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BABAR Status and Future Plans

BABAR Status and Future Plans. Marcello A. Giorgi on behalf of BaBar Collaboration QCD@Work2003 Conversano (Ba)-Italy. BaBar Physics GOALS. 1)Search for CP violation in B meson decays largely predicted by the Standard Model

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BABAR Status and Future Plans

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  1. BABAR Status and Future Plans Marcello A. Giorgi on behalf of BaBar Collaboration QCD@Work2003 Conversano (Ba)-Italy Marcello A. Giorgi

  2. BaBar Physics GOALS 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 (2001) 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

  3. 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

  4. Representing unitarity relations as Unitarity Triangles The unitarity condition of CKM matrix VV+=V+V=1gives 6 relations between the matrix elements as : VudV*ub + VcdV*cb + VtdV*tb =0 (in this relation the 3 terms have the same order of magnitude ~O(l3) and it can be graphically represented in a complex plane as a triangle with sides of comparable length. Other relations have terms of different order of magnitudes. E.g.: VusV*ub + VcsV*cb + VtsV*tb =0 O(l4) O(l2) O(l2) Overconstrain a,b,g and the 4 parameters of CKM r,h, A,l Marcello A. Giorgi

  5. Decaying amplitudes in SM Penguin Tree Quarks Leading Term Secondary SampleBd Angle ccs Vcb Vcs* =Al2 VubVus*=Al4(r-ih) J/Y KsbT+P(c-t) P(u-t) sss VcbVcs*= Al2 VubVus*=Al4(r-ih) F Ks bP(c-t) P(u-t) ccd Vcb Vcd* =Al2 Vtb Vtd* =-Al3 (1-r+ih) D+D- b(LT) T+P(c-u) P(t-u) uud/ddd VubVud*=Al3(r-ih) Vtb Vtd* =-Al3 (1-r+ih) pp,rp,a1p a(LT) T+P(u-c) P(t-c) Marcello A. Giorgi

  6. 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

  7. B B production threshold PEP-II Asymmetric B-Factory 9 GeV e-on3.1 GeV e+ • (4s) boost in lab frame bg = 0.55 Marcello A. Giorgi

  8. BABAR The BABAR Collaboration 10 Countries 75 Institutions 579 Physicists IFR DIRC DCH EMC COIL SVT Marcello A. Giorgi

  9. Silicon Vertex Tracker • dE/dx measurement for PID. • Measure the track parameters just outside the beam pipe. • 5 layers of double sided silicon strips Single hit resolutions in the inner layers sd0 55 mm, sz0 65mm Soft p from the D*  D ps decays extends below pT< 150 MeV/c Marcello A. Giorgi

  10. Detector of Internally Reflected Cherenkov light K/pdiscrimination 144fused silica bars (1.7 cm thick) Cherenkov light transported by internal reflection 11000PMTs, 25-50 p.e./particle 10 mrad single photon resolution Marcello A. Giorgi

  11. ElectroMagnetic Calorimeter 6580 CsI(TI) crystals Barrel 48 rings in q, 120 crystals per ring Forward Endcap 8 rings in q, 80/100/120 crystals per ring Angular coverage: 126o in q, 360o in f. p0reconstructed from p0gg, mass width varying from 5 to 9 MeV/c2 for 0.2<Ep< 4.8 GeV Electron i.d. efficiency up to90%misidentification probability at the level of1  10-3. Marcello A. Giorgi

  12. Instrumented Flux Return Number of active elements 342 barrel RPC 432 endcap RPC 32 cylindrical inner RPC Total surface covered 2000 m2 Gas mixture Argon 60.5% Freon 35% Isobutane 4.5% Electronics 50000 channels Muon identification efficiency for tight criteria e 65% for a misidentification at the level of 2% Neutral hadrons (namely KL) are detected after their interaction with iron.Only direction is measured Marcello A. Giorgi

  13. 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

  14. Sin2b and FK decay FK FKs Marcello A. Giorgi

  15. Time dependent analysis BFK In SM SFKs=sin 2b *Assume no direct CPV * From control sample B Expect zero! Marcello A. Giorgi

  16. 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

  17. 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

  18. 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

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

  20. 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

  21. 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

  22. Not only B Physics in BABAR ! A new state at m=2317 MeV decaying into D+s(1970) and p0 has been discovered by us and recently confirmed by CLEO and BELLE ! D+s p0 D+sK+K- p+ p0 D+sK+K- p+ Marcello A. Giorgi

  23. “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

  24. An Example: D0 Mixing • y parameter from ratios of D0 K, KK,  lifetimes: Comparison with previous Measurements: Marcello A. Giorgi

  25. DCS CF Mixing … and D0 Mixing from Wrong Sign Decays • Wrong sign (WS) decays D0! K+- can occur directly DCS or through mixing followed by the right sign (RS) CF decay: • WS decays are not exponential: units of 0 Mixing DCS Interference Preliminary Marcello A. Giorgi

  26. Luminosity: Present and Future with PEPII “adiabatic scenario” So far inRun 3: On peak 30.02 fb-1 Off peak 2.57 fb-1 Present peak 6.5 10 33 L/day=370 pb-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 2006: 500 fb-1 Longer term Before end of the decade: 12 ab-1 Marcello A. Giorgi

  27. Path to higher PEP-II luminosity Luminosity4.6E331E342E344E34Units I+1800 2700 3600 4500mA I- 950 1400 1760 2000mA Beta y*11.5 9 7 4.5mm Beta x*50 50 50 50cm Bunch Length1.3 1.0 0.8 0.5cm # bunches792 1300 1500 1600 Vert. Emitt.2.5 1.4 1.1 0.7nm Horiz. Emittance40/50 30/45 32/47 40/48nm (+/-) Crossing angle0 0 0 ~+/-8mrad Tune shifts (x/y)7.5/4.5 8.0/5.7 8.2/6.0 8.4/6.3x100 Number RF stations7 10 13 15 Date hardware readyJan 02 Dec 02 Dec 04 Nov 06 Date for luminosityJun 02 July 03 Dec 05 Dec 07 (J.Seeman, BaBar Collaboration meeting, Sept.2002) Marcello A. Giorgi

  28. What about the BaBar Detector? BABAR is a VERY good detector: very difficult to improve it!! No problem expected to the performance for L up to 4 1034 cm-2 s –1 Look at the innermost and outermost systems. IFR SVT Marcello A. Giorgi

  29. SVT SVT is 98% efficient. No degradation due to irradiation has been observed 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 total has been built and are on the shelf. Instrumented Flux Return Efficiency for muon and Klong detection has decreased since the beginning in 2002 the endcap has been upgraded using new RPC and thicker 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. IFR Barrel Upgrade Many RPCs die since 1999. Fraction effectively dead is now almost 40% Muon selectors losing efficiency Decision taken to increase the thickness of the absorber and to replace the bakelite RPC with a more robust detector (Limited StreamerTube). INSTALLATION 2004 &2005 Marcello A. Giorgi

  32. 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

  33. 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

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

  35.  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

  36. 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

  37. 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

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

  39. Some comments about comparison with Hadron machine expts. Lumi(10 33) sbb(10-33) bb(107/year) sbb /sqq Bfactories 10 1.1 11 3 10-1 BTeV 0.2 100000 20000 1 10-3 LHC-B 0.15 500000 75000 5 10-3 Marcello A. Giorgi

  40. 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

  41. 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

  42. Summary Babar apparatus is generally very robust and can cope with high luminosity environment above 10 34 (2004). 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 (in a more aggressive scenario 4 10 34after 2007) 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

  43. BACKUP SLIDES Marcello A. Giorgi

  44. B0+– - B0–+ Interference Region B0+– - B000 Interference Region 3-body (+-0) Dalitz analysis for  • 11 parameters (“fundamental”): • remove overall phase & normalization: 9 parameters Suffers from mirror solutions • 10 parameters (“amplitudes”): • remove overall phase & normalization: 8 parameters • obtain fundamental parameters from subsequent fit. No mirror solutions. Does not depend on particular weak phase decomposition …work in progress Marcello A. Giorgi

  45. 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

  46. 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

  47. 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

  48. Grossman-Quinn bound: BaBar, extrapolations: vs BF(00), at fixed Luminosity Upper bounds on = 2eff-2 BaBar, present data: Small gain with lumi Most powerful at small BF Marcello A. Giorgi

  49. 2 cm radius and 1 cm radius beam pipes The 1 cm radius beam pipe intercepts about 5 kW of power from the LER and nearly the same amount from HER • Minimum amount of material in the detector beampipe • This conflicts with having enough SR shielding (usually a thin coating of Au) to keep detector occupancy at acceptable levels • Minimum radius for the beam pipe • This must be balanced with therequested thickness of the beam pipe. The smaller the beam pipe the more power it must be able to handle (kW). Marcello A. Giorgi

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