BABAR Status and Outlook Marcello A. Giorgi on behalf of BaBar Collaboration EPAC meeting - SLAC SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 1 Canada [4/18] China [1/5] France [5/55] Germany [3/30] Italy [11/101] The Netherlands Norway [1/2] [1/3] IFR USA [38/290] United Kingdom [10/66] The BABAR Collaboration DIRC 10 Countries 75 Institutions 579 Physicists DCH EMC SVT SLAC 06/12/03 EPAC meeting Russia [1/9] BABAR COIL Marcello A. Giorgi 2 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 . SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 3 CP in Standard Model Vud V Vcd V td 1 2 1 2 Vus Vub 1 Vcs Vcb 1 2 2 Vts Vtb 3 2 A (1 i ) A CKM quark mixing matrix bul B() l CP A 3 ( i ) O ( 4 ) A 2 1 Violating phase Unitarity B0 Mixing B() bcl BD(*)l SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 4 Experimental ingredients: BaBar optimized for time dependent CP asymmetries z b(4S) = 0.55 4s e- Flavor Tagging m Btag K Tag vertex reconstruction e+ B0 m Brec B0 K Coherent BB pair Dz 1 Dt b c SLAC 06/12/03 EPAC meeting J/Y m 0 s Dz Start the Clock Marcello A. Giorgi Exclusive B Meson and Vertex Reconstruction 5 Time dependent rate,flavor mixing and CP,T,CPT CPV in Mixing -Decay CPV direct Time dependent rate: dN exp(–|Dt|/tB) ( 1 ± D (S sin(DmDt) - Ccos(DmDt)) ) R D is the mis-tag dilution R is the time resolution ___ S q A cp cp p Acp q 1 p 1 Dm i 2 D SLAC 06/12/03 EPAC meeting SM 2 1 2 B0 mixing M i 2 C 2 CP and T Violation in mixing mc2 q 1 4 2 sin b 5 10 4 p mt z2 2 Im 1 A fC P CP AfCP B0 z0 CP & CPT violation Marcello A. Giorgi f CP Dt 6 Fit without the “usual assumptions”! Fit BCP and B0flavor eigenstates (D/, q/p, z and CP left FREE) sgn(Re CP ) D q p (Re CP CP ) Re z Im z 0.008 0.037(stat.) 0.018(syst.) [0.084, 0.068] 1.029 0.013(stat.) 0.011(syst.) [1.001,1.057] 0.014 0.035(stat.) 0.034(syst.) [0.072, 0.101] 0.038 0.029(stat.) 0.025(syst.) [0.028, 0.104] Preliminary 90% C.L. Direct limit on D/ Test of CPT invariance Indirect CP in mixing The “usual assumptions” work! SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 7 LOOK for N.P. in Loops? sin(2b) = 0.741 ± 0.067stat ± 0.033syst from charmonium channels Results are so far CKM compatible but… SLAC 06/12/03 EPAC meeting Marcello A. Giorgi ? ss ss ss dd 8 f KS B0 +- sin2eff With incomplete information on Penguin contamination: • • Measure S and Cfrom both sinDmDt and cosDmDt terms . Compare with predicted S and C values for given , b, |P/T|, and . Assume for 30 instance: (97 21 ) BABAR b 26 P / T 0.28 Belle 2 2 2 From sin2eff to sin2? isospin analysis, needs B0 SLAC 06/12/03 EPAC meeting Belle 1 cf. Gronau and Rosner, Phys. Rev. D65, 093012 (2002) Marcello A. Giorgi 9 B0 K) :the CP fit • Time integrated direct CP: K ACP 0.28 0.17 0.08 Preliminary ACP 0.18 0.08 0.03 • Time dependent CP: C 0.36 0.18 0.04 S 0.19 0.24 0.03 • Asymmetry between rates: 0.18 DC 0.28-0.19 0.04 DS 0.15 0.25 0.03 First step towards in B. Full Dalitz analysis in progress. SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 10 Toward : the BD0CP K approach sin2 from the triangles (Gronau-Wyler method): 0 2 A( B DCP K) where D0CP are CP eigenstate s : 0 2 A( B DCP K) BaBar measurements: Preliminary DCP D0 D 0 2 BF ( B D 0 K ) R (8.31 0.35 0.20)% 0 BF ( B D ) RCP BF ( B D 0CP K ) BF ( B D 0CP K ) (8.8 1.6 0.5)% 0 0 BF ( B DCP ) BF ( B DCP ) ACP BF ( B D 0CP K ) BF ( B D 0CP K ) 0.06 0.17 0.06 0 0 BF ( B DCP K ) BF ( B DCP K ) SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 11 Preliminary |Vub| from fully tagged SL decays Recoil of fully reconstruted B (~4KB /fb-1) bul signal: MX (< MD) ( ~ 60-80%) S/B 1.7: good! D(*) SLAC 06/12/03 EPAC meeting Breco Xu Brecoil Y(4S) Marcello A. Giorgi l 12 Rare B decays b u : tree, CKM suppressed tree QCD penguin Possible New Physics signatures: rates and phases from virtual particles in the loops b s,d: Radiative (QCD, EM, EW) Penguins FCNC EM penguin EW penguin probes b inside B Leptonic decays: B0 l+l-, B , B l+, … SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 13 Not only B Physics in BABAR ! A new state decaying into D+s(1970) and 0 has been discovered by us and recently confirmed by CLEO! D+s 0 D+sK+K- + 0 D+sK+K- + SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 14 Charm, tau discovery potential An example: D mixing Very small in the S.M. 2 additional suppression 0.05 ms2 md2 mW2 0 Another example: lepton flavour violation S.M., extended to include mixing and mass: SU 3 limit BR(t m~ O(10 - 34) A window for new physics “short distance” x Vcd,cs W- Vud,us c D0 d,s u D0 d,s u c V* ud,us “long distance” -iy W+ V* cd,cs K-, D0 D0 K+,+ SLAC 06/12/03 EPAC meeting 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 15 Luminosity: Present and Future So far in Run 3: On peak 30.02 fb-1 Off peak 2.57 fb-1 Summer 2002 and FY2002 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 By end 2006: 500 fb-1 FY2003 Longer term By the end of the decade: 12 ab-1 SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 16 Next about sin2b • Extrapolated statistical and systematic uncertainties Param. Channel sin2b J/KS Golden D*D* J/0 f KS ’ KS Im( +) S S S Statistical uncertainty (stat)/(syst) 0.08 ab-1 0.08 / 0.03 0.07 / 0.03 0.43 / 0.13 0.49 / 0.16 0.50 / 0.09 0.34 / 0.03 1 2 L (stat)/(syst) 0.5 ab-1 0.037 / 0.018 0.031 / 0.018 0.16 / 0.07 0.20 / 0.20 / 0.14 / Golden modes (stat)/(syst) 2.0 ab-1 0.018 / 0.018 0.015 / 0.018 0.08 / 0.03 0.10 / 0.10 / 0.07 / (*) stat syst at L 2 ab1 (*) This syst error of 0.018 is dominated by DCS decays of charm in K tagged events. Lepton tag is not affected ! SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 17 What next for Sin 2b Pure penguin process B FKs NEW PHYSICS ? New quanta in the loop? The present value with 80 /fb is: S=sin2b=-0.19-0.50+0.52 stat.±0.09syst. With 2/ab (S) goes down to 0.1 But also B SLAC 06/12/03 EPAC meeting ’ K and B KKK Marcello A. Giorgi 18 Extapolations for sin2eff Results (0.08 ab-1) for BFactories Param. S C BaBar Belle 0.02 0.34 0.05 -1.23 0.41 (+ 0.05-0.07) -0.30 0.25 0.04 -0.77 0.27 0.08 Extrapolated errors (BaBar) Param. Channel S C +- SLAC 06/12/03 EPAC meeting (stat)/(syst) 0.08 ab-1 0.34 / 0.05 0.25 / 0.04 (stat)/(syst) 0.5 ab-1 0.12 / 0.03 0.10 / 0.03 Marcello A. Giorgi (stat)/(syst) 2.0 ab-1 0.06 / 0.05 / 19 from B-gD0(CP)K-: projections Recent experimental results (BaBar) ( B D1 K ) n1 1.02 0.29 0.02 ( B D0 K ) 500 D0 K K ( B D1 K ) p1 (0.72 0.26 0.02) ( B D0 K ) ACP 0.17 0.23 0.08 A( B D0 K ) r A( B D0 K ) O (0.1) Toy MC projections: (Fit unreliable for r = 0.1) r=0.3 (0.5 ab-1), sin2.75 fit:sin2.72.2359.91.2o r=0.2 (2ab-1), sin2.75 fit: sin2.71.1458.57.4o r=0.2 =60o D=30o SLAC 06/12/03 EPAC meeting (2ab-1) ACP=0.174 0.031 Marcello A. Giorgi 20 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: bul, bcl, background Errors: Statistical L(ab-1) = 0.08 0.5 2.0 stat(%) = 7.0 2.8 1.4 10 0.6 Mx (GeV) Experim. Systematic ~5% (now) 2.5% (bcl bkgd) Theoretical ~ 9% (b ulabove cut) SLAC 06/12/03 EPAC meeting ((mb)=90MeV) 5% Marcello A. Giorgi 21 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 D(*) SLAC 06/12/03 EPAC meeting “B – beam” Breco Y(4S) Marcello A. Giorgi l 22 Integrated luminosity vs physics 2002 2006 BaBar 2009 ? t m 0.1 Continuous improvement SLAC 06/12/03 EPAC meeting 0.5 1.0 2.0 10. Ldt ab 1 Vub Vcb sin 2 b sin 2 X s l l , K *l l X s , K * t , m sin 2b Marcello A. Giorgi 23 Some comments about comparison with Hadron machine expts. CKM parameters BABAR/Belle 2 ab-1 Sin2b(charmonium) 0.015stat/0.018syst Sin2b (penguins bsss) 0.10 stat in 2S eff(B0 0.06 stat eff – ( B0 ) <10° Sin(2b) (B0 D* ) 0.15 (B DK) 7° |Vub| 1.4%+ Th. Unc.(now better 10%) BTeV/LHC-B 107 s 0.025/0.014 ---0.024/0.056 ------<10°/<19° ---- Of course Bs mixing and decay can be studied well at hadron machines ( and a lot of good physics from Bs) SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 24 Rare decays - Summary Channel BF bs 3.3±0.3 10-4 BK* B () 510-5 210-6 25K ---- bsmm bse+eBK*mm BK*e+e- 6.±1.5 10-6 3.6K bs BK* 4.1±0.9 10-5 5.10-6 Bt Bm 510-5 510-7 2.±1 10-6 BTeV/LHC-B (107 s) ---- 2.2K/4.5K ---------- BABAR/BELLE (2 ab-1) 44.0K 6.8K(Btagged) 24.0K 1.2K 1.2K 1.4K 0.5K 0.6K Asymmetries! 30 6 70 35 Limit< 10-8 tm Rates… Fully reconstructed B on the other side are used The so called B beam option Bfactory and hadron machine measurements are complementary ! SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 25 What about Detector? SVT! 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 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. SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 26 Instrumented Flux Return • 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 SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 27 • • • • • BABAR RPC 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 isobutane %, CBrF3 replaced by Freon 134a C2H2F4 SLAC 06/12/03 EPAC meeting Efficiency of barrel RPCs after production ~97% Marcello A. Giorgi 28 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% • • • SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 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. 29 New Forward EndCap from nov 2002 RPC belt Terminology: 19 slots and 15 RPC layers 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 SLAC 06/12/03 EPAC meeting Marcello A. Giorgi total 85 cm 30 RPC problems (post mortem photo) Linseed oil – uncured oils move under HV and warm temperatures Excess oil Graphite layer develops high resistance Gas inlet Debris Internal debris and whiskers 5% of barrel has HV problems before New HV distribution Whiskers SLAC 06/12/03 EPAC meeting ~50% of the barrel modules leak (many have normal efficiency) Front End electronics problems Marcello A. Giorgi Opposite side 31 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. SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 32 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 . SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 33 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->including Dalitz plot analysis. FUTURE – In 2005 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 : SLAC 06/12/03 EPAC meeting “ Pseudo B beam” Marcello A. Giorgi 34 BACKUP SLIDES SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 35 Flavour mixing and CP,T,CPT Dm=mH-m L 2|M12| 0.5ps-1 D=H-L |M12|Re (12/M12) 1/ 1.6 ps D SM q 1 p CP and T Violation in mixing As in K sector where k=(p-q)/(p+q) mc2 q 1 4 2 sin b 5 10 4 p mt SLAC 06/12/03 EPAC meeting ~O(10-3) SM Marcello A. Giorgi 36 Flavour mixing and CP,T,CPT CP an CPT conservation if H11=H22 z2 M i 2 Dm i 2 D z0 11 22 2 M M 22 M 11 _ _ Prob (( B B ),t) Prob (( B B0 ),t) 0 0 0 2 CP and CPT VIOLATION Assumptions made in the usual sin2b analysis: D H L 0 i M 12 2i 12 q M M (11 22 ) 11 22 2 1 z 0 i i p M 12 2 12 Dm 2 D SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 37 Time Dependent CP asymmetries CPV in mixing-decay interference direct CPV dN exp(–|Dt|/tB) ( 1 ± D (S sin(DmDt) - C cos(DmDt)) ) R S 2 1 2 C 1 2 1 2 Flavour tag Amplitude ratio B0fcp/B0fcp CP eigenvalue B mixing D mis-tag dilution R time resolution q Vtb*Vtd 2 if M e p VtbVtd* Measured from data (Flavour sample)! SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 38 Search for B+ t+ Preliminary Semileptonic tags: BF(B+ t+) < 4.910-4 (90% CL) Fully reco tags: BF(B+ t+ ) < 7.710-4 (90% CL) cosqB,Dl for B D0X tags combined: < 4.1 10-4 Total signal-side neutral energy D0 t Y(4S) B t candidate Semileptonic tag SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 39 RPC efficiency 00 Gas change -1.4% /month -0.56%/month -1.4% /month SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 40 • Detector studies Realization that the RPC efficiencies did not recover after cooling spurred detector studies A wide spread of plateau curves were measured. – 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 SLAC 06/12/03 Marcello A. Giorgi – Put weights over inefficient EPAC meeting regions 41 D. Piccolo RPC radiography The RPC efficiency was mapped in 2D showing irregular regions of reduced efficiency. SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 42 Occupancy plots for run 38637 Brick shields ~.8 m from L 16 SLAC 06/12/03 EPAC meeting Marcello A. Giorgi 43