3/20/03 SLAC- B DayMarcello A. Giorgi1 BABAR Future Marcello A. Giorgi at SLAC B DAY

3/20/03 SLAC- B DayMarcello A. Giorgi2 Outline BaBar Collaboration BaBar Mission Present Achievements What Next

3/20/03 SLAC- B DayMarcello A. Giorgi3 USA[38/285] California Institute of Technology UC, Irvine UC, Los Angeles UC, Riverside UC, San Diego UC, Santa Barbara UC, Santa Cruz U of Cincinnati U of Colorado Colorado State Florida A&M Harvard U of Iowa Iowa State U LBNL LLNL U of Louisville U of Maryland U of Massachusetts, Amherst MIT U of Mississippi Mount Holyoke College SUNY, Albany U of Notre Dame Ohio State U U of Oregon U of Pennsylvania Prairie View A&M U Princeton U SLAC U of South Carolina Stanford U U of Tennessee U of Texas at Albany U of Texas at Dallas Vanderbilt U of Wisconsin Yale Canada[4/18] U of British Columbia McGill U U de Montréal U of Victoria China[1/5] Inst. of High Energy Physics, Beijing France[5/52] LAPP, Annecy LAL Orsay LPNHE des Universités Paris VI et VII Ecole Polytechnique, Laboratoire Leprince-Ringuet CEA, DAPNIA, CE-Saclay Germany[3/28] Ruhr U Bochum Technische U Dresden U Rostock January 14, 2003 Italy[11/101] INFN, Bari&U INFN, Ferrara&U Lab. Nazionali di Frascati dell' INFN INFN, Genova&U INFN, Milano&U INFN, Napoli&U INFN, Padova&U INFN, Pisa&U&ScuolaNormaleSuperiore INFN, Roma &U "La Sapienza" INFN, Torino&U INFN, Trieste&U The Netherlands [1/2] NIKHEF, Amsterdam Norway[1/3] U of Bergen Russia[1/9] Budker Institute, Novosibirsk United Kingdom [10/66] U of Birmingham U of Bristol Brunel U U of Edinburgh U of Liverpool Imperial College Queen Mary, U of London U of London, Royal Holloway U of Manchester Rutherford Appleton Laboratory The B A B AR Collaboration 10 Countries 75 Institutions 569 Physicists

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3/20/03 SLAC- B DayMarcello A. Giorgi5 LUMINOSITY After a long run period July 1,2002 Babar & PEPII RUN 2 stopped. RUN 3 has started Nov.18,2002 and after the short winter shutdow (dec 23-jan 2) operation is continuing in 2003 RUN 1 & RUN 2 PEP has delivered 98.5 fb-1 BABAR recorded 83.9 fb-1 (on peak) 9.9 fb-1 (off peak) RUN 3 PEP has delivered fb-1 BABAR recorded fb-1 (on peak) 1.16 fb-1 (off peak) B pair collected (Runs 1+2+3)  112 Million

3/20/03 SLAC- B DayMarcello A. Giorgi6 Jun 29 At the end of the present Run 3 (June 29) we expect more than 40 fb -1

3/20/03 SLAC- B DayMarcello A. Giorgi7 BaBar Physics Mission New environment: high luminosity asymmetric collider 1)Search for CP violation in B mesons 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 is FOUND ! We move now toward the second part of our mission Precision measuremets B physics, rare B decays TRY to open windows on new Physics beyond Standard Model

3/20/03 SLAC- B DayMarcello A. Giorgi8 Flavour mixing and CP,T,CPT Let us remind the Effective Hamiltonian to describe system, where the mass eigenstates B H and B L are: and =

3/20/03 SLAC- B DayMarcello A. Giorgi9 Flavour mixing and CP,T,CPT  m=m H -m L  2|M 12 |  0.5ps -1 1/  1.6 ps  =  H -  L  |M 12 |Re (  12 /M 12 )  SM CP and T Violation in mixing As in K sector where  k =(p-q)/(p+q)  ~O(10 -3 ) SM

3/20/03 SLAC- B DayMarcello A. Giorgi10 Flavour mixing and CP,T,CPT CP an CPT conservation if H 11 =H 22 CP and CPT VIOLATION

3/20/03 SLAC- B DayMarcello A. Giorgi11 Flavour mixing and CP,T,CPT Time dependence: dN  exp(–|  t|/  B ) ( 1 ± D (S sin(  m  t) - Ccos(  m  t)) )  R CPV in Mixing Decay CPV direct D is the mis-tag dilution R is the time resolution CP mixing decay

3/20/03 SLAC- B DayMarcello A. Giorgi12 CP in the Standard Model CP is explained in S.M. by the presence of a phase among the 4 parameters of the flavour mixing matrix CKM In the above parametrization,where is sin  c,  is the parameter contributing to CP

3/20/03 SLAC- B DayMarcello A. Giorgi13 O( 2 ) Representing unitarity relations as Unitarity Triangles The unitarity condition of CKM matrix V V + =V + V=1 gives several relations between the matrix elements as V ud V* ub + V cd V* cb + V td V* tb =0 (in this relation the 3 terms have the same order of magnitude ~ O( 3 ) and it can be graphically represented as a triangle in a complex plane with sides of comparable length. Other relations have terms of different order of magnitudes.Ex: V us V* ub + V cs V* cb + V ts V* tb =0 O( 4 ) O( 2 ) Overconstrain  and the 4 parameters of CKM , A 

3/20/03 SLAC- B DayMarcello A. Giorgi14  cp  cp  sin2 =  0.074sin2 =  PRL 89 (2002) Measurement of sin2  =0.741   0.034

3/20/03 SLAC- B DayMarcello A. Giorgi15 Osaka Rome Amsterdam CP discovery in B sector

3/20/03 SLAC- B DayMarcello A. Giorgi16 CP,T,CPT A simultaneous fit to tagged and untagged data gives :  m,sin2  (consistent with previous analysis) |A cp / A cp | (consistent with no direct CP violation (4.5%) 90% CL

3/20/03 SLAC- B DayMarcello A. Giorgi17 CP,T,CPT From dileptons

3/20/03 SLAC- B DayMarcello A. Giorgi18 What next for Sin 2  We can improve the expt. error on sin2  with luminosity in time dependent asimmetry for channels as: b  ccs O( 2 ) (golden as J/  Ks) or b  ccd O( 3 ) (as D (*)+ D (*)- ), where the leading term gives sin2  0.5 ab -1

3/20/03 SLAC- B DayMarcello A. Giorgi19 What next on sin2  Measure sin2  also in  K (b  sss pure penguin) B  K (*) K±K± KsKs 80 Million B pairs

3/20/03 SLAC- B DayMarcello A. Giorgi20 Time dependent analysis Results: Assuming C=0 (no direct CPV) S=sin2  =-0.26±0.51 stat. On control sample Charged K expected S=0 Found S=0.26 ±0.27 stat.

3/20/03 SLAC- B DayMarcello A. Giorgi21 BaBar (Br/10 -6 ): B0      4.7±0.6 ± 0.2 B       5.5 ± 1.0 ± 0.6 B       <3.6 Towards sin2  eff : S  and C  B  →    

3/20/03 SLAC- B DayMarcello A. Giorgi22  from  22 ’’’’  In a full isospin analysis one can measure  and  ’ from B and B decays with a 4-fold ambiguity Fix :BR(     ) = 4.7x10 -6, BR(     ) = 4.1x10 -6 and assuming BR (      x10 -6 L = 0.5 ab -1 L = 2.0 ab -1 fb -1

3/20/03 SLAC- B DayMarcello A. Giorgi23 signal BR = 0.5e-6 best case: |  eff –  | < 19 0 with 10 fb -1 At present BR(B 0 →  0  0 ) < 3.6  (81 /fb)   |  eff -  | < 51 o Grossman-Quinn bound: 22 No significant gain with luminosity Best case with this method  ’’’’ sin2  eff =  0.02 ` 0.34 ` 0.05 with 2  eff = 2  Bound on 

3/20/03 SLAC- B DayMarcello A. Giorgi24 Measuring  with B +  D 0 K Take decay B ±  D 0 1 (D 0 2 )K ± where D 0 1,2 =(D 0 ±D 0 )/  2 B+ decay amplitudes can be written as: and Gronau,London and Wyler

3/20/03 SLAC- B DayMarcello A. Giorgi25 Measuring  with B +  D 0 K + actual detector:  i =0.177 “perfect” vertex detector:  i =0.133 (no Bkg)

3/20/03 SLAC- B DayMarcello A. Giorgi26 New results with full statistics To complete the measurements odd CP eigenstates are needed as Ks  0 and Cabibbo suppressed modes

3/20/03 SLAC- B DayMarcello A. Giorgi27  from B +  D 0 K + sin 2  input value (sin 2  input value (sin 2  0.5 ab -1 Fit: sin 2    Toy MC: results for r=0.3 Fit with 2ab -1 ( perfect ): sin 2  sin 2      

3/20/03 SLAC- B DayMarcello A. Giorgi28 Measuring V ub Measure Br(b  ul ) on the recoil of fully reconstructed B. Close kinematics: P * l, Q 2 and M x available Before lepton selection: >3K events/fb -1, S/B=0.5 After lepton selection: ~500 events/fb -1, S/B=1.3 Reco side We are after the red part and one want to go as close as the D mass

3/20/03 SLAC- B DayMarcello A. Giorgi29 Current error N.B. this estimate neglects the fact that the full fledged theorethical extraction becomes feasible only with enough statistics Assuming a 5% theoretical error and a 5% experimental systematic error, here are the projections of the error as a function of the luminosity The theoretical error of 10% can be further reduced at the 5% level using all information P * l, Q 2 and M x

3/20/03 SLAC- B DayMarcello A. Giorgi30 …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

3/20/03 SLAC- B DayMarcello A. Giorgi31...more.. Charm and Tau Physics Search for mixing and CP violation in D meson decays, … Rare  decays, including LFV

3/20/03 SLAC- B DayMarcello A. Giorgi32 Integrated luminosity vs physics BaBar2006  2009 ? Physics examples: choose benchmarks 2002

3/20/03 SLAC- B DayMarcello A. Giorgi33 From task force on Long Term Upgrades Some Highlights: BABAR is a VERY 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

3/20/03 SLAC- B DayMarcello A. Giorgi34 SVT 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! Now only 4 out of 208 sections are not readable. SVT so far tested for rad hardness up to 4 Mrad (OK!) rad tests are going on. Partial SVT replacement of modules already built,tested and soon ready in Pisa and UCSB is considered by 2005

3/20/03 SLAC- B DayMarcello A. Giorgi35 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 Terminology: 19 slots and 15 RPC layers RPC belt Slot18/19 5 brass layers (slot 8,10,12,14,16)

3/20/03 SLAC- B DayMarcello A. Giorgi36 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

3/20/03 SLAC- B DayMarcello A. Giorgi37 IFR Barrel Upgrade Decision on technology made during Dec Collaboration Meeting. Project based on LST will be ready (WBS) by end of may 2’’3 and will be reviewd in June. 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.

3/20/03 SLAC- B DayMarcello A. Giorgi38 PEPII – “adiabatic” scenario 0.5 ab x 10 34

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3/20/03 SLAC- B DayMarcello A. Giorgi41 A very promising physics program We have a and ambitious physics program until the end of this decade based on increase of of PEP II luminosity with a more aggressive scenario if the integrated luminosity would go well beyond 1/ab by the end of the decade.

3/20/03 SLAC- B DayMarcello A. Giorgi42 What after 2010 In B physics beyond 1- 2/ab? A lot of measurements but ?? Possibly yes!

3/20/03 SLAC- B DayMarcello A. Giorgi43 BACKUP

3/20/03 SLAC- B DayMarcello A. Giorgi44 Towards sin2  : B 0  A cp