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BABAR Status and Outlook

BABAR Status and Outlook. Marcello A. Giorgi on behalf of BaBar Collaboration EPAC meeting - SLAC. BABAR. Canada China France Germany Italy The Netherlands Norway Russia United Kingdom USA

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BABAR Status and Outlook

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  1. BABAR Status and Outlook Marcello A. Giorgi on behalf of BaBar Collaboration EPAC meeting - SLAC Marcello A. Giorgi

  2. BABAR Canada China France Germany Italy The Netherlands Norway Russia United Kingdom USA [4/18] [1/5] [5/55] [3/30] [11/101] [1/2] [1/3] [1/9] [10/66] [38/290] The BABAR Collaboration 10 Countries 75 Institutions 579 Physicists IFR DIRC DCH EMC COIL SVT Marcello A. Giorgi

  3. BaBar Physics GOALS New environment: high luminosity asymmetric collider 1)Search for CP violation in B meson decays largely predicted by the Standard Model 2)Test extensively at this low energy scale the Standard Model by measuring precisely enough quantities to impose constraints on the Standard Model parameters CP in b sector has been established by BaBar and Belle TRY to open windows on new Physics beyond Standard Model More precise CKM measurements, Rare B decays, Charm study, Tau rare decays . Marcello A. Giorgi

  4. B0 Mixing bul B()  B() l bcl BD(*)l CP in Standard Model CP Violating phase CKM quark mixing matrix Unitarity Marcello A. Giorgi

  5. z FlavorTagging m- bg(4S) = 0.55 K- Tag vertex reconstruction m- m+ B0 B0 p+ Coherent BB pair p- Dz Exclusive B Meson and Vertex Reconstruction Start the Clock Experimental ingredients: BaBar optimized for time dependent CP asymmetries J/Y Marcello A. Giorgi

  6. mixing decay CP Time dependent rate,flavor mixing and CP,T,CPT CPV in Mixing -Decay CPV direct Time dependent rate: dN exp(–|Dt|/tB) ( 1 ± D (Ssin(DmDt)-Ccos(DmDt)) )  R D is the mis-tag dilution R is the time resolution CP and T Violation in mixing SM z0 CP & CPT violation Marcello A. Giorgi

  7. The “usual assumptions” work! Fit without the “usual assumptions”! Fit BCP and B0flavor eigenstates (DG/G, q/p, z and lCP left FREE) Preliminary 90% C.L.  Direct limit on DG/G  Test of CPT invariance  Indirect CP in mixing Marcello A. Giorgi

  8. s s s d s s s d f KS LOOK for N.P. in Loops? ? sin(2b) = 0.741 ± 0.067stat± 0.033syst from charmonium channels Results are so far CKM compatible but… Marcello A. Giorgi

  9. BABAR Belle 2 Belle 1 B0 +-sin2eff With incomplete information on Penguin contamination: • Measure Spp and Cpp from both sinDmDt and cosDmDt terms . • Compare with predicted Spp and Cpp values for given a, b, |P/T|, and d. Assume for instance: From sin2efftosin2? isospin analysis, needs B0 cf. Gronau and Rosner, Phys. Rev. D65, 093012 (2002) Marcello A. Giorgi

  10. B0rp (K): the CP fit Preliminary • Time integrated direct CP: • Time dependent CP: • Asymmetry between rates: First step towards a in Brp. Full Dalitz analysis in progress. Marcello A. Giorgi

  11. Toward : the BD0CP K approach sin2 from the triangles (Gronau-Wyler method): BaBar measurements: Preliminary Marcello A. Giorgi

  12. Breco Brecoil D(*) Y(4S) l p n Preliminary |Vub| from fully tagged SL decays Recoil of fully reconstruted B (~4KB /fb-1) bul signal: MX(< MD) ( ~ 60-80%) S/B  1.7: good! Xu Marcello A. Giorgi

  13. Rare B decays Possible New Physics signatures: rates and phases from virtual particles in the loops tree b  u : tree, CKM suppressed b  s,d: Radiative (QCD, EM, EW) Penguins FCNC Leptonic decays: B0 l+l-, B  , B l+, … QCD penguin EM penguin EW penguin  probes b inside B Marcello A. Giorgi

  14. Not only B Physics in BABAR ! A new state decaying into D+s(1970) and p0 has been discovered by us and recently confirmed by CLEO! D+s p0 D+sK+K- p+ p0 D+sK+K- p+ Marcello A. Giorgi

  15. “short distance”  x Vcd,cs W- Vud,us c u d,s d,s D0 D0 u c V*ud,us W+ V*cd,cs “long distance”  -iy K-, D0 D0 K+,+ Charm, tau discovery potential • Another example: lepton flavour violation S.M., extended to include n mixing and mass: BR(t) ~O(10 - 34) An example: D mixing Very small in the S.M. • 2  additional suppression  A window for new physics lepton number is violated in many extensions of the S.M. (present limits, O(10-6) are not far from some model predictions) Marcello A. Giorgi

  16. Luminosity: Present and Future So far inRun 3: On peak 30.02 fb-1 Off peak 2.57 fb-1 FY2002 Summer 2002 and Winter 2003: Run 1 + Run 2 On peak 83.9 fb-1 Off peak 9.6 fb-1 92 M BB pairs Summer 2003: Run 3 add 40 fb-1 FY2003 By end 2006: 500 fb-1 Longer term By the end of the decade: 12 ab-1 Marcello A. Giorgi

  17. Next about sin2b • Extrapolated statistical and systematic uncertainties Statistical uncertainty Golden modes (*) (*) This syst error of 0.018 is dominated by DCS decays of charm in K tagged events. Lepton tag is not affected ! Marcello A. Giorgi

  18. What next for Sin 2b NEW PHYSICS ? New quanta in the loop? Pure penguin process B FKs The present value with 80 /fb is: S=sin2b=-0.19-0.50+0.52stat.±0.09syst. With2/ab s(S) goes down to 0.1 But also B h’ K and B K K K Marcello A. Giorgi

  19. Extapolations for sin2eff Results (0.08 ab-1) for BFactories Extrapolated errors (BaBar) Marcello A. Giorgi

  20.  from B-gD0(CP)K-: projections Recent experimental results (BaBar) Toy MC projections: (Fit unreliable for r = 0.1) r=0.3 (0.5 ab-1), sin2g = 0.75  fit: sin2g = 0.720.23, g = (59.910.2)o r=0.2 (2ab-1), sin2g = 0.75  fit: sin2g = 0.710.14, g = (58.57.4)o r=0.2 g=60o Dd=30o (2ab-1) ACP=0.174 0.031 Marcello A. Giorgi

  21. projected errors for |Vub| Selection: One B reconstructed in D(*)X Lepton momentum and neutrino mass Kaon veto, charge balance Fit Mx with constraints MX distribution fit: buln, bcln, background Errors: Statistical L(ab-1) = 0.08 0.5 2.0 10 sstat(%) = 7.0 2.8 1.4 0.6 Experim. Systematic ~5% (now)  2.5% (bcln bkgd) Theoretical ~ 9% (s(mb)=90MeV)  5% (b uln above cut) Mx (GeV) Marcello A. Giorgi

  22. Breco “B – beam” D(*) Y(4S) l p n B beam method B factories present an unique peculiarity. Events are pure B B and a full reconstruction of one side allow to treat the other as a pseudo B-beam. The study of rare decays with neutrinos are becoming possible with very high integrated luminosity. h Marcello A. Giorgi

  23. Integrated luminosity vs physics 2002 2006 BaBar  2009 ? Continuous improvement Marcello A. Giorgi

  24. Some comments about comparison with Hadron machine expts. CKM parameters BABAR/Belle BTeV/LHC-B 2 ab-1 107 s Sin2b(charmonium) 0.015stat/0.018syst 0.025/0.014 Sin2b (penguins bsss) 0.10 stat ---- in 2Saeff(B0 p+ p-) 0.06 stat 0.024/0.056 aeff – a ( B0 p0 p0 ) <10° ---- Sin(2b-g) (B0 D*p0 p0 ) 0.15 ---- g (B DK) 7° <10°/<19° |Vub| 1.4%+ Th. Unc.(now better 10%) ---- Of course Bs mixing and decay can be studied well at hadron machines ( g and a lot of good physics from Bs) Marcello A. Giorgi

  25. Rare decays - Summary Channel BF BTeV/LHC-B (107 s) BABAR/BELLE (2 ab-1) bsg 3.3±0.3 10-4 ---- 44.0K 6.8K(Btagged) BK*g 5 10-5 25K 24.0K B r (w)g 2 10-6 ---- 1.2K bsm+m- 6.0 ±1.5 10-6 3.6K 1.2K bse+e- 1.4K BK*m+m- 2.0 ±1 10-6 2.2K/4.5K 0.5K BK*e+e- 0.6K bsnn 4.1 ±0.9 10-5 ---- 30 BK*nn 5.0 10-6 ---- 6 Btn 5 10-5 ---- 70 Bmn 5 10-735 t mg Limit< 10-8 Bfactory and hadron machine measurements are complementary ! Asymmetries! Rates… Fully reconstructed B on the other side are used The so called B beam option Marcello A. Giorgi

  26. BABAR is a VERY good detector: very difficult to improve it!! (On IFR barrel is the only major intervention needed) SVT is 98% efficient. No degradation due to irradiation has been observed so far What about Detector? SVT! SVT so far tested for rad hardness up to 4 Mrad (OK!) rad tests are going on. Partial SVT replacement is considered by 2005. Almost 50% of modules built as spare. Marcello A. Giorgi

  27. Instrumented Flux Return 2000 m2 342 barrel RPCs 432 endcap RPCs 32 cylindrical RPCs Electronics 3300 Front end cards ~ 40 mV threshold 16 channels connected to alternate strips Gas 35% Freon 134a, 4.5% iso-butane, 60.5% Argon 1-3 volume changes/day High Voltage > 50 10 kV HV pods Instrumented Flux Return Marcello A. Giorgi

  28. Operates in limited streamer mode Parallel high resistivity plates (Bakelite  1011 -1012  cm ) Graphite ~100 k/ RPCs were filled 3 times with a mixture of 70% linseed oil and 30% n-pentane and dried by air for several days. Changes from L3 RPCs Polycarbonate buttons with lip replaced G10 cylindrical button Thicker oil layer Single layer with strips on both sides No mechanical envelope Nonflammable gas - low iso-butane %, CBrF3 replaced by Freon 134a C2H2F4 BABAR RPC Efficiency of barrel RPCs after production ~97% Marcello A. Giorgi

  29. 1999 • IFR complete May 99 • RPC efficiencies good • Warning signs • Some RPCs with > 100 mA were disconnected • With collision data • HV current limitations force reduction in # of RPCs • Average Efficiency low ~85% • Barrel is about 50% of total IFR coverage • Forward Endcap about 40% • Decision was taken in 2000 to upgrade the Forward Endcap with new RPC (higher QA/QC level) and with more absorber. Marcello A. Giorgi

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

  31. RPC problems (post mortem photo) Linseed oil – uncured oils move under HV and warm temperatures Graphite layer develops high resistance Internal debris and whiskers 5% of barrel has HV problems before New HV distribution ~50% of the barrel modules leak (many have normal efficiency) Front End electronics problems Excess oil Gas inlet Debris Opposite side Whiskers Marcello A. Giorgi

  32. IFR Barrel Upgrade Many RPCs die since 1999. Fraction effectively dead is now almost 40% Muon selectors losing efficiency A committee was setup in september 2002 to evaluate physics motivation for a IFR upgrade and technology. B.Ratcliff and C.Hearty were chairing the committee. After 3 months the committee Presented its recommendations to BaBar. Marcello A. Giorgi

  33. FINAL DOCUMENT May22,2003 Committee proposes to increase the thickness of the absorber and to replace the bakelite RPC with a more robust detector (Limited StreamerTube). INSTALLATION in 2004 & 2005 We have submitted a proposal and ask for your approval . Marcello A. Giorgi

  34. Summary Babar apparatus is generally very robust and can cope with high luminosity environment above 10 34 . Decision has been taken to upgrade the IFR Barrel with a different technology well established and robust (LST). Preliminary measurements of pure penguin processes for sin2b, measurements of Vub, B->DK, B->rp includingDalitz plot analysis. FUTURE – In2005 complete the installation of the IFR Barrel. Install the Spare modules of SVT, to replace the heavily irradiated modules on horizontal plane. Approach the precision measurement with 0.5/ab of integrated luminosity . Towards more than 1.0/ab explore possible openings for new physics. Study of CP asymmetries but also rare decays in b, c and tau sectors. Profit from full reconstruction of one B : “ Pseudo B beam” Marcello A. Giorgi

  35. BACKUP SLIDES Marcello A. Giorgi

  36. Flavour mixing and CP,T,CPT Dm=mH-m L 2|M12|  0.5ps-1 1/G  1.6 ps DG=GH-GL  |M12|Re (G12/M12) DG<<G SM CP and T Violation in mixing As in K sector where ek=(p-q)/(p+q) e~O(10-3) SM Marcello A. Giorgi

  37. Flavour mixing and CP,T,CPT CP an CPT conservation if H11=H22 CP and CPT VIOLATION Assumptions made in the usual sin2b analysis: Marcello A. Giorgi

  38. Amplitude ratio B0fcp/B0fcp Time Dependent CP asymmetries CPV in mixing-decay interference direct CPV dN exp(–|Dt|/tB) ( 1 ± D (Ssin(DmDt)-Ccos(DmDt)) )  R Flavour tag CP eigenvalue B mixing D mis-tag dilution R time resolution Measured from data (Flavour sample)! Marcello A. Giorgi

  39. Preliminary Search for B++ combined: < 4.1  10-4 Semileptonic tags: BF(B++) < 4.910-4 (90% CL) Fully reco tags: BF(B++ ) < 7.710-4 (90% CL) cosqB,Dlfor B  D0nX tags Total signal-side neutral energy n t p Y(4S) Semileptonic tag B candidate n D0 Marcello A. Giorgi

  40. RPC efficiency 00 Gas change -1.4% /month -0.56%/month -1.4% /month Marcello A. Giorgi

  41. Realization that the RPC efficiencies did not recover after cooling spurred detector studies Efficiency was computed as a function of position Limited tests were carried out during accesses or on a few chambers Lowered barrel temp. to 17 C. Reversed HV Increased gas flow Lowered discriminator threshold Put weights over inefficient regions No effect Gas composition was regularly tested No evidence of water vapor Detector studies A wide spread of plateau curves were measured. Marcello A. Giorgi

  42. RPC radiography D. Piccolo The RPC efficiency was mapped in 2D showing irregular regions of reduced efficiency. Marcello A. Giorgi

  43. Occupancy plots for run 38637 Brick shields ~.8 m from L 16 Marcello A. Giorgi

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