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