Physics with BaBar 19992000 Data

1
An overview of BaBar physics prospects
Hassan Jawahery University of Maryland
SLUO meeting of Sept 11. 2006
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
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-B
arcelona 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
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 AM U Princeton U SLAC U of South Carolina
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 1033 /cm2 /s A heroic
achievement. Congratulations to the PEP II team!
BaBar collects 96 of PEP II delivery
6

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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 RPCs with LSTs 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.
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Future PEP-II Overall Parameters and Goals
A page from John Seeman
7 times design
4 times design
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Onward to the 1/ab Phase of BaBar 2006-2008

Another page from John Seeman

Goal 940 fb-1
2007 Down
2006 Down
Now
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The physics reach of the BaBar Data

• Just about any physics that is
• accessible at
• Charm Physics
• Tau physics
• Continuum ee- ?hadrons
• ISR ee- ?hadrons from threshold to 5 GeV

CP Studies with Bs B Physics
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Physics Harvest of summer 2006Runs 1-5
    Submitted 114 papers to the ICHEP 2006 in
Moscow http//www-public.slac.stanford.edu/babar/I
CHEP06_papers_temp.htm    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
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The physics reach of the BaBar Datacharm

• 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
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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 Langes
seminar for details
Wc Wc0 g
FDs248/-15/-6/-31 MeV
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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 Langes talk for
new BaBar results)
The physics reach of the BaBar data t decays
From Roger Barlows talk at ICHEP06
Example of how it impacts
Limits on Branching ratios _at_90 C.L BaBar
Br(t?mg)lt0.68x10-7 Br(t?eg)lt1.1x10-7 B
elle Br(t?mg)lt0.41x10-7
Br(t?eg)lt1.2x10-7
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The physics reach of the BaBa ISR
Hadron

• Provides access to ee- from
• threshold to 5 GeV
• Allows for determination of R,
• which goes into calculation of
• muon g-2. So far has Measured
• .ee? pp, pp-p-, 2p2p-, KK-pp-, 2K2K-,
  3p3p-, 2p2p-p0p0, KK-2p2p-, KK?pp-,
  KK?p?p???????????f0?????
• Discovery of New States- Y(4260), and further
  investigation of new states

Showing new structure
This years new structure
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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

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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--
Bs
1999- B Factories start operation.
1993-Radiative penguin b?sg observed Major
constraint on models of New PhysicsRare decays
B?Kp and pp obserevd Role of gluonic penguins
established B factory projects launched.
106--
1987-B0 mixing Vub measured Lower bound on
m(top)gt42 GeV with non-zero Vub, CKM in the
game as a source of CPV
105--
104--
1981-B meson observed
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The Latest on the CKM test

Theorist view of CKM Observables
The view from the experiments
a
g
Picture from A. Hoecker
20
From J. Charles _at_ 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/0509219

SM solution CBd1 fBd0
Non SM solution is now essentially excluded.
Limits on Semileptonic asymmetry (Asl) from BaBar
D0
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• 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-

Possible New Physics presence can alter the
observables from SM expecations
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The sin2bpenguin Test Mixing induced CP
violation in penguin modes b-gtsqq
B0
fcp
B0
For fcp from b-gtsqq
Within the SM
f
Dominant amplitude (l2)- same phase as b-gtccs
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?
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Expected DS with SM
More details in Denis Dujmics talk
Simple average Spenguins0.52 /- 0.05 vs
reference point sin2b0.68/-0.03 2.5 s
deviation at this point.
Eagerly waiting for more data
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b?sg- b?sll- - well established venues for NP
searches
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 BaBars limit on B?pll
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Tests with b?sll- B?Kll-
Probe deviation of wilson coefficients., C7, C9,
C10 from SM
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.
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Within SM Expect Acp(b-gtsg) 0
Another potential source of tension with SM
Acp(B0?Kp-) -0.099/- 0.016
Kp puzzle

• superweak is really out to use as NP observable
  need reliable QCD predictions Ample data to
  test calibrate the calculations on.

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• 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)lt4 (mostly from Tevatron).
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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.

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Back up SlidesOnProspects for CKM Observables
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Measuring Vub Vube-ig Higher precision on
knowledge of Vub is absolutely essential- one of
the main sources of tension in CKM tests
sin2? 0.7910.034 from indirect determination
sin2?0.6870.032 From direct measurement
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Inclusive channels
Exclusive channels
7 measurement now
Aiming for 5 accuracy Must resolve exclusive
inclusive discrepancy
34
Measuring g Vub Vube-ig
Decays involving interference of tree level b?u
b?c Processes.

B- ? (D?f)K- Fcommon to D0 anti D0
Solve for g, d(,d1-d2) rB(A1/ A2)
fDCP (Gronau-London-Wyler)(GLW method) (small
asymmetry) fDCSD (Atwood-Duniets-Soni)(ADS
Method) (additional problem of dD) f Dalitz
analysis of D0-gtKspp- (GGSZ) (combines
features of GLW ADS depending on the location
in Dalitz plot)- the dominant method Giri,
Grossman, Soffer, Zupan, PRD 68, 054018
(2003), Bondar (Belle), PRD 70, 072003 (2004)
35
Measuring g Vub Vube-ig
The method highly sensitive to rB fits favor
rB 0.1 (BaBar) rB gt0.2 (Belle). Main cause
of the difference in errors
From the Dalitz Analysis alone g(92/- 41
? 11 /- 12 )o (BaBar) f353 15-18 ? 3
?9) Belle
Combined (UTfit) g 78 /- 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
  (_at_1/ab

Future of g
rB0.1
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-gtp0p0 sets the scale of the Da correction
Da
Estimate Da by constructing the isospin
triangle(Gronau London)
37
Measuring a

• Br(B?rr-)23.5/- 2.2/- 4.1x10-6
• Br(B?rr0)16.8/- 2.2/- 2.3x10-6
• Br(B?r0r0)1.16/- 0.37/- 0.27x10-6
• S-0.19 /- 0.21 0.05-0.07
• C-0.07 /- 0.15/- 0.06
• Longitudenal polarization fraction dominate (90)

A-C
Good news for a A very lucky angle! Longitudinal
polarization dominates-?CP even small B-gtr0r0
compared to B-gtrr0 , B-gtrr- ? suppressed
penguin contributions-
38
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-gtr0r0 . Measuring
B-gtr0r0 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-gtJ/yK
B-gtD0h 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