM model  new physics ? Rare decays, searches (not only B)  new physics ? Along the way: constrain heavy quark models BaBar Physics Analysis 25 ICHEP’02 submissions Journal publ. in preparation Active analysis subjects (  2)

11/21/2002Marcello A. Giorgi23 CP violation: sin2   cp  sin2  =  (stat)  (syst)  cp  sin2 =  sin2 =  hep-ex/ , Submitted to PRL

11/21/2002Marcello A. Giorgi24 Osaka Rome Amsterdam CP discovery in B sector

11/21/2002Marcello A. Giorgi25 Towards sin2  eff B  →    B0   B0   

11/21/2002Marcello A. Giorgi26 Semileptonic B Decays and |V cb | Fit to sum of spectra from: B  D e, D * e, D ** e, D (*)  e BR(B  X e ) = (10.87  0.18 stat  0.30 sys )% | V cb | =  exp  theory Integration over spectrum & extrapolation to p l *=0 Relation to |V cb | by Hoang-Ligeti-Monahar

11/21/2002Marcello A. Giorgi27 Penguins and rare b decays EM 54.6 fb -1 Exclusive measurements: also interesting for |V td /V ts | 2 EW 85M BB pairs QCD B   K 0 S 51 events

11/21/2002Marcello A. Giorgi28 What next? Probe CKM in detail… sin2  uncertainty still far from systematic limit Several modes can give information on each side and angle All actively analyzed in BaBar. Key element: integrated luminosity! B  ,  B     K S B   D (*)+ D (*)- B  DK B     V td V tb * V ud V ub * V cd V cb * b  ul B  (  ) l b  cl B  (  )  B 0 Mixing

11/21/2002Marcello A. Giorgi29 …and with higher and higher luminosity: Rare B decays, for instance: Loop-mediated, FCNC: b  sl + l -, b  s, b  s  Leptonic: B  , … Unique possibility at B factories: fully reconstructed B tag  0.1% efficiency, very useful for channels with missing energy ( ) Just began to exploit this possibility Charm and Tau Physics Search for mixing and CP violation in D meson decays, … Rare  decays, including LFV

11/21/2002Marcello A. Giorgi30 BABAR back again and READY !! After the down period BABAR is ready to take data in better shape than in the last July We are ready for higher luminosity with hardware and software We have an exciting Physics Program beyond the original scientific mission We are prepared to improve our muon detection (the technology of the barrel IFR will be chosen in January 2003) We continuously monitor our computing model to improve it and to make our Physics Analysis more effective

11/21/2002Marcello A. Giorgi31 Hadronic event from OPR Nov.18,2002

11/21/2002Marcello A. Giorgi32 Preliminary from task force on Long Term Upgrades The task Force will deliver soon the written report to the collaboration Some Highlights: BABAR is a pretty good detector: very difficult to improve it!! (IFR is the only intervention needed) Only a few channels are systematically limited below 1 ab -1 ; many topics would benefit from 2-3 ab -1 or more We need to integrate higher luminosity, well beyond 0.5 ab -1, to better constrain the Unitarity triangle, to study rare decays and try to open windows on New Physics. More resources to PEPII would be beneficial for Physics

11/21/2002Marcello A. Giorgi33 The enthusiatic people of BABAR

11/21/2002Marcello A. Giorgi34 BACKUP

11/21/2002Marcello A. Giorgi35 SVT Split

11/21/2002Marcello A. Giorgi36 SVT Current Status In July 9/208 readout sections were not working. NOW: 3 of them fixed. 3 read-out sections still under investigation 3 can not be fixed: No new non functioning read-out section has been introduced. We lost redundancies on 2 modules

11/21/2002Marcello A. Giorgi37 Barrel repair Four major activities –New HV distribution Replace plastic boxes FEC fixing Major failure in Feb 2002 –Gas distribution Remote monitoring –RPC remediation Try to increase RPC eff by accumulating charge

11/21/2002Marcello A. Giorgi38 Computing Online Replaced initial Solaris farm –Installed in 98/99 50 Linux machines –Extra capacity to cope with increased luminosity –Allows better rejection of background in Level 3

11/21/2002Marcello A. Giorgi39 Preliminary report from the Task Force on “Long Term Upgrades” Roy Aleksan and David MacFarlane have reported last September 2002 at the collaboration meeting held London on the activity of the Task Force set in December The final report is expected soon. Meanwhile some important considerations can be extracted from the evaluation of the task force.

11/21/2002Marcello A. Giorgi40 From task Force PEPII&BABAR have met their CHALLENGE. So far machine and detector have operated very well, beyond what anticipated No limitation for many modes from systematic effects up to 0.5 ab-1 and for many other channels up to 2-3 ab-1, it will allow us to pursue new goals toward a comprehensive study of CP and search for new physics. But many topics as V ub,V td with ,  and  with  (  ) DK (DK  ) rare decays (penguins), non b physics will benefit (they need) from higly increased statistics.

11/21/2002Marcello A. Giorgi41 From task force BABAR is a pretty good detector and it is very difficult to improve it significantly Some gain for  (similar or better for  ),but non overwhelming in improving SVT by adding an extra layer at a smaller radius. The intervention is technically difficult and the risk in reducing beam pipe diameter to 20mm or less could imply high and unquantified operational risk. A forward veto calorimeter integrated with a modified B1 looks feasible for 2005, but we could not identify so far a significant gain for Physics.