1#

An overview ofBaBar physics & prospects

Hassan JawaheryUniversity 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 s) resonance

4#

INFN, Perugia & UnivINFN, Roma & Univ "La Sapienza"INFN, Torino & UnivINFN, Trieste & Univ

The Netherlands [1/4]NIKHEF, Amsterdam

Norway [1/3]U of Bergen

Russia [1/13]Budker Institute, Novosibirsk

Spain [2/3]IFAE-BarcelonaIFIC-Valencia

United Kingdom [11/75]U of BirminghamU of BristolBrunel UU of EdinburghU of LiverpoolImperial CollegeQueen Mary , U of LondonU of London, Royal Holloway U of ManchesterRutherford Appleton LaboratoryU of Warwick

USA[38/311]

California Institute of Technology

UC, IrvineUC, Los AngelesUC, RiversideUC, San DiegoUC, Santa BarbaraUC, Santa CruzU of CincinnatiU of ColoradoColorado StateHarvard UU of IowaIowa State ULBNLLLNLU of LouisvilleU of MarylandU of Massachusetts, AmherstMITU of MississippiMount Holyoke CollegeSUNY, AlbanyU of Notre DameOhio State UU of OregonU of PennsylvaniaPrairie View A&M UPrinceton USLACU of South Carolina

Stanford UU of TennesseeU of Texas at AustinU of Texas at DallasVanderbiltU of WisconsinYale

Canada [4/24]U of British ColumbiaMcGill UU de MontréalU of Victoria

China [1/5]Inst. of High Energy Physics,

Beijing

France [5/53]LAPP, AnnecyLAL Orsay

The BABAR Collaboration

11 Countries 80 Institutions623 Physicists

LPNHE des Universités Paris VI et VII

Ecole Polytechnique, Laboratoire Leprince-Ringuet

CEA, DAPNIA, CE-Saclay

Germany [5/24]Ruhr U BochumU DortmundTechnische U DresdenU HeidelbergU Rostock

Italy[12/99]

INFN, BariINFN, FerraraLab. Nazionali di Frascati dell'

INFNINFN, Genova & UnivINFN, Milano & UnivINFN, Napoli & UnivINFN, Padova & UnivINFN, Pisa & Univ & Scuola

Normale Superiore

5#

End of the eventful Run 5- August 21PEP II Reached 12.0x 1033 /cm2 /s

A heroic achievement.

Congratulations to the PEP II team!

BaBar collects ~96% of PEP II

delivery

6#

•

7#

BaBar Data: Runs 1-5

BB x100.4~ 9

cc x100.5~ 9

x100.4~ 9

ISR

qq e e

& -

Partial composition of the data

8#

• 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.

Onward to the 1/ab data phase 2006-2008

Now in the third week of the shutdown and on schedule.

9#

Future PEP-II Overall Parameters and GoalsA page from

John Seeman

Parameter Units Design Present best 2007 goal

I+ mA 2140 2900 4000

I- mA 750 1875 2200

Number bunches

1658 1722 1732

y* mm 15-20 10 8-8.5

Bunch length mm 15 11-12 8.5-9

y 0.03 0.05-0.07 0.06-0.075

Luminosity x1033 3 12.1 20

Int lumin in 24 hours

pb-1 130 911 1300

7 times design4 times design

10#

•

2007Down

2006Down

Now

Goal = 940 fb-1

Onward to the 1/ab Phase of BaBar 2006-2008

Another page from John Seeman

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

GeVs 10

CP Studies with B’s

& B Physics

12#

Physics Harvest of summer 2006Runs 1-5

   

Submitted 114 papers to the ICHEP 2006 in Moscowhttp://www-public.slac.stanford.edu/babar/ICHEP06_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]

13#

Charm physics with Search for D0 mixing – highly suppressed in SM- a powerful window

for NP searches

The physics reach of the BaBar Data:charm

cc x100.4~ 9

Observables:

CP even state: width , massm1 ;

CP odd state: width , massm2

y = -

x = (m1 – m2) / = m /

The Latest

from BaBar

D0 Mixing Still consistent with zero. Limits approaching the SM expectation

14#

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 with B decays.

The physics reach of the BaBar Data: charm cc x100.4~ 9

Our latest: Observation of a new excited charm baryon

c* c

0

Wait for David Lange’s seminar for details

c* c

0

489 55 signal

m m m

FDs=248+/-15+/-6+/-31 MeV

15#

B factory data the primary source for searches for Lepton Flavor Violation (LFV) in decays: Recent results on: eLepton and Flavor Violating decays) h highly suppressed in SM; (see David Lange’s talk for new BaBar results)

Belle result

BaBar result

Excluded re

gion

Limits on Branching ratios: @90% C.L

BaBar: Br(x10-7

Br(ex10-7

Belle: Br(x10-7

Br(ex10-7

The physics reach of the BaBar data: decays

Example of how it impacts

From Roger Barlow’s talk at ICHEP06

16#

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,22 K+K- 2K+2K-, 33 22K+K-22 K+K K+Kf0

• Discovery of New States- Y(4260), and further investigation of new states

(2S)N=125±23

(>8 σ)

The physics reach of the BaBa: ISR

Showing new structure

This year’s new structure

Hadron

17#

B Physics [with the ]

Investigation of CP violation in B meson Decays & tests of the CKM paradigmIs 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

The physics reach of the BaBar Data: B Decays

BB x100.4~ 9

18#

109--

1981-B meson observed

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

1993-Radiative penguin bs observed; Major constraint on models of New Physics;Rare decays BK and obserevd; Role of gluonic penguins established;

B factory projects launched.

1999- B Factories start operation.

2001- CPV in B decays observed. Sin2 consistent with SM

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 …

Precision sin2; & 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 sd.

108--

107--

104--

105--

106--

#B’s

A brief history of major milestones in B physics

19#

The Latest on the CKM test:

Picture from A. Hoecker

Theorist view of CKM Observables

The view from the experiments

20#

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/0509219]

0/ sin2

d d d

d

SM

B B B

S BCP

M C M

A J K

Non –SM solution is now essentially excluded. Limits on Semileptonic asymmetry (Asl) from BaBar & D0

SM solution

CBd=1 & Bd=0

22#

The message from New Physics Fits to CKM observables (As presented at LP2005- by L. Silvestrini) –

New sources of CP violation in bd & sd are strongly constrained. New Physics contributions to the bs transitions are much less

constrained & are in fact well motivated by models explaining large mixing angles in neutrino sector- d

bR

tL

bL

WsL

L

Possible New Physics presence can alter the observables from SM expecations

b ss

sd

g

, ,u c t

W

23#

mtCmtSftBftB

ftBftBtA

cpcp

cpcpcp

cossin))())((

))())(()(

00

00

B0

B0

ff

Within the SM:

The “sin2penguin” Test: Mixing induced CP violation in penguin modes b-

>sqq

fcp

b ss

sd

g

, ,u c t

0SK

0B, , ( )CPKK

W

Sf~ -cpsin2

][][ **utuusubctccscb

TPPVVTPPVVA Dominant amplitude (~ same phase as b->ccs

suppressed amplitude (~

Expect within SM

With new physics and new phases, Sf could depart from -cpsin2

The Task: Measure Sf=-cpSf – sin2search for deviation from zero

A Key Question: How well do we know Sf within the SM?

For fcp =from b->sqq

24#

Simple average: Spenguins=0.52 +/- 0.05 vs reference point: sin68+/-0.03

~ 2.5 deviation at this point.

Expected S with SM

Eagerly waiting for more data

More details in Denis Dujmic’s talk

25#

bsbsl+l- well established venues for NP searches

Measured rates consistent with SM:

BF(b→s)TH = 3.57 ± 0.30 x 10-4 (SM NLO)

BF(b→s)EXP = 3.55 ± 0.26 x 10-4 (HFAG)

bR

tL

bL

WsL

L

But there is more handles in these channels

•Photon polarization in bsL ( left-handed in SM)

•Direct CP violation – nearly zero in SM

•In BKll- q2 dependence of the rate; FB asymmetry, polariztion

Search for NP modification of Wilson coefficients C7, C9, C10

D0

b-d is now also established by BaBar

& Belle

BaBar’s limit on Bll

26#

Tests with bsl+l- [BK*l+l- ]

FT = 1 – F0

K* pol. FL

C9C10 = -C9C10(SM)

C7 = -C7(SM)

Probe deviation of wilson coefficients., C7, C9, C10 from SM

Wrong sign C9C10 excluded

Cannot exclude opposite sign C7 yet

Zero point of AFB a probe of NP influence

27#

• Tests with Direct CP violations

W

t

b sd ,

u

u

g

b uu

sd ,

W

Direct CP violation results when several diagrams, with different cp conserving and cp breaking phases contributing to the same final state, interfere:

++

E.g. BK: ..

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.

γδ |T

P|

) iδ|P|eiγ(|T|eA)iδ|P|eiγ(|T|eA

sinsin2)fΒΓf)ΒΓ

f)ΒΓ)fΒΓcpA

28#

Acp(B0K0.099+/- 0.016

Within SM: Expect Acpb-

>s

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

Another potential source of tension with SM

puzzle

29#

Prospects for the CKM observables in the “1/ab” phase

(~ +1/ab from Belle)

02.0)2sin

8)

105)

%5|)

o

o

ubV

& Vtd/Vts)<4% (mostly from Tevatron).

Aiming for: Also counting on

improved systematics in most areas & help from

the theory side

Now

~7%

~30O

~11o

~0.04

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 SMMeasurements 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 SlidesOn

Prospects for CKM Observables

32#

Measuring Vub= |Vub|e-i

Higher precision on knowledge of Vub is absolutely essential- one of the main sources of tension in CKM tests

sin2 =0.791±0.034from indirect determination

sin2 =0.791±0.034from indirect determination

sin2=0.687±0.032From direct measurement

sin2=0.687±0.032From direct measurement

33#

Inclusive channels

~7% measurement now~20% now. Not a useful cross check

for the inclusive approach- yet.

Exclusive channels

Aiming for 5% accuracy

Must resolve exclusive & inclusive discrepancy

34#

Measuring Vub= |Vub|e-i

b uW

sc

+

KDB 0

KDB 0

B- (Df)K-F=common to D0 & anti D0b

W

s

cu

Decays involving interference of tree level bu & bc Processes.

f=DCP (Gronau-London-Wyler)(GLW method) (small asymmetry)

f=DCSD (Atwood-Duniets-Soni)(ADS Method) (additional problem of D)

f= Dalitz analysis of D0->Ks(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)]

)(1])([ iBerKfDBA

)(1])([ iBerKfDBA

Solve for & , – rB=(|A1|/ |A2|)

35#

From the Dalitz Analysis alone:

=(92+/- 41 11 +/- 12 )o (BaBar)

φ3=53° +15-18 3° 9°) Belle

Measuring Vub= |Vub|e-i The method highly sensitive to rB:

fits favor rB ~ 0.1 (BaBar) ; rB >0.2 (Belle). Main cause of the difference in errors

Error due to uncertainties in treatment of the DKs-Dalitz plot (amplitudes and phases)

-CLEO-c data can help. Projected error 3-5 deg (@1/ab

Combined (UTfit): = 78 +/- 30o

All methods

Requires improvement in D-Dalitz model – from CLEO-c data and higher statistics tagged D* events at B factories

2008: 5-10o

Future of rB=0.1

36#

easuring The prescription

b uu

sd ,

W

…..

But penguins (gluonic & E.W) can also lead to the same decays:

W

t

b sd ,

u

u

g

2sin(&0

2**

**

SC

eVVVV

VVVV i

udubtdtb

udubtdtb

With Tree alone

iγeiδe|T

P|1

iγeiδe|T

P|1

2ieλ

00 ππππ~ BABA

ππ~

2

10BA

ππ2

10BA

000 ππBA

000 ππ~

BAππEstimate by constructing the isospin triangle(Gronau & London)

B->sets the scale of the correction

)eff

α2sin(2C1S&0C

37#

Good news for very lucky angle!

Longitudinal polarization dominates-CP even & small B->compared to B->, B->suppressed penguin contributions-

Measuring

.).%90(40|

(

(sin

0

0002

lc

BB

BB

o

oeff

LLeff BfBf

21||

)/()(sin0000002

B(+0) = (5.75 0.42)B(+-) = (5.20 0.25) 10-

6

B(00) = (1.30 0.21) A(00) = +0.35 0.33S(+-) = 0.59 0.09

A(+-) = +0.39 0.07

B(+0) = (5.75 0.42)B(+-) = (5.20 0.25) 10-

6

B(00) = (1.30 0.21) A(00) = +0.35 0.33S(+-) = 0.59 0.09

A(+-) = +0.39 0.07

Br(Bx10-6

Br(B)=16.8+/- 2.2+/- 2.3x10-6

Br(B)=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

38#

Measuring BaBar: at 68% c.l.

BWA)

Already the error is systematic (theory) dominated.

At ~2/ab, expect 7o10o depending on the size of B->

Measuring B-> its Time-dependent CP asymmetry will shrink errors further.

Other ways of estimating penguin effects

11993

]114,86[

39#

Measuring sin2

violationCPdirectCessccfcpforS

mtCmtSftBftB

ftBftBtA

cpcp

cpcpcp

;)mod(2sin

cossin))())((

))())(()(

00

00

Sin2is a precision measurement now - the non-SM solution is essentially excluded B->J/K* & 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

0

0

( ) +( )

S

L

cc Kcc K