1. University of Maryland
An overview of
BaBar physics & prospects
Hassan Jawahery
University of Maryland
SLUO meeting of Sept

2. Outline
A few comments on the status of the experiment.
A brief overview of impact of BaBar physics & the physics harvest of summer 2006
Outlook for the 1/ab phase.
The best and freshest results to be presented by Denis Dujmic later at this meeting and David Lange in his SLAC seminar on Wednesday.

3. The B factory: PEP II Machine & BaBar Detector
Operating at the U(4s) resonance

4. The BABAR Collaboration
USA [38/311]
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
Harvard U
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
INFN, Perugia & Univ
INFN, Roma & Univ "La Sapienza"
INFN, Torino & Univ
INFN, Trieste & Univ
The Netherlands [1/4]
NIKHEF, Amsterdam
Norway [1/3]
U of Bergen
Russia [1/13]
Budker Institute, Novosibirsk
Spain [2/3]
IFAE-Barcelona
IFIC-Valencia
United Kingdom [11/75]
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
U of Warwick
The BABAR Collaboration
11 Countries
80 Institutions
623 Physicists
Stanford U
U of Tennessee
U of Texas at Austin
U of Texas at Dallas
Vanderbilt
U of Wisconsin
Yale
Canada [4/24]
U of British Columbia
McGill U
U de Montréal
U of Victoria
China [1/5]
Inst. of High Energy Physics, Beijing
France [5/53]
LAPP, Annecy
LAL Orsay
LPNHE des Universités Paris
VI et VII
Ecole Polytechnique, Laboratoire Leprince-Ringuet
CEA, DAPNIA, CE-Saclay
Germany [5/24]
Ruhr U Bochum
U Dortmund
Technische U Dresden
U Heidelberg
U Rostock
Italy [12/99]
INFN, Bari
INFN, Ferrara
Lab. Nazionali di Frascati dell' INFN
INFN, Genova & Univ
INFN, Milano & Univ
INFN, Napoli & Univ
INFN, Padova & Univ
INFN, Pisa & Univ & Scuola Normale Superiore

5. End of the eventful Run 5- August 21
PEP II Reached 12.0x /cm2 /s
A heroic achievement.
Congratulations to the PEP II team!
BaBar collects ~96% of PEP II delivery

7. Partial composition of the data
BaBar Data: Runs 1-5
Partial composition of the data

8. Onward to the 1/ab data phase 2006-2008
Shutdown Aug 21 through Dec. 06-
PEP II Upgrade: Major upgrade to the machine to take the peak luminosity from 12x1033 /cm2/s  20 x1033 /cm2/s
(list from John Seeman)
BaBar:
Completing the upgrade of the Instrumented Flux Return (IFR)- replace RPC’s with LST’s in the remaining 4 sectors (2 sectors were done in 2002). Expect to fully recover (the slowly deteriorating) muon and KL identification capabilities of the detector.
Preparing for the expected higher data rate (and possibly higher background). Aims to stay at its usual very high efficiency of data collection (~96% historical average). Now studying the trigger and data flow system for possible bottlenecks and preparing for solutions.
Now in the third week of the shutdown and on schedule.

9. Future PEP-II Overall Parameters and Goals
A page from
John Seeman
Parameter
Units
Design
Present best
2007 goal I+ mA
2140
2900
4000 I-
750
1875
2200
Number bunches
1658
1722
1732
by* mm
15-20 10
8-8.5
Bunch length 15
11-12
8.5-9 xy
0.03
Luminosity
x1033 3
12.1 20
Int lumin in 24 hours
pb-1
130
911
1300
4 times design
7 times design

10. Onward to the 1/ab Phase of BaBar 2006-2008
Another page from John Seeman
Goal = 940 fb-1
2007
Down
2006
Down
Now

11. The physics reach of the BaBar Data
Just about any physics that is
accessible at
Charm Physics
Tau physics
Continuum e+e- hadrons
ISR: e+e- hadrons from threshold to ~5 GeV
CP Studies with B’s
& B Physics

12. Physics Harvest of summer 2006 Runs 1-5
   
Submitted 114 papers to the ICHEP 2006 in Moscow
   Measurements related to alpha (5 )
Measurements related to beta (14)
Measurements related to gamma (8)
Charmless B Decays (18)
B decays to open Charm (12)
Semileptonic B decays (10)
Radiative Penguin and Leptonic B decays (10)
Charmonium and Charm Spectroscopy (16)
Production and decay of Charm and Charmonium states (13)
Tau and low energy physics (8)
&
26 Invited Talks
[Some excerpts here]

13. The physics reach of the BaBar Data:charm
Charm physics with
Search for D0 mixing – highly suppressed in SM- a powerful window for NP searches
The Latest from BaBar
Observables:
CP even state: width G1 , mass m1 ;
CP odd state: width G2 , mass m2
y = (G1 - G2) / (G1 + G2) = DG / 2G
x = (m1 – m2) / G = Dm / G
D0 Mixing Still consistent with zero. Limits approaching the SM expectation

14. The physics reach of the BaBar Data: charm
More Charm physics with
Charm Spectroscopy: Keep finding New Charm Meson and Baryon states-
Testing ground for Lattice QCD: Measurements of decay constants fD, fDs, fD/ fDs & Form Factors are now emerging
= By validating LQCD, we may hope
for better knowledge of fB & (BB?)
, hence better knowledge of
|Vub|, |Vtd|, |Vts| & |Vtd|/ Vts|
Many engineering results of importance to B decays: e.g. measuring the phase and amplitude across several 3-body D meson Dalitz plots is critical for measuring angles g & b with B decays.
Our latest: Observation of a new excited charm baryon
Wc* ® Wc0 g
Wait for David Lange’s seminar for details
Wc* ® Wc0 g
FDs=248+/-15+/-6+/-31 MeV

15. The physics reach of the BaBar data: t decays
B factory data the primary source for searches for Lepton Flavor Violation (LFV) in t decays: Recent results on: tmg & teg - tmh & (Lepton and Flavor Violating decays) tLh highly suppressed in SM; (see David Lange’s talk for new BaBar results)
From Roger Barlow’s talk at ICHEP06
Example of how it impacts
Limits on Branching C.L
BaBar: Br(tmg)<0.68x10-7
Br(teg)<1.1x10-7
Belle: Br(tmg)<0.41x10-7
Br(teg)<1.2x10-7
Belle result
BaBar result
Excluded region

16. The physics reach of the BaBa: ISR
Hadron
Provides access to e+e- from
threshold to ~5 GeV
Allows for determination of R,
which goes into calculation of
muon g-2. So far has Measured:
.e+e ® pp, p+p-p-, 2p+2p-, K+K-p+p-, 2K+2K-, 3p+3p-, 2p+2p-p0p0, K+K-2p+2p-, K+Kp+p-, K+Kppf0
Discovery of New States- Y(4260), and further investigation of new states
Showing new structure
(2S)
N=125±23
(>8 σ)
This year’s new structure

17. The physics reach of the BaBar Data: B Decays
B Physics [with the ]
Investigation of CP violation in B meson Decays & tests of the CKM paradigm
Is the CP symmetry broken in B decays?
Can we fit the CPV effects in the CKM picture?
Is there room for New Physics?
Search for New Physics in rare (SM suppressed-FCNC) decays ?
B Decays dynamics: Tests of QCD predictions

18. A brief history of major milestones in B physics
The 1/ab phase: Precision tests of the CKM paradigm- Search for N.P. using loop dominated B decays, LFV tau decays, DD(bar) mixing …
109--
Precision sin2b; a & g measured; CKM over-constrained and established as the primary source of observed CPV in nature. Data consistent with no NP effects in b-d and sd.
108--
2001- CPV in B decays observed. Sin2b consistent with SM
107--
#B’s
1999- B Factories start operation.
1993-Radiative penguin bsg observed; Major constraint on models of New Physics;Rare decays BKp and pp obserevd; Role of gluonic penguins established;
B factory projects launched.
106--
105--
1987-B0 mixing & Vub measured; Lower bound on m(top)>42 GeV; with non-zero Vub, CKM in the game as a source of CPV
104--
1981-B meson observed

19. The Latest on the CKM test:
Theorist view of CKM Observables
The view from the experiments a g
Picture from A. Hoecker

20. Check for New Physics contribution
From
J. Charles @
FPCP 2006
Vancouver, Ca
Check for New Physics contribution
Back

21. Any room for New Physics contributions?
The analysis by the UTfit collab. allows NP amplitude and phase: [ Hep-ph/ ]
SM solution
CBd=1 & fBd=0
Non –SM solution is now essentially excluded. Limits on Semileptonic asymmetry (Asl) from BaBar & D0

22. New sources of CP violation in bd & sd are strongly constrained.
The message from New Physics Fits to CKM observables (As presented at LP2005- by L. Silvestrini) –
New sources of CP violation in bd & sd are strongly constrained.
New Physics contributions to the bs transitions are much less constrained & are in fact well motivated by models explaining large mixing angles in neutrino sector- bR tL bL W sL L
Possible New Physics presence can alter the observables from SM expecations

23. fcp f The “sin2bpenguin” Test:
Mixing induced CP violation in penguin modes b->sqq B0
fcp B0
For fcp =from b->sqq
Within the SM:
Dominant amplitude (~l2)- same phase as b->ccs f
suppressed amplitude (~l4)
Expect within SM
Sf~ -hcpsin2b
With new physics and new phases, Sf could depart from -hcpsin2b
The Task: Measure DSf=-hcpSf – sin2b & search for deviation from zero
A Key Question: How well do we know DSf within the SM?

24. ~ 2.5 s deviation at this point.
Expected DS with SM
More details in Denis Dujmic’s talk
Simple average: Spenguins=0.52 +/ vs reference point: sin2b=0.68+/-0.03
~ 2.5 s deviation at this point.
Eagerly waiting for more data

25. bsg- & bsl+l- - well established venues for NP searchesbR tL bL W sL L
Measured rates consistent with SM:
BF(b→sg)TH = 3.57 ± 0.30 x 10-4 (SM NLO)
BF(b→sg)EXP = 3.55 ± 0.26 x 10-4 (HFAG) D0
But there is more handles in these channels
Photon polarization in bgsL (g left-handed in SM)
Direct CP violation – nearly zero in SM
In BKll- q2 dependence of the rate; FB asymmetry, polariztion
Search for NP modification of Wilson coefficients C7, C9, C10
b-d g is now also established by BaBar & Belle
BaBar’s limit on Bpll

26. Tests with bsl+l- [BK*l+l- ]
Probe deviation of wilson coefficients., C7, C9, C10 from SM
FT = 1 – F0
Zero point of AFB a probe of NP influence
K* pol. FL
C7 = -C7(SM)
Wrong sign C9C10 excluded
Cannot exclude opposite sign C7 yet
C9C10 = -C9C10(SM)

27. + Tests with Direct CP violations
Direct CP violation results when several diagrams, with different cp conserving and cp breaking phases contributing to the same final state, interfere:
BKp: (K+ p- , K0 p+ , K0 p0 , ..)
E.g. BKp: +
A contributing diagram from “New Physics” can alter Acp from the SM values. But need predictions of Acp within SM- Again rely on QCDF or PQCD, or exploit symmetries (SU2, SU3 etc) to connect Acp in different modes and derive sum rules- to be tested.

28. Acp(B0K+p-)= -0.099+/- 0.016 Kp puzzle
Within SM: Expect Acp(b->sg) ~ 0
Another potential source of tension with SM
Acp(B0K+p-)= /
Kp puzzle
superweak is really out; to use as NP observable need reliable QCD predictions; Ample data to test & calibrate the calculations on.

29. Prospects for the CKM observables in the “1/ab” phase
(~ +1/ab from Belle)
Now
~7%
~30O
~11o
~0.04
Aiming for:
Also counting on improved systematics in most areas & help from the theory side
& s(Vtd/Vts)<4% (mostly from Tevatron).

30. Summary comments
There is an enormous amount of physics still to come from Flavor physics with BaBar in its “1/ab” phase. Two of the expected major outcomes are:
Precision knowledge of the charge weak sector of the SM & CKM parameters,
With the possibility of revealing deviation from the SM
Measurements of CP violation and decay properties in penguin dominated decay modes, with the possibility of revealing New Physics effects. Hints are already present in the current data.
[Given the large number of observables involved, a pattern may emerge showing evidence for New Physics. If we continue to see no deviation at these precisions- the results will likely serve as major constraints on the flavor structure of New Physics- to be seen at LHC.]
PEP II and BaBar are in preparation for the “1/ab” phase. Both upgrade efforts are proceeding well and on schedule.

31. Back up Slides On Prospects for CKM Observables

32. Measuring Vub= |Vub|e-ig
Higher precision on knowledge of Vub is absolutely essential- one of the main sources of tension in CKM tests
sin2 =0.791±0.034
from indirect determination
sin2=0.687±0.032
From direct measurement

33. Must resolve exclusive & inclusive discrepancy
Inclusive channels
Exclusive channels
~7% measurement now
Aiming for 5% accuracy
Must resolve exclusive & inclusive discrepancy

34. Measuring g: Vub= |Vub|e-ig
Decays involving interference of tree level bu & bc Processes. +
B-  (Df)K-
F=common to D0 & anti D0
Solve for g, & d=(,d1-d2) – rB=(|A1|/ |A2|)
f=DCP (Gronau-London-Wyler)(GLW method) (small asymmetry)
f=DCSD (Atwood-Duniets-Soni)(ADS Method) (additional problem of dD)
f= Dalitz analysis of D0->Ksp+p- (GGSZ) (combines features of GLW & ADS depending on the location in Dalitz plot)- the dominant method
[Giri, Grossman, Soffer, & Zupan, PRD 68, (2003),
Bondar (Belle), PRD 70, (2004)]

35. Measuring g: Vub= |Vub|e-ig
The method highly sensitive to rB:
fits favor rB ~ 0.1 (BaBar) ; rB >0.2 (Belle).
Main cause of the difference in errors
From the Dalitz Analysis alone:
g=(92+/  /- 12 )o (BaBar)
φ3=53°  3° 9°) Belle
Combined (UTfit): g = /- 30o
All methods
Error due to uncertainties in treatment of the DKspp-Dalitz plot (amplitudes and phases)
CLEO-c data can help. Projected error 3-5 deg
Future of g
rB=0.1
2008: 5-10o
Requires improvement in D-Dalitz model – from CLEO-c data and higher statistics tagged D* events at B factories

36. Measuring a: The prescription
Bp p: (p+ p-, p+ p0, p0 p0 )
Brp, B r r, …..
With Tree alone
But penguins (gluonic & E.W) can also lead to the same decays:
B->p0p0 sets the scale of the Da correction Da
Estimate Da by constructing the isospin triangle(Gronau & London)

37. Measuring a B(p+p0) = (5.75 0.42) B(p+p-) = (5.20 0.25)  10-6
A(p0p0) = 0.33
S(p+p-) =  0.09
A(p+p-) =  0.07
Br(Br+r-)=23.5+/- 2.2+/- 4.1x10-6
Br(Br+r0)=16.8+/- 2.2+/- 2.3x10-6
Br(Br0r0)=1.16+/ /- 0.27x10-6
S= /
C= / /- 0.06
Longitudenal polarization fraction dominate (~90%)
A=-C
Good news for a: A very lucky angle!
Longitudinal polarization dominates-CP even & small B->r0r0 compared to B->r+r0 , B->r+r-  suppressed penguin contributions-

38. Other ways of estimating penguin effects
Measuring a
BaBar: at 68% c.l.
(Brr, pp, rp) (WA)
Already the error is systematic (theory) dominated.
At ~2/ab, expect s(a) ~ 7o - 10o depending on the size of B->r0r0 .
Measuring B->r0r0 & its Time-dependent CP asymmetry will shrink errors further.
Other ways of estimating penguin effects

39. Measuring sin2b:
Sin2b is a precision measurement now - the non-SM solution is essentially excluded B->J/yK* & B->D0h
No evidence for direct CP violation- consistent with dominance of one diagram only-
At 2/ab (together with Belle):
Expect another factor of 2 reduction of errors