BABAR Status & Plans David B. MacFarlane SLAC EPAC Meeting January 25, 2006.

BABAR Status & Plans

David B. MacFarlaneSLAC EPAC MeetingJanuary 25, 2006

Jan 25, 2006 BABAR Status and Plans 2

Pillars of BABAR physics program Highly constrained and redundant set of

precision tests of weak interactions in the Standard Model

Searches for physics beyond the Standard Model in a well understood & characterized environmento Sensitivity to New Physics at LHC mass scales

through rare decays and CP violationo Discovery potential from large data sample across

a whole range of beauty, charm, tau, two-photon, ISR physics

o Full program of flavor physics/CP violation measurements will provide a legacy of fundamental constraints on future New Physics discoveries

Challenging measurements at the edge of sensitivity benefit enormously from operation of both PEP-II &

KEK B Factories


The BABAR Collaboration

11 Countries 80 Institutions623 Physicists


BABAR & Belle physics results

BABAR Belle

Journal Papers 184 155

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-05

BaBar

Belle


Integrated data sample to date

96% efficiency over the entire history of

BABARBABAR, Run 5


Parameter Units Design Oct 2005

I+ mA 2140 2940

I- mA 750 1740

Number of bunches

1658 1732

y* mm 15-20 11

Bunch length mm 15 11-12

y 0.030.044-0.065

Luminosity x1033 3.0 10.0

Int lumi / day pb-1 130 727.8

PEP-II overall parameters and goals

More than 3x design

More than 5x design


Parameter Units Design Oct 2005 2007 goal

I+ mA 2140 2940 4000

I- mA 750 1740 2200

Number of bunches

1658 1732 1732

y* mm 15-20 11 8-8.5

Bunch length mm 15 11-12 8.5-9

y 0.030.044-0.065

0.054-0.07

Luminosity x1033 3.0 10.0 20

Int lumi / day pb-1 130 727.8 1300

PEP-II overall parameters and goals

30%

40%

10%

Factor 2!


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Projected data sample growthIn

teg

rate

d L

um

inosit

y [

fb-1]

12

17

20

Lpeak = 9x1033

o PEP-II: IR-2 vacuum, 2xrf stations, BPM work, feedback systems

o BABAR: LST installation

4-month down for LCLS, PEP-II &

BABAR

Double from 2004 to 2006

ICHEP06

Double again from 2006 to

2008 ICHEP08


IFR upgrade with LSTs

Bottom & top sextants installed summer 2004Remaining sextants delayed until fall 2006


Weak Interaction in Standard Model

Apex at

,

0 0B - B mixing

) B and ( b c

( ) b u

0,1 0,0

Unitarity Triangle as a summary of Standard Model

b physics

us ubud

cs cbcd

ts tbtd

V V VV V V V

V V V

+ phases

Radiative penguin decays

* * *Unitarity: 0ub cb tbud cd tdV V V V V V


Classic indirect constraints

ubV K

dm sm

2008: ~5%


Weak Interaction in Standard Model

Apex at

,

0 0B - B mixing

) B and ( b c

( ) b u

0,1 0,0

1

2

3

Unitarity Triangle as a summary of Standard Model

b physics

us ubud

cs cbcd

ts tbtd

V V VV V V V

V V V

+ phases

Radiative penguin decays

CP violation

* * *Unitarity: 0ub cb tbud cd tdV V V V V V

CKM elements & quark masses are fundamental constants

emerging from EW symmetry breaking


0 0/ SCPV in B J K

Interference of b c tree decay with mixing

CPV in charmonium modes

0- 0B Bmixing ( )b u

,

)B and ( b c 0,1 0,0

1

2

3

0Bb

db

d t

tWW 0B

0Bc

b

d

W/J

d

c

s 0K


0 , , ,

CPV in B

Interference of suppressed b u tree decay with

mixing

CPV in charmless modes

0- 0B Bmixing

( )b u

,

)B and ( b c 0,1 0,0

1

2

3

0Bb

db

d t

tWW 0B

0Bub

d

W

d

u

d

3rd component:

sizable Penguin diagram

0Bu

b

d

W

d

ud

g, ,u c t


Remarkably good progress on gamma!

0 , ,CP DCS: CPV in B D K D K

Interference of color-allowed and color-suppressed tree

decays

0- 0B Bmixing

( )b u

,

)B and ( b c 0,1 0,0

1

2

3

Bcb

u

W

(*)0Du

u

s(*)K

Bc

b

u

W(*)0D

u

u

s (*)K

Effect depends on ratio of two diagrams

( ) decay to common fi nal state

D D

0 0, , SCP DCSD D D K


Direct CP violation measurements

sin2

cos2

2008: ~2% 2008: 10o

2008: 5-10o


UT from sin2 & indirect constraints

Paradigm change!

Now: looking for New Physics as

correction to CKM

Overconstrained: growing set of independent measurements are consistent

with CKM picture


UT from CP violation measurements alone

New B Factory milestone:

Comparable UT precision from CPV in B decays alone

Overconstrained: subsets of

measurements can be used to test for

new physics


0 0 0 , , S SCPV in B K K

Interference of suppressed b s Penguin decay with

mixing

CPV in Penguin Modes

0- 0B Bmixing ( )b u

,

)B and ( b c 0,1 0,0

1

2

3

0Bb

db

d t

tWW 0B

0Bs

b

d

W

0Kd

ss

g, ,u c t

Another implication of overconstrained:

redundant approaches to same CKM

parameter


Potential New Physics contributions

0B

b ss

sd

d

W

g

, ,u c t

“Internal Penguin”

0SK

0B

0SK

0 0 B K

0 0 B K

0SK

0B

b

s

s

sd d

0SK

0B

b

s

s

sd d

SUSY contribution with new phases

New physics in loops?


Revealing new physics

LHC

B Factory

Squark mass matrix (d sector)


Summary after summer 2005 updates

: 237 million pairsBelle: 386 million pairs

BABAR BBBB

No sign of Direct CP

2.4 between CP violation in s-

penguin vs sin2 (cc)

Summer 05 results

About 0.5 loss vs Winter 2005 due to shift in charmonium average

Charmonium

s-Penguins


BABAR CKM physics goalsPhysics Impact FY2006

450 fb-1

FY2007650 fb-1

FY20081000 fb-1

Precision measurement of sin2

Fundamental constant of the SM, whose precision is only limited by statistics

Improve error by factor of two to 2%

Precision measurement of CP asymmetry in penguin modes

Primary approach to new physics in loop decays; presently discrepant with SM predictions at 2.4 level when averaged over all available modes

Potentially reach the 4-5 level for average of all modes

Could reach the 4-5 level for individualtheoretically-clean modes

Precision measurement of unitarity angle

Fundamental constraint on the UT

Discovery of if it has SM branching fraction

Isospin analysis in allows better than 10o measurement

Precision measurement of unitarity angle

Fundamental tree-level constraint on phases and amplitudes originating from any new physics beyond the SM

Pioneering measurements with 10-15o accuracy

Determine to 5-10o precision

Precision measurement of with inclusive & exclusive semileptonc B meson decays

Fundamental tree-level constraint on amplitudes and phases originating from any new physics beyond the SM

Inclusive decays reach 6.5% precision

Exclusive decays reach 8% precision

b sqqb sss

b sss

0 0 0B B

ubV


Global CKM fit: 2008

( ) 6.5% ubV ( ) 5%sm (sin 2 ) 0.019 o( ) 8 o( ) 10

95% contours


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0.40Jan-03

Jul-03

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Jul-07

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Jul-08

Jan-09

Jul-09

Err

or

on

sin

e am

pli

tud

eProjections to summer 2008

K*

5 discovery region if non-SM physics is 0.30 effect

2004=240 fb-1

2008=1.0 ab-1

Golden modes reach 5

sigma level

Projections are statistical errors only; but systematic errors at few percent

level

Luminosity expectation

s:

20082004

( ) 0.30S

f0KS

KS0

KS

’KS

KKKS


now

( ) 6.5% ubV

2008

UT constraints in 2008

Assumption: no NP in trees [almost any NP model]

95% contours

Significant constraint on all New Physics models in LHC era

( ) 8% ubV


Bounds on new physics in Bd mixing

now

2008

Model independent

Mass scale being probed

for unit coupling:

(now) ~ 5 TeV(2008) ~

10TeV

0/ sin2

d d d

d

SM

B B B

S BCP

M C M

A J K

Introduce new physics in mixing

diagram


BABAR rare decay physics goals

Physics Impact FY2006450 fb-1

FY2007650 fb-1

FY20081000 fb-1

Discovery of Provides a determination of and constrains Higgs sector in MSSM and NP in a parameter regime that is complementary to LHC

Limit First hints Discovery if it has SM branching fraction

Precision determination of branching fraction, CP asymmetry, and photon energy spectrum

Loop diagram that provides unique insight into B meson structure and constrains Higgs sector in MSSM and NP in a parameter regime that is complementary to LHC

Ultimate precision on photon energy spectrum

Strong constraints from 5% error on BF; 1-2% error on CP asymmetry

Precision determination of branching fractions, CP and FB asymmetries

Contributions from Z-penguin and W-exchange loops that give additional constraints on MSSM and NP in a parameter regime that is complementary to LHC

Useful precision for constraints on NP

Strong constraint for NP from BF, CP and FB asymmetries

Discovery of Provides a unique determination of CKM matrix elements ; likely before mixing discovery

First hints Discovery if it has SM branching fraction

Precise measurement of BF

b s

b s

ubVB

B

/td tsV V0 0-S SB B


New CKM constraints in sight

B

B

b

W

td

W,H

b

u

2008: Possible discovery Possible discovery: 2007


Complementarity with LHC

today

2008

Approx…

2HDM

Constraints from B , B s


BABAR Physics GoalsPhysics Impact FY2006

450 fb-1

FY2007650 fb-1

FY20081000 fb-1

Search for mixing

Highly suppressed in the SM and therefore an ideal place to search for new physics in charm mixing diagram

Hint if 1% mixing amplitude

Discovery if 1% mixing amplitude

Search for lepton-flavor violation in or other tau decays

Expected to be significantly enhanced in many extensions of the SM accommodating neutrino mass, but extremely small in the SM itself

Limits reach 2x10-8 sensitivity

New discovery in heavy hadron spectroscopy

Improved understanding of QCD in non-perturbative regime

Discoveries possible anytime



0 0-D D


Lepton-flavor violation & mSUGRA

tan= 55Inverted hierarchy

s- i

s LS

P

allo

we

d

Br(e) < 1x10-8

2x10-85x10-8

11x10-8

Current BABAR limit

2008 limit


Summary: Physics plans for BABAR Goal for 2005-2006: double current data set

o Delay in Run 5 can be overcome by summer 2006 with extended running period, with substantial reduction in errors on CP violation asymmetries in rare decay modes

o Error on average of Penguin modes should reach 0.06 Goal for 2007-2008: double again to ~1 ab-1

o Individual Penguin modes with errors in range 0.06-0.12o Suite of fundamental Standard Model measurements with

substantially improved levels of precision

Beyond 2008 might offer exciting opportunities if New Physics has been seen by B Factories & LHC

o Sensitivity to New Physics through rare decays, CP violation, & large data sample with a significant discovery potential

o Full program of flavor physics/CP violation measurements provide fundamental constraints on future New Physics discoveries

Backup Slides


A day in the life of a B Factory


Peak PEP-II Luminosity (x1E33) per Month

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PEP-II performance: peak luminosity


BABAR Detector

DIRC PID)144 quartz

bars11000 PMs

1.5T solenoid

EMC6580 CsI(Tl) crystals

Drift Chamber40 layers

Instrumented Flux Return

Iron / Resistive Plate Chambers or Limited

Streamer Tubes (muon / neutral hadrons)

Silicon Vertex Tracker

5 layers, double sided strips

e

(3.1GeV)

e (9GeV)

Collaboration founded in 1993Detector commissioned in 1999


DCH electronics upgrade Motivation:

o Remove anticipated deadtime problem due to serialization and shipping of data from DCH to readout module

Upgrade in two steps:o Phase 1 (summer 2004): L1 to

~4kHz• Reduce ADC payload (3216

bytes) from front ends with no impact on dE/dx performance

o Phase 2 (Oct 2005) : L1 to ~5kHz• Larger FPGA to allow feature

extraction on DCH endplate• New boards installed in Oct

down, ready to activate FPGA code

BABAR Status & Plans David B. MacFarlane SLAC EPAC Meeting January 25, 2006.

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Transcript of BABAR Status & Plans David B. MacFarlane SLAC EPAC Meeting January 25, 2006.