Physics at BABAR and Future Plans

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					Physics at BABAR and Future Plans



         David B. MacFarlane
     for the BABAR Collaboration

        SLUO Annual Meeting
BABAR Collaboration
                  Gathering at SLAC, July 2002
 10 Countries
77 Institutions
593 Physicists
      May 2004




   July 6, 2004   D.MacFarlane at SLUO Annual Meeting   2
   B Factory Motivation: 1987

Discovering origins of CP violation
CP Violation in the B System

                                                         A1
   CPV through interference             B                          f
    of decay amplitudes

                                                                Ae i wk e i st
                                                                 2
                   wk
 B f                     wk
                                  B f                                           i  st 2
                                              (B  f )  A1  A2e   i wk
                                                                             e
              A2                                                                  i  st 2
                                             (B  f )  A1  A2e    i wk
                                                                              e
                            st
       A1                                       (B  f )  (B  f )
                                                for wk  0 and  st  0

    July 6, 2004          D.MacFarlane at SLUO Annual Meeting                               4
CP Violation in the B System



    CPV through interference                              i f

    of decay amplitudes
                                                ACP e
   CPV through interference
                                   B0                               fCP
    of mixing diagram
   CPV through interference      M 12                                  i f
    between mixing and decay                                     ACP e
    amplitudes                    ie 2i M          B0
                                   Directly related to CKM angles
                                     for single decay amplitude


    July 6, 2004    D.MacFarlane at SLUO Annual Meeting                          5
CKM Unitarity

Unitarity Condition: VudVub VcdVcb VtdVtb*  0
                          *       *
                                                                          Product of 1st
                                                                         and 3rd columns
                                                                         (1 of 6 relations)

                                    , 

                                                   VtdVtb
  VudVub
       
                                                              (1   )2   2e i 
             2   2e i                         VcdVcb

  VcdVcb
       
                                                             B 0 - B 0 mixing
         (b  u  )
                                                       
                   0, 0                                         1, 0 
                                  B and ( b  c  )
                     argVtd ;   argVub ;       
                                          *




   July 6, 2004             D.MacFarlane at SLUO Annual Meeting                          6
Time-Dependent Asymmetry Measurements

                                          
                            J/                            Exclusive
                                                                B Meson
                   Brec
                     0
                                                             Reconstruction
       4S                              KS0    
  e         e
                   Btag
                      0

 Y(4S) produces
coherent B pair:
    t  t                z ~ 260  m                         K
                                                             
                     Δt  Δ z/  βγ  c
                                                B-Flavor Tagging


   July 6, 2004      D.MacFarlane at SLUO Annual Meeting                      7
Ongoing BABAR Physics Program
 Comprehensively explore CP-violating asymmetries in
  B meson decays. Test the SM and search for CP-
  violating amplitudes from processes beyond the SM.
 Systematically map out rare B decay processes,
  including all those with sensitivity to new physics.
 Extract the magnitudes of CKM elements and other
  well-defined SM parameters.
   o   New physics processes exist in context of SM physics
   o   Requires detailed studies to elucidate the dynamics of
       processes and states involving heavy quarks.
 Perform studies over a broad range of physics, such
  as -lepton physics, QED studies, strong-interaction
  physics utilizing ISR processes, etc.

  July 6, 2004        D.MacFarlane at SLUO Annual Meeting       8
Ongoing BABAR Physics Program
 Comprehensively explore CP-violating asymmetries in
  B meson decays. Test the SM and search for CP-
  violating amplitudes from processes beyond the SM.
 Systematically map out rare B decay processes,
  including all those with sensitivity to new physics.
 Extract the magnitudes of CKM elements and other
  well-defined SM parameters.
   o   New physics processes exist in context of SM physics
   o   Requires detailed studies to elucidate the dynamics of
       processes and states involving heavy quarks.
 Perform studies over a broad range of physics, such
  as -lepton physics, QED studies, strong-interaction
  physics utilizing ISR processes, etc.

  July 6, 2004        D.MacFarlane at SLUO Annual Meeting       9
PEP-II Integrated Luminosity
PEP-II Records
Peak luminosity      9.21x1033            3x
                     cm-2 s-1             design
Best shift           246.3 pb-1
Best day             710.5 pb-1
Best 7 days          4.291 fb-1
Best week            4.200 fb-1
Best month           16.02 fb-1
Best 30 days         16.05 fb-1
BABAR logged         229.3 fb-1

                 ~230 million BB pairs
                                                              (as of July 4, 2004)
  July 6, 2004          D.MacFarlane at SLUO Annual Meeting                     10
BABAR Running Well




                                                            Production Month
                                                          Double Trickle




  ~103 million BB pairs in Run 4

  July 6, 2004      D.MacFarlane at SLUO Annual Meeting                        11
PEP II Luminosity Projections
                                                               1200                                                                                                 30


                                                                             Yearly Integrated Luminosity [fb-1]
                                                                             Cumulative Integrated Luminosity [fb-1]
                                                               1000                                                                                                 25
                                                                             Peak Luminosity [10**33]




                                                                                                                                                                         Peak Luminosity [10**33]
                                                                800                                                                                                 20
                               Integrated Luminosity ( fb-1)




                                                                600                                                                                                 15


                                                                                                                                                                    0.5 ab-1
                                                                400                                                                                                 10




                                                                200                                                                                                 5




                                                                  0                                                                                                 0
                                                                      1999    2000     2001     2002      2003     2004    2005    2006    2007    2008    2009

Yearly Integrated Luminosity [fb-1]                                    3       23        41       39       62.6    66.1    120.1   151     160.1   217      216
Cumulative Integrated Luminosity [fb-1]                                3       26        67      106      168.6    234.7   354.8   505.8   665.9   882.9   1098.9
Peak Luminosity [10**33]                                               1        2       4.4        5       7.5      10      13      16      20      22      25
                                                                                                                   Year


                                                                                                              2004 2006                                      1.6 x 1034
         July 6, 2004                                                         D.MacFarlane at SLUO Annual Meeting                                                                                   12
BABAR Publications
                                  BABAR*                    Belle
 <2003                                34                     54
 2003                                 47                     28
 2004 (July 1)                        18                     13
 Total                                99                     95

  * Labeled according to internal circulation date


 Expect 100th BABAR physics paper to be submitted this week




  July 6, 2004        D.MacFarlane at SLUO Annual Meeting           13
                                             Interference of b  c tree
                                                  decay with mixing
                             , 

   (b  u  )                 
                                            B 0 - B 0 mixing


                                                            CPV in B 0  J / KS0
               0, 0                                   1, 0 
                           B and ( b  c  )


       Revealing SM Physics: 2004
July 6, 2004            D.MacFarlane at SLUO Annual Meeting                     14
BABAR Result for sin2
                       CP = -1                              CP = +1




                                            sin2 = 0.723  0.158
  Summer 02      sin2β  0.741  0.067(stat)  0.033(syst)

  July 6, 2004        D.MacFarlane at SLUO Annual Meeting               15
Standard Model Constraints
                                                          Indirect constraints vs
                                                            direct measurement

                                                             At 95% CL:
                                                             19.4    26.5o
                                                              77    122o
                                                               37    80o




                 (sin2 WA  0.736  0.049               (stat  syst)



                                                             A.Hoecker et al.

  July 6, 2004      D.MacFarlane at SLUO Annual Meeting                         16
                                            Interference of suppressed
                                          b  s Penguin decay with mixing
                             , 

   (b  u  )                 
                                            B 0 - B 0 mixing


                                                                 CPV in B 0 
               0, 0                                   1, 0 
                                                                   KS0 ,  KS0 ,
                           B and ( b  c  )




July 6, 2004            D.MacFarlane at SLUO Annual Meeting                      17
Asymmetries for b  sss Penguins
B 0  K 0         W                               u-penguin CKM suppressed by ~0.02

                                                      Expectation
                    u , c ,t              s
       b                                       
                       0g                 s             SK  sin2 , CK  0
                   B                                        0
                                                            S
                                                                          0
                                                                          S

        d                                 s
                                          d
                                              KS0      Challenge

               “Internal Penguin”                      BF   7.61.2  0.5   10 6
                                                                 1.3




B 0  K 0                                                     “Tree-level bu”

                                                                                 
       B0                                              B0
                                           KS0                                     KS0
     BF  55.4  5.2  4.0   106                  u-tree CKM suppressed T/P < 0.1
    July 6, 2004               D.MacFarlane at SLUO Annual Meeting                       18
BABAR Results for B  KS                                       0


                                           B 0 tag                    BABAR
                                                                      110 fb1


                                           B 0 tag



Signal

N KS0         70  9



                                           SK  0.45  0.43(stat)  0.07(syst)
                                                0
                                              S
                   Submitted to PRL        CK  0.38  0.37(stat)  0.12(syst)
                                                0
    Summer 03                                  S



    July 6, 2004          D.MacFarlane at SLUO Annual Meeting                    19
 BABAR Results for B  f0KS                                   0


                                                  B 0 tag                    BABAR
         Total
         Continuum                                                           110 fb1
         All bgk.


                                                  B 0 tag
mES

                            Total
                       Continuum
                         All bgk.


                                                              0.56
m                                       SK  0.45 0.51
                                              0                             0.07(syst)
                                              S
                                                                  (stat)
      New: Winter 04                      CK  0.38  0.37(stat)  0.12(syst)
                                              0
                                              S


      July 6, 2004      D.MacFarlane at SLUO Annual Meeting                          20
Intriguing Hint?
    Present average
     for b  sss .

      0.42  0.12
    ~2.4 sigma below
   charmonium modes
                                                                 ~2.6s
                                                              discrepancy
   If central value
  remains as is, this
would become ~5 sigma
       by 2005




    July 6, 2004        D.MacFarlane at SLUO Annual Meeting            21
Asymmetries for b  sss Penguins
B 0  K 0         W                                          New physics in loops?

                    u , c ,t                                   b                  s
       b                                  s    
                       0g                 s                                            
                   B                                   B   0                      s
        d                                 s
                                          d
                                              KS   0
                                                                                  s
                                                                                       KS0
                                                               d                  d
               “Internal Penguin”
                                                               SUSY contribution with
B 0  K 0                                                         new phases

                                                             b                  s
                                                                                     
       B0                                                                         s
                                                       B   0

                                           KS  0
                                                                                  s
                                                                                       KS0
                                                               d                  d

    July 6, 2004               D.MacFarlane at SLUO Annual Meeting                           22
                                            Interference of suppressed
                                           b  u tree decay with mixing
                             , 

   (b  u  )                               CPV in B 0   ,  , ,
                                               B 0 - B 0 mixing

                                                
               0, 0                                   1, 0 
                           B and ( b  c  )




July 6, 2004            D.MacFarlane at SLUO Annual Meeting                  23
Competing Amplitudes for B  h+h-
    “Tree-level bu”             “Internal Penguin”                     Large
                   s                          s               BF (B 0  K   ) 
   CKM
                                                    K+        (18.5  1.0)  106
suppressed             K+
                                                                  Penguin dominated:
                            B0
                                                                  AK   2e i T  P
   B0                  -
                                                    -    Potential direct CPV and
                        Large                                 constraints on 
  Comparable                                                       Small
                   d                          d
                                                    +            BF (B 0     ) 
                       +                                         (4.8  0.5)  106
                            B0
                                                              |Penguin| ~ 0.3|Tree|
   B0                  -
                                                    - Complicates extraction of
                                    CKM                 from mixing induced CPV
                                 suppressed

    July 6, 2004            D.MacFarlane at SLUO Annual Meeting                          24
Observation of               B  
                                  0             0     0


   BABAR
    113 fb1
                                      signal
                                      qq bkgd
                                       +0



                                                       Fischer discriminant

                             Signal           BF x 10-6           s
                              14  2
               BABAR       46              2.1  0.6  0.3 4.2
                              13  3
                                9.3
                 BELLE     25.6            1.7  0.6  0.3 3.4         Summer 03
                                8.4
  July 6, 2004           D.MacFarlane at SLUO Annual Meeting                  25
Projections of       Isospin Analysis




 2006

 now




  July 6, 2004   D.MacFarlane at SLUO Annual Meeting   26
New Result on B                  0                  

Slong  0.19  0.33(stat)  0.11(syst)          BF (B0   0  0 ) 
Clong  0.23  0.24(stat)  0.14(syst)          2.1 106 (90% CL)

                             BABAR
       B 0 tag
                              113 fb1



      B 0 tag

                                             (96  10  4   stat   syst
                                                                             13   peng
                                                                                          
                                                                                          )


                                           o Isospin analysis: interference,
                                             NR contributions, I=1
   New: Winter 04                            amplitudes neglected
    July 6, 2004        D.MacFarlane at SLUO Annual Meeting                        27
Analysis from CKMFitter Group

                                             (no )




Other ingredients in  isospin analysis:
BR (    0 )  (26.4  6.4)106 [BABAR ,Belle] BR (  0  0 )  (0.620.60  0.12)106 [BABAR ]
                                                                       0.72


flong (    0 )  0.9620.065 [BABAR ,Belle]
                         0.049
                                                     flong (  0  0 )  1.0 [assumed]

     July 6, 2004              D.MacFarlane at SLUO Annual Meeting                           28
                                        Interference of color-allowed and
                                          color-suppressed tree decays
                             , 

   (b  u  )                 
                                            B 0 - B 0 mixing


                                                
               0, 0                                   1, 0 
                           B and ( b  c  )

                        sin2  : CPV in B 0  DCP K ,


July 6, 2004            D.MacFarlane at SLUO Annual Meeting            29
Method for sin               2

 Gronau-London-Wyler, 1991

                      A B   D 0K              DCP   K K  ,   
                                                     0

                                                     2A B   DCP K  
                                                                   0

      2A B   DCP K  
                  0


                                                          A B   D 0K  
                                                 st
                                                        Color-suppressed tree
                    A B   D 0K                   b  ucs VubVcs   3
                                                                   *


                    A B   D 0K  
                   Color-allowed tree
                                                   A B   D 0K  
                 b  ucs VcbVus   3 r 
                             *
                                                                              0.1  0.3
                                                   A B  D K
                                                                0   
                                                                         

  July 6, 2004        D.MacFarlane at SLUO Annual Meeting                            30
                                        Interference of b  c allowed and
                                          doubly-suppressed tree decays
                             , 

   (b  u  )                 
                                               B 0 - B 0 mixing

                                                
               0, 0                                   1, 0 
                           B and ( b  c  )

                        sin 2  +   : CPV in
                             B 0  D * , 

July 6, 2004            D.MacFarlane at SLUO Annual Meeting             31
Decays to Common Final States
                                      d             Ingredients
    VcbVud  
        *              2
                                               
                                                           Both B 0 and B 0 decay
           W                         u                     to D (*)  and D (*) 

     b                                c                    Sensitivity to  enters
                                                             via amplitude Vub
B   0
                                          D (*)           Mixing induced time-
        d                             d                   dependent asymmetries
                                                    Current status

VubVcd   4e i 
   *                                  d                             A B 0  D (*)  
                                          D (*)    D          
                                                                    A B  D
                                                                                                 0.02
                                                                                            
                                                         (*)
                                                                        0      (*) 
                                                                                       

                W      
                                      c                        from BF B 0  DS  
        b                             u                        and SU(3) symmetry

B0                                                 Typical errors
  d                                   d
                                                    s sin 2     0.6 for 80fb1
        July 6, 2004       D.MacFarlane at SLUO Annual Meeting                                     32
                             , 

                                
        (b  u  )                           B 0 - B 0 mixing

                                                
               0, 0                                   1, 0 
                           B and ( b  c  )

     Vub /Vcb

                                               Vcb
July 6, 2004            D.MacFarlane at SLUO Annual Meeting        33
Fully Reconstructed B Sample
    Old idea with new level
         of sensitivity

    Reconstruct B mesons in
         ~1000 modes

 B  D (*) , D (*) 0 , D (*) 3 ,etc                   S/B~0.3
        Efficiency ~0.4% or
       ~4000 B mesons/fb-1                        Require lepton p* > 1GeV/c
       (charged and neutral)

 Now
  ~900000 events tagged with
                                                          S/B~2.5
  fully reconstructed B meson
 By 2006          2,000,000 events


   July 6, 2004             D.MacFarlane at SLUO Annual Meeting                34
Study of b  u Enriched Sample




   167  21
signal events
          Vub   4.52  0.31(stat )  0.27(syst )  0.40(theo )   103
                         6.9%          6.0%            8.8%
     July 6, 2004        D.MacFarlane at SLUO Annual Meeting                35
HQE Fit Results for Combined Moments
                                                     ● = used, ○ = unused
                   mX moments                         in the nominal fit




                                                                     BABAR


 2/ndf = 20/15    Eℓ moments                             Red line: HQE fit
                                                     Yellow band: theory errors


    July 6, 2004      D.MacFarlane at SLUO Annual Meeting                     36
Measurement Improvements
 New BABAR result compares well with previous
  measurements




  o   |Vcb| is now measured to ±2%

  July 6, 2004      D.MacFarlane at SLUO Annual Meeting   37
                 Perspective: 2006

               Ready for next steps in
                 precision SM physics




July 6, 2004       D.MacFarlane at SLUO Annual Meeting   38
  Perspective: 2006

A Change of Paradigm?
Opportunities for Super B Factory
 Current program of PEP-II/BABAR and KEKB/Belle
  could attain ~1-2 ab-1 by end of the decade
  o   Data samples will be almost 10x larger than now and 50-200x
      times larger than CLEO
      o With such a large increase in sensitivity to rare decays,
        expect that there is a significant discovery potential
      o Rich program of flavor physics/CP violation to be pursued

 Even larger samples may offer opportunity to search
  for new physics in CP violation and rare decays
  o   High-luminosity asymmetric e+e- colliders with luminosities
      1035-1036 cm-2s-1 and up to 10 ab-1/year – “Super B Factory”
      o Emphasis on discovery potential and complementarity in an
        era when LHC is operating, along with LHCb and BTeV (?)
      o Complementary flavor physics if LHC discovers SUSY,
        etc; discovery window if no new physics seen?

  July 6, 2004       D.MacFarlane at SLUO Annual Meeting             40
Roadmap Process within BABAR
 Defining of physics case for Super B Factory
   o   Emphasize sensitivity to new physics in CP violation & rare
       decays
   o   Emphasize need & capability for precision SM measurements
 Requirements of viable project plans
   o   Peer review, approval and funding process
   o   Collider options and upgrade capabilities
   o   Detector capabilities & requirements in light of projected
       backgrounds
   o   Integrated scenarios for collider and detector construction,
       with implications for time to first data
 Projections of physics reach in light of competition &
  other opportunities
   o   Projections of samples and sensitivities; analysis of physics
       reach

  July 6, 2004         D.MacFarlane at SLUO Annual Meeting             41
Parameters for High-Luminosity B Factory
Luminosity          2-3x1034     1.5x1035 2.5x1035         7x1035    Units
e+                        3.1          3.1           3.5       8.0 GeV
e-                        9.0          9.0           8.0       3.5 GeV
I+                        4.5          8.7         11.0        6.8 A
I-                        2.0          3.0           4.8      15.5 A
(y*)                        7         3.6           3.0       1.5 mm
(x*)                      30            30           25        15 cm
Bunch length              7.5             4          3.4       1.7 mm
# bunches               1700          1700         3450       6900
Crossing angle               0            0         11        15 mrad
Tune shifts (x/y)         8/8       11/11        11/11       11/11 x100
rf frequency              476          476          476        952 MHz
Site power                 40            75           85       100 MW

     J.Seeman                       LER          +HER    +952 MHz rf
                                  vacuum      vacuum, IR
     July 6, 2004    D.MacFarlane at SLUO Annual Meeting                     42
Upgrade Plan: Initial 5x1035 Project
LER replacement

+ HER replacement

+ 952 MHz rf

SVT striplets                                                       Performance
                                                                        limit




Silicon outer tracker


Rad Hard EMC

DRC replacement

                                  2.5                         5.0          7.0 x 1035
    July 6, 2004        D.MacFarlane at SLUO Annual Meeting                       43
Upgrade Plan: Ultimate Reach
LER replacement

+ HER replacement

+ 952 MHz rf

SVT striplets

Thin pixels



Silicon outer tracker


Rad Hard EMC

DRC replacement

                                  2.5                         5.0   7.0 x 1035
    July 6, 2004        D.MacFarlane at SLUO Annual Meeting              44
  Possible Timeline for Super B Program

   Super-B              R&D, Design,                      Construction of              Super B
   Program              Proposals and                      upgrades to                Operation
                          Approvals                        L = 5-7x1035

                                                                                 Ldt ~ 10 ab-1/yr

2001      2003               2005 2006             2008          2010 2011 2012

                                                   Construction
                                                                 Installation
                              LOI     CDR
                                       P5                                             Commission

Planned PEP-II Program

           Ldt  140 fb
                        -1
                                 Ldt  500 fb-1                   Ldt ~ 1  2 ab-1
           (June 30, 2003)          (End 2006)                    (PEP-II ultimate)



       July 6, 2004             D.MacFarlane at SLUO Annual Meeting                           45
         Searching for New Physics
                          0.20                                        PEP-II, KEKB
                          0.19

                          0.18
                          0.17
                          0.16

                                                                                                                                                                                            Super B-Factory 10/2011
Error on sine amplitude




                          0.15
                          0.14
                          0.13
                                                                                                                                                                                                    5x1035 rising to 7x1035
                          0.12
                          0.11

                          0.10               f0KS
                          0.09
                                             KS0
                                              KS
                          0.08

                          0.07
                          0.06
                                             ’KS
                          0.05               KKKS
                          0.04
                          0.03
                          0.02                                       Discovery region if non-SM physics is 20% effect
                          0.01
                          0.00
                                 Jan-03



                                                   Jan-04



                                                                      Jan-05



                                                                                        Jan-06



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                                                                                                                                                                                                                                        Jan-14



                                                                                                                                                                                                                                                          Jan-15



                                                                                                                                                                                                                                                                            Jan-16
                                          Jul-03



                                                            Jul-04



                                                                               Jul-05



                                                                                                 Jul-06



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                                                                                                                                                                         Jul-10



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                                                                                                                                                                                                                                                 Jul-14



                                                                                                                                                                                                                                                                   Jul-15
                             July 6, 2004                                                          D.MacFarlane at SLUO Annual Meeting                                                                                                                                               46
Conclusions
 BABAR and PEP-II continuing along planned path
  towards ever higher luminosity
  o   Accumulating data with high efficiency, exploiting great strides
      by PEP-II; addressing known detector & computing issues
  o   Expect to accumulate 0.5 ab-1 in calendar 2006, representing a
      doubling of current data sample
  o   Strong physics case for doubling the data sample again by end of
      decade, achieving 1-2 ab-1
 BABAR has accumulated one of the great data
  samples in particle physics
  o   Physics is being vigorously exploited, both across a broad range
      of important problems, and broadly within the Collaboration
  o   Expect many new and updated results at ICHEP04, including
      results that use our full data sample from Run 4

  July 6, 2004       D.MacFarlane at SLUO Annual Meeting             47
Conclusions
 Have made good progress as a physics community in
  defining a longer-term roadmap
  o   Builds on ideas of Super B Factories from Snowmass 2001 and
      subsequent workshops
  o   Builds on proven track record of high-luminosity storage rings
      and general purpose e+e- detectors
  o   Builds on our present knowledge of CP violation and rare B
      decays; expect that case will only strengthen as we achieve
      planned luminosity improvements over the next few years
  o   Outlines now exist of the detector and collider requirements
      and goals for a major upgrade to existing facilities
 Next Steps: R&D, conceptual design development,
  sharpening physics arguments


  July 6, 2004       D.MacFarlane at SLUO Annual Meeting               48