Matter-Antimatter Asymmetries and CKM Parameters in BABAR

Jeffrey D. RichmanJeffrey D. RichmanUniversity of California, Santa BarbaraUniversity of California, Santa Barbara

Meeting of the Particle Physics Program Prioritization Panel (P5) Oct. 6, 2005

Representing the BRepresenting the BAABBARAR collaboration collaboration

Version 3.0

Outline Outline Where are we in B physics? A high-precision, benchmark measurement: sin2 from BJ/ K0

: a work in progress A path to |Vcb|, |Vub|, heavy-quark masses, and QCD parameters Perspective and conclusions

• Zoltan Ligeti (theory): discussion of theoretical issues & uncertainties; new physics

• Luca Silvestrini (theory): new physics sensitivity• Riccardo Faccini: BABAR measurements related to new physics and

rare decays, including sin2 from bs penguin modes

Long B lifetimeMAC, Mark II (1983)

Exclusive B decaysCLEO (1983)

B0B0 oscillationsARGUS (1987)

BXu l and Vub

ARGUS, CLEO (1990)

Observation of BK* CLEO II (1993): Loops!

BD* l and Vcb

ARGUS, CLEO, LEP, Isgur, Wise +…(>1989): HQET!

Some notable or surprising measurements:

The Current Era in B Physics

First achievement: clear and unmistakable evidence for large (order unity) CP violation in the B meson system.

Amazing stream of surprising results and new methods. Many of these would not have appeared in an extrapolation from the past.

Detector technology: can search for essentially any type of B decay. Trigger on all events; Tracking/Vertexing + CsI + PID

Dramatic advances in our knowledge of the CP-violating phase structure of quark interactions.

0 0 0B

0 0SB K

0B 0 *0 0 0

SB K K

0 0 0/ ( ) SB J K 0 (limit)B

(limit)B

(2317)scc D X(4.26)ISRe e Y

0 0( )SB D K K s, p wave

*ud ubV V

*td tbV V2 ( )

1 ( ) 3 ( )

Probing the CKM quark mixing matrix

• Angles of triangle: measure from CP asymmetries in B decay• Sides of triangle: measure rates for bul, B0B0 mixing• Other constraints in plane from CP violation in K decay

0 0 oscillation rateB BuB X

cB X

0 0 0( ) SB B cc K

0 0

0 0

0

/

/ (GLW)

(ADS)

( ) (Dalitz)

CP

S

B D D K

D D K

K K

K K

0 0 + -( ) , , B B

*cd cbV V

0 0B

0 0 oscillation rates sB BB

*B D

0 0 0( ) SB B ss K0 0( ) ( )B B ccdd

CP asymmetry from interference between mixing and decayCP asymmetry from interference between mixing and decay

2

2 2

12 Im( ) 1 1

S C

1 Im , 0S C 1 decay amplitude, |q/p|=1:

0* *212 12

0212 12

iCP f

ifCP

f H B AM qM p Af H B

/ 1

1 decay amp: magnitude & strong phase divide out!

0.008 0.037 0.018

1.0013 0.0034qp

HFAG

BABAR, PRD 70, 012007 (2004)

sin2sin2as a precision measurementas a precision measurement

The ccs sin2 determination belongs to a special class of definitivemeasurements in particle physics.

1. We can achieve high statistical precision before we are limited by systematic uncertainties.

2. It is a data-driven measurement, with very little dependence on Monte Carlo or theoretical assumptions.

3. Theoretical uncertainties <1%, so its interpretation is clear (and powerful) [Ligeti, Silvestrini]

0B 0 0 0,S LK K K

1 / , (2 ), , c cJ S

*0 0 0SK K

BBAABBARAR sin2 sin2from charmonium (227 M BB)from charmonium (227 M BB)

sin2 = 0.722 0.040 (stat) 0.023 (sys)

J/ψ KL (CP even) mode(cc) KS (CP odd) modes

(after raw asymmetry shown above is corrected for the dilution)

asymmetry is opposite!

|| = 0.950 +/- 0.031 (stat) +/- 0.013 (sys)

PRL 94, 161803 (2005),(hep-ex/0408127)

hypothesis test

Foundations of the sin2Foundations of the sin2 measurement measurement

0 decay (tag)B

t > 0t < 0

0 0( ) ( ) SB t cc K 0 0( ) ( ) SB t cc K

t resolution function Background

Si detector alignment, beam spot

e e

MES (GeV)

Mistag rates= w(tag)

1 2D w Mixing asymmetrylog scale

t t

1.6 ps 1/4 mm

Signal: 7,730 events (all modes)Control: 72,878 events [D(*) ,a1,J/K*]

t=tt=trecrec-t-ttagtag fits to fits to BFlavBFlav control sample control sample

Unmixedevents

Mixed events

Unmixed events

Mixed events

(ps)rec tagt t t

linear scale log scale

log scale

linear scale

Mistag (Mistag (ww) measurement from ) measurement from BFlavBFlav oscillation oscillation data data

T=2mD=(1-2w)<1 due to mistags

mixNoMix( ) Mix( )( )NoMix( ) Mix( )

t tA tt t

-10.502 ps (fixed to PDG'04)m Separatelydetermine Dfor each tagcategory.

/

( ) 1 1 2 cos ( )4

Bt

Unmixed dMixed B

ef t w m t R t

=1.6 ps

(74.9 0.2)% 2(1 2 )

=(30.5 0.4)% Q w

Overall taggingperformance:

Systematic Errors for sin(2)Category (sin2)

226 BB

(sin2) at

1 ab-1 (est.) Background shape & CP content of peaking background

0.012 0.004 to 0.006

Mistag differences between BCP and Bflav samples 0.007 0.003

Composition and content of J/ KL background 0.011 0.005 to 0.009

t resolution and detector effects: silicon detector alignment and t resolution model

0.011 0.004 to 0.008

Beam spot position 0.007 0.004 to 0.007

Fixed md, B, , || 0.005 0.002

Tag-side interference DCSD decays 0.003 0.003MC statistics, bias 0.003 0.001TOTAL 0.023 0.01 to 0.016

Some systematics scale with 1/sqrt(N); other partially do.

sin2sin2 uncertainties vs. integrated luminosity uncertainties vs. integrated luminosity

Currentsystematicuncertainty

Range ofestimatedsystematicerror: 1 ab-1

(109)

At 1 ab-1, we can improve sin2 by nearly a factor of 2.

A work in progress A work in progress

W

b ud d

u

ubV

d0B

Original idea for measuring Works if B0+- amplitude is dominated by the bu tree process.

2 2 2i i iCP

Aq e e ep A

2

2 2

12 Im=sin2 0

1 1S C

If penguins were negligible, we could extract directly from the time-dependent CP asymmetry for B0+- with no additional information.

The penguin problem in The penguin problem in BB0 0 ((BB0 0 ))

b u

d

u

d

0B d

b

d ud

udubV ,...tdV

• In 1998, CLEO performed a search for charmless two-body B decays. Did not observe B0+- , but found large B0+- rate [CLEO, PRL 80, 3456 (1998)].

• We cannot ignore penguin amplitude in B0+-. (In fact, P-T interference produces direct CP violation in B0+- and may also in B0+-).

21 sin 2 S C

We still measure S and C, but S isn’t sin2!0C

Use I-spin invariance of hadronic matrix elements to relate Bamplitudes. Assume that pions are identical particles.

b bd d

u uuu u u d

dB

0

0

Penguins: I=1/2 only, so no contribution to B++0 .

trianglerelations

I-spin solution to the penguin problemI-spin solution to the penguin problem [Gronau & London, PRL, 65, 3381 (1990)]

amplitudes cancel

0 0 0 0 012

( ) ( ) ( )A B A B A B 0 0 0 0 01

2( ) ( ) ( )A B A B A B

0 12

uu dd

B++0 is pure tree (no gluonic penguin)triangles have common side after rescaling one set by exp(2i):

Constraining Constraining with I-spin relations with I-spin relations

0 0A A

12

A

00A00A

12

A

2

0 0 2 0( ) ( ) ( )iA B A B e A B

• If penguin amp=0,triangles coincide.

• 4-fold discrete ambiguity (can flip both triangles)• take worst case as

“penguin error”

0 0 0 0 0 02

0 0

( ) ( )sin( ) ( )

B B B BB B B B

Grossman & Quinn, PRD 58, 017504 (1998)

Measurements ofMeasurements of B B00, , BB00, and , and BB++++00

0 0 0B

0B

0B 1.17 0.32 0.10

Mode B/10-6 (BABAR)

5.8 0.6 0.4

5.5 0.4 0.3

00 amp.isn’t smallcompared tothe others.

0 0 0B

0.12 0.56 0.06

B/10-6 (Belle)0.4 0.20.5 0.32.3

5.0 1.2 0.5

4.4 0.6 0.3 0 0C

BABAR

35 (90% C.L.)

Red triangles: B+ and B0 decaysPurple triangles: B- and B0 decaysDifference: CP violating interference between T and P amplitudes.

BABAR PRL 94, 181802 (2005)

0 0 0

6

( )

1.1 10

B B

Bigger than

Huge program on B decays to charmless hadronic final states...

BABAR, PRL 94, 131801 (2005)

(10-6)

The investigation of The investigation of BBBABAR has made intensive effort to study the B modes:

• Measurement of B++0 , B0 00 limit [PRL 91, 171802 (2003).]• 1st observation of B+- and polarization measurement [PRD 69, 031102 (2004)]• First time-dependent CP asymmetry measurement and confirmation of polarization. [PRL 93, 231801 (2005)]• Updated time-dependent CP asymmetry measurement with Run 1-4 data. [hep-ex/0503049 PRL] • Limit on B000 branching fraction [PRL 94, 131801 (2005)]

0 0 0B

0B

0B 30 4 5

Mode B/10-6 (BABAR)

6523 6

1.1 (90% C.L.)4732 7

B/10-6 (Belle)

3.84.124.4 2.2

[230 M ]BB

[89 M ]BB

[89 ]BB

[85 M ]BB

[275 M ]BB

14 (90% C.L.) (compare with 35 for )B BABAR, PRL 94, 131801 (2005)

0B

00

Measurement of CP asymmetry for BMeasurement of CP asymmetry for B

232 M

BB ̅B0 tags

Is the system in a CP eigenstate?If not, get effective dilution of CP asymmetry.

t (ps)

Angular analysis almost pure CP=+1 !

0, 1

B0 tags

BBAABBARAR BELLE (LP2005)BELLE (LP2005)

ffLL

SSCC

029.0033.0031.0039.0951.0

021.0029.0014.0978.0

08.014.024.033.0

08.042.009.0

09.018.003.0 09.010.030.000.0

BABAR, PRL 95, 041805 (2005)

Would like to see S, C with 5x data!

: combining the : combining the BBAABBARAR measurements measurementsB B

[29º;61º] excluded @ 90% C.L.

α = 100º 13º

79º< α <123º @ 90% C.L

PRL, 94, 181802 (2005) PRL 95, 041805 (2005)

(deg)

2717113 ( ) 6 ( )stat sys

hep-ex/0408089

B Dalitz 10

9103

CKM fitexcluding measurements

(deg) (deg)

1

1- C.L

.

Projections for Projections for measurement in B measurement in B++--

Current measurementfrom B

Projected measurementsfrom Bfor 1 ab-1

The uncertainty on dependscritically on B(B).Scenarios:1. use current central value2. +13. - 1

+1

B(B00)unchanged

-1

Multiple unresolved solutions within each peak.

190% C.L.

Critical issue for Critical issue for measurement: measurement: BB0000

I-spin triangle for B(current measurements)

Projected 2 uncertainties on Projected 1 uncertainties on

Goals and issues for the Goals and issues for the programprogram

BBResolve issues with S and C: Belle observes significant direct CP violation in B; BABAR doesn’t.

BABAR and Belle values of B00 are higher than theoretical expectations (and differ by x2) and are not precisely measured.

BBComplicated Dalitz-plot measurement; currently disfavors one of the solution regions allowed from B. Will this hold up with more data?

BBNeed to observe B00. Value is critical in constraining the I-spin triangle and determinining penguin-induced uncertainty on .

Is I-spin conserved? Does the triangle close?

Non-resonant background: studies indicate is small effect but more data would allow more detailed investigation.

Improve measurements of S and C…also investigate Ba1+

A path to A path to

b c

u

us

u

2cbV A

*usV K

0D

iubV e

* 1csV

b

u

uc

su

0D

K

How can we get interference? Need D0 f and D0 f. (Compare with B0J/ K0.) Some observations:

1. Uses charged B decays; method is based on a direct CP asymmetry. Issues: strong phase , rB=|A(bu)/A(bc)| =0.1-0.2

2. Uses tree diagrams: no loops/mixing diagrams, no penguin/new physics issues. Together with |Vub|, gives CKM test with trees only.

0( ) BA B D K A 0 ( )( ) iB BA B D K A r e

color suppressed

(GLW method):(GLW method): B B--DDCPCPKK--, , DDCPCPffCPCP

D0 (D0 ) fCP = CP eigenstate from singly-Cabibbo-suppressed decay. [Gronau & London, PLB 253, 483 (1991), Gronau & Wyler, PLB 265, 172 (1991)].

+1 ,CP K K 0 0 0 0 0 01 , , , ,S S S S SCP K K K K K

W

c du

d

u

ucdV

*udV

W

c du

d

u

u

*cdV

udV

0D 0D

0( ), 1 Bi

D B D BDAmp B CP A r e

Large rate, butinterference is small: rB << 1

(ADS method): BB- - [ [ DD00KK++--; ; DD00KK++--]]KK--

0 0; B D K D K

0 0; B D K D K i

ubV e

bu

uc

su

0Dc su

d

u

u

0D

K

K

CFDB

u

b cu

s

u0D c d

u

u

u

K K

B DCSD s

( ), D Bi iB D D BA B D K A A r e r e

Interference is large: rB, rD comparable, but overall rate is small!

Atwood, Dunietz, & Soni, PRL 78, 3257 (1997),PRD 63, 036005 (2001)

(Dalitz plot): BB- - [ [ DD00KKss -- ;; D D00 KKss -- ]]KK--, ,

Interference depends on Dalitz region: (CP), (DCSD)

Giri, Grossman, Soffer, & Zupan, PRD 68, 054018 (2003),Bondar (Belle), PRD 70, 072003 (2004)

2m 0 D

),(),()(),( 2222022

mmfeermmfKDBAmmM ii

BB

2 2 0 2 2 2 2( , ) ( ) ( , ) ( , )Bi iBM m m A B D K f m m r e e f m m

|M|2 =

0 D

B

B

( )BiBr e

2m

2m2m

Relatively large BFs; all charged tracks; only 2-fold ambiguity.

2 2 0 2( )Sm m K

0 0Sf K *f K

Fitting the Fitting the DD00KKSS++-- Dalitz plot Dalitz plot

Nevts = 82 KPurity: 97%

BABAR

2 2 0( )Sm m K 2 2 0( )Sm m K

Use continuum dataD*+D0+ (91.5 fb-1)

DCS K*(892)

(770)

CA K*(892)

2/dof3824/3022=1.27

hep-ex/0504039

Issue: contribution of broad, s-wave resonances(1) Orig. method: 2 BWs(2) New: K-matrix

Anisovich & SaratevEur. Phys. J A16, 229 (2003)

BB+/+/DD00KK+/+/ KKS S ++-- Dalitz plot distributions Dalitz plot distributions B+D0K+ BD0K

B+D0K+ BD0K

Differences between B+ and B signifies direct CP violation.Good S/B, but needs more data.

Above, D0 is super-position of D0 and D0

: : BBAABBARAR and Belle results (Dalitz method) and Belle results (Dalitz method)BBAABBAR AR (+stat+sys+model) Belle Belle (+stat+sys+model)

rrB B ((DD00KK))

rrB B ((DD**00KK))

rrB B ((DD00KK*)*)

direct CP direct CP

significancesignificance

0.21 0.08 0.03 0.04

0.160.110.12 0.02 0.04

0.25 0.18 0.09 0.04 0.08

(68 15 13 11) (67 28 13 11)

non-K*

0.12 0.08 0.03 0.04

0.17 0.10 0.03 0.03

0.50 (0.75) @ 1 (2 )

Importance of rB …

Br

( ) (degrees)

0.1 0.2

The error on is very sensitiveto the value of rB. Other methods(ADS, GLW) help us to measurerB.

2.32.4

hep-ex/0504039, 0507101 hep-ex/04110439, 0504013

rB measurements from ADS channels

Most measurements using interference with DCSD D0 decay indicate rB<0.2.

Projected uncertainty on Projected uncertainty on for for rrBB = 0.1 = 0.1

We will be able to improve the error on by at least a factor of 2.

Projected syserror due to D0 Dalitz plot

,cb ubV V

Surprises in semileptonic Surprises in semileptonic BB decays decays

b, c u

• Two complementary experimental and theoretical approaches Exclusive decays: measure (and predict) the rate for specific exclusive modes, usually in restricted region of phase space. Inclusive decays: use as much of phase space as possible to minimize theoretical input. Extract non-perturbative QCD parameters from data. Goal: |Vij

| (exclusive) = |Vij| (inclusive)!

B* **

, , ,...D D D:b c

:b u1, , , , , ,...a

||VVcbcb|| and the atomic physics of and the atomic physics of BB mesons mesons

2 52

3

3 3 3 32 2 2

34 4

0 2 2 3

( ) (1 ) ( , )192

( ) 1 2(1 ) ( ) (1/ )2

F bSL c cb ew pert

D LS D LSG G

Db bb

b b b

G mB X l V A A r

m mz r r d r O mm m m

/c br m m

s

s

3exp HQE th

exp HQE

exp HQE

exp HQE

(41.4 0.4 0.4 0.6 ) 10

(10.61 0.16 0.06 )%

(4.61 0.05 0.04 0.02 )GeV

(1.18 0.07 0.06 0.02 )GeV

cb

c

b

c

V

m

m

B

Extract |Vcb |, quark masses, and non-perturbative QCD parameters from measured inclusive lepton-energy spectrum and hadron recoil mass spectrum (masses, QCD params given below: “kinetic scheme”). Yields |Vcb | to about 2%. (lattice QCD goal: 3% for BD*l)

s

s

s

s

2 2exp HQE

2 2exp HQE

3 3exp HQE

3 3exp HQE

(0.45 0.04 0.04 0.01 )GeV

(0.27 0.06 0.03 0.02 )GeV

(0.20 0.02 0.02 0.00 )GeV

( 0.09 0.04 0.07 0.01 )GeV

G

D

LS

Benson, Bigi, Mannel & Uraltsev, hep-ph/0410080BABAR, PRL 93, 011803 (2004)

chromomagnetic expec value

kineticexpectationvalue

Darwin termspin-orbit

Gambino & Uraltsev, Eur.Phys.J. C34, 181 (2004)

Why measuring |Why measuring |VVub ub | is hard| is hard

BABAR (hep-ex/0509040)

bu

continuum data (off res)

bc subtraction

BBrecoreco

BBrecoilrecoil

XXuu ll

ee--

DD**

ee++

( )0.1 2%( )

ub u

cb c

V B XV B X

Lepton spectrum endpoint analysis Fully reconstructed B recoil analysis

Large bc background; suppression cuts introduce dependence on theory predictions for kinematic distributions.

BABAR

||VVub ub |: inclusive measurements|: inclusive measurements• Key CKM constraint

• Use mb and QCD parameters extracted from inclusive BXc l and BXs spectra.• Many methods with uncertainties around 10%. • Uncertainty from mb has been reduced to 4.5%.• With more data, the |Vub| uncertainties could be pushed down to 5%-6.5%.

2 2ub

cb

VV

mX vs. q2

Eℓ endpoint

mX

Eℓ vs. q2

3WAvg

(4.38 0.19 0.27) 10ubV expt mb, theory

uq

2 2maxq q

uq

2 2minq q

HPQCD: hep-lat/0408019

Fermilab/MILC: hep-lat/0409116

f+(q2) is relevantform factor forB l l=e

HPQCD

Fermilab/MILC

restricted q2 range

At fixed q2, lepton momentum spectrum is exactly known in this mode, since only one form factor.

2q

BB00 l l-- form-factor predictions form-factor predictions

Measuring |Measuring |VVubub| using | using BB ll and lattice QCDand lattice QCD

Experiment vs. Lattice: Experiment vs. Lattice: DDKK ll form factorform factor

Measuring |Measuring |VVubub| using | using BB ll

BABARProjection to 1 ab-1 (data taken to be on BK fit curve from present measurement).PRD 72, 051102 (2005)

In the high q2 region alone, we will measure the branching fraction with an uncertainty of (6-7)% , or (3-3.5)% uncertainty on |Vub |. Lattice theorists expect to reach 6%, so exclusive/inclusive will be similar.

Perspective/ConclusionsPerspective/Conclusions

Parameter Goals for 1 ab-1 Methods

sin2sin2

Measure sin2Measure sin2 to +/- 0.025 or to +/- 0.025 or bettter.bettter.

tt-dependent CP asymmetry -dependent CP asymmetry measurements; measurements; t resolution and t resolution and mistags measured in datamistags measured in data

Understand Understand BB, , BB, , BB decays. Measure decays. Measure to 8-16 degrees to 8-16 degrees (depends on (depends on BB). ).

tt-dependent CP asymmetry -dependent CP asymmetry measurements + isospin analysis of measurements + isospin analysis of related modes; related modes; BB appears to be the appears to be the most powerful.most powerful.

Understand Understand BB++DD KK++ decays; decays; measure measure to 9 degrees or better to 9 degrees or better (depends on (depends on rrBB).).

Direct CP (Direct CP (tt-independent) measurement; -independent) measurement; determine strong phases & relative determine strong phases & relative amplitudes from data. amplitudes from data. DD00 Dalitz-plot Dalitz-plot analysis+(analysis+(DD00CP) +(CP) +(DD00DCSD); also DCSD); also measure sin(2measure sin(2++

|V|Vub ub || Understand inclusive Understand inclusive BBXXcc ll , , inclusive inclusive BBXXuu l l , and , and BB l l ; ; measure |measure |VVubub| to 6.5% or better.| to 6.5% or better.

InclusiveInclusive: determine heavy-quark : determine heavy-quark parameters from kinematic distributions; parameters from kinematic distributions; ExclusiveExclusive: : ll at high at high qq2 2 + lattice QCD. + lattice QCD.

Four major measurement programs related to determining the valuesof fundamental Standard Model CKM parameters.

Perspective/ConclusionsPerspective/ConclusionsMany measurements are now multidimensional: extract not only thequantity of interest, but also critical information that is difficult to get from theory. Examples:

• and measurements are data-driven: isospin triangle, rB, etc.• b-quark mass and other QCD parameters are now well determined from Vcb studies; this information is used as input for

the Vub measurement.

CKM measurements go hand-in-hand with other parts of the BABAR physics program:

• Enormous program of hadronic rare B decay studies• Search for departures from CKM pattern using bs decays

• Studies of electroweak penguin and leptonic decays • Charm physics, including searches for mixing and CP violation. These are great ideas and measurements: this is a great physics

program!

Backup slidesBackup slides

CP Asymmetries: formulas and definitionsCP Asymmetries: formulas and definitions

2f f

f 2 2f f

1 λ 2 Im(λ )( ) exp( ) cosh 2 Re(λ ) sinh cos( ) sin( )2 2 1 λ 1 λ

f t tt t m t m t

2f f

2 2f f

1 λ 2 Im(λ )( ) exp( ) 1 cos( ) sin( )1 λ 1 λ

f t t m t m t

0( )B bd

0B

CPfno net oscillation

net oscillation 0B

0( )B bd CPfno net oscillation

0B0Bnet oscillation

0( ( ) )phys CPB t f 0( ( ) )phys CPB t f

For <<1,

Behavior of time-dependent CP asymmetriesBehavior of time-dependent CP asymmetries

Linear scale

Log scale

Non-exponentialdecay law for a specific final state!

Angles of the unitarity triangleAngles of the unitarity triangleConsider two complex numbers z1 and z2.

1

2

1 1

2 2

i

i

z z e

z z e

2 1( )2 2

1 1

//

iz ze

z z 2

2 11

arg zz

*ud ubV V *

td tbV V

*

cd cbV V

*

*arg td tb

ud ub

V VV V

*

*arg cd cb

td tb

V VV V

*

*arg ud ub

cd cb

V VV V

The CKM matrix and its mysterious patternThe CKM matrix and its mysterious pattern

212

2

3

3

2 412

2

1 ( )1 ( )

(1 ) 1

0.97 0.23 0.004 0.23 0.97 0.04 (magnitudes only)

0.004 0.04 1

ud us ub

cd cs cb

td ts tb

V V V A iV V V A OV V V A i A

• The SM offers no explanation for this numerical pattern.• But SM framework is highly predictive: Unitarity triangle: (Col 1)(Col 3)* =0 etc. Only 4 independent parameters: A, One independent CP-violating phase parameter

(Wolfenstein parametrization)

Comments on Comments on BB physics history (see slide 3) physics history (see slide 3) Exclusive B decays: Reconstruction of Exclusive B decays: Reconstruction of bbcc modes requires charm meson modes requires charm meson

reconstruction. The product branching fractions for reconstruction. The product branching fractions for BBDD(*)(*)X, DX, D(*)(*)K(nK(n modes are typically of the order 10modes are typically of the order 10-4-4 to 10 to 10-5-5, so large data samples are , so large data samples are needed. The 1needed. The 1stst exclusive B signal from CLEO was made by summing over exclusive B signal from CLEO was made by summing over several different modes.several different modes.

Long Long B B lifetime: showed that lifetime: showed that VVcbcb was smaller than expected. We began to was smaller than expected. We began to see the larger pattern of the CKM matrix outside the 2x2 Cabibbo sector: see the larger pattern of the CKM matrix outside the 2x2 Cabibbo sector: VVcbcb is proportional to is proportional to , not , not This measurement also demonstrated the This measurement also demonstrated the critical importance of high-precision tracking and provided a strong critical importance of high-precision tracking and provided a strong impetus to the development of Si vertex detectors.impetus to the development of Si vertex detectors.

BBBB oscillations: this critical discovery was made by ARGUS. The oscillations: this critical discovery was made by ARGUS. The oscillation period is about 12.6 ps (6.3 ps for maximal probability to oscillation period is about 12.6 ps (6.3 ps for maximal probability to oscillate), which is about 8x larger than the mean decay time of 1.6 ps. CP oscillate), which is about 8x larger than the mean decay time of 1.6 ps. CP violation in mixing is a very small effect in B decays, since the off-shell violation in mixing is a very small effect in B decays, since the off-shell intermediate states such as tt completely dominate over on-shell intermediate states such as tt completely dominate over on-shell intermediate states. CP violation requires interference between these two intermediate states. CP violation requires interference between these two paths. This simplifies the BABAR/Belle CP violation measurements, which paths. This simplifies the BABAR/Belle CP violation measurements, which are based on a different effect: the interference between mixing and decay are based on a different effect: the interference between mixing and decay amplitudes.amplitudes.

Comments on Comments on BB physics history (see slide 3) physics history (see slide 3) Observation of charmless semileptonic Observation of charmless semileptonic BB decays by ARGUS and CLEO decays by ARGUS and CLEO

was a critical discovery. The measured value of was a critical discovery. The measured value of VVubub//VVcbcb maps out an maps out an annular region in the annular region in the plane. The consistency between this region and plane. The consistency between this region and the the BBBB mixing and mixing and KK regions provided an early test of the CKM regions provided an early test of the CKM framework. In the framework. In the VVubub measurement, the lepton spectrum endpoint region measurement, the lepton spectrum endpoint region was used, because backgrounds from was used, because backgrounds from bbclcl decays are suppressed decays are suppressed compared with compared with bbulul, where the lepton can be more energetic. Later , where the lepton can be more energetic. Later measurements use a variety of techniques to increase the phase space measurements use a variety of techniques to increase the phase space region used and to thereby decrease theoretical uncertainties. region used and to thereby decrease theoretical uncertainties.

The observation of The observation of BBKK** by CLEO was a major discovery, by CLEO was a major discovery, demonstrating the presence of loop processes at the rate expected in the demonstrating the presence of loop processes at the rate expected in the SM. SM. BBAABBARAR/Belle are studying a very large number loop processes in both /Belle are studying a very large number loop processes in both exclusive and inclusive measurements. These processes provide a powerful exclusive and inclusive measurements. These processes provide a powerful probe of physics beyond the SM through virtual effects.probe of physics beyond the SM through virtual effects.

VVcbcb measurements were given a strong boost by the development of Heavy measurements were given a strong boost by the development of Heavy Quark Effective Theory (HQET). This and subsequent theoretical Quark Effective Theory (HQET). This and subsequent theoretical advances have substantially improved our understanding of the dynamics advances have substantially improved our understanding of the dynamics of of BB decays. decays.

A simplified picture of the CKM matrix

β

-i

-i

γ1 11 1 1

1 1

e

e

u

d

t

c

bs

3

Largest phases in the Wolfensteinparametrization

Magnitudes of CKM elements

Note: all terms in the inner product between columns 1 and 3 are of order 3. This produces a unitarity triangle of roughly equal sides.

11

1

1

sin2sin2measurement: signal modesmeasurement: signal modes

CP sampleCP sample NNTAGTAG puritypurity ηηCPCP

J/ψ KS (KS→π+π-) 2751 96% -1

J/ψ KS (KS→π0π0) 653 88% -1

ψ(2S) KS (KS→π+π-) 485 87% -1

χc1 KS (KS→π+π-) 194 85% -1

ηc KS (KS→π+π-) 287 74% -1

Total for ηCP=-1 4370 92% -1J/ψ K*0(K*0→ KSπ0) 572 77% +0.51

J/ψ KL 2788 56% +1Total 7730 78%

MES (GeV)

yield

ΔE (MeV)

J/ψ KL signalJ/ψ X backgroundNon-J/ψ background

BABAR

yieldsignal region

signal region

signal region

yield

MES (GeV)

Control samples for sin2Control samples for sin2

BFlav sampleBFlav sample NNTAGTAG puritypurity

DD-- ++/a/a11++ (6 decay modes) (6 decay modes) 3297432974 83.1%83.1%

D*D*-- ππ++//ρρ++/a/a11++ (12 decay modes) (12 decay modes) 3500835008 89.4%89.4%

J/J/ψψ K K*0*0(K(K*0*0→ K→ K++ππ--) (2 modes)) (2 modes) 48964896 95.8%95.8%

TotalTotal 7287872878

MES (GeV) MES (GeV)

Use neutral B control sample (“BFlav”) to determine tagging dilution and t resolution parameters from simultaneous fit to the data.

Tagging algorithm performanceTagging algorithm performance

(%)(%) w(%)w(%) w(%)w(%) Q(%)Q(%)LeptonLepton 8.6+/-0.18.6+/-0.1 3.2+/-0.43.2+/-0.4 0.2+/-0.80.2+/-0.8 7.5+/-0.27.5+/-0.2KaonIKaonI 10.9+/-0.110.9+/-0.1 4.6+/-0.54.6+/-0.5 0.7+/-0.90.7+/-0.9 9.0+/-0.29.0+/-0.2KaonIIKaonII 17.1+/-0.117.1+/-0.1 15.6+/-0.515.6+/-0.5 0.7+/-0.80.7+/-0.8 8.1+/-0.28.1+/-0.2K-K- 13.7+/-0.113.7+/-0.1 23.7+/-0.623.7+/-0.6 0.4+/-1.00.4+/-1.0 3.8+/-0.23.8+/-0.2 14.5+/-0.114.5+/-0.1 33.9+/-0.633.9+/-0.6 5.1+/-1.05.1+/-1.0 1.7+/-0.11.7+/-0.1OtherOther 10.0+/-0.110.0+/-0.1 41.1+/-0.841.1+/-0.8 2.4+/-1.22.4+/-1.2 0.3+/-0.10.3+/-0.1TotalTotal 74.9+/-0.274.9+/-0.2 30.5+/-0.430.5+/-0.4

(sin 2) 1Q

Measure of tagging performance Q: Q=(1-2w)2

Lepton category not sensitive to mistag differences due to

DCSD decays

New Belle result (summer 2005)

1sin(2 ) 0.652 0.039 0.020 0.010 0.026 0.036C

J/ψ KL (CP even) modeJ/ψ KS (CP odd) mode

386 MBB

Belle-CONF-0569hep-ex/0507037

BBAABBARAR and Belle Systematic Errors and Belle Systematic Errors(for aficionados)(for aficionados)

BABAR,bccs modesonly

Belle, bccs and bsssmodes

sin2sin2 results from charmonium: summary results from charmonium: summaryfrom Kazuo Abe’s talk at LP05

backup slide

backup slide

BABAR and Belle time-dependent CP BABAR and Belle time-dependent CP asymmetry results for asymmetry results for BB00

Belle observes significant direct CP violation in B0+-.

BABAR-Belle: 2.3

Asymmetry for direct CP violationAsymmetry for direct CP violation

1 1 2 2

1 1 2 2

( ) ( )1 2

( ) ( )( ) ( )1 2( )

i i

i P fi i

A A e A e

A A e A e e

2 2

1 2 1 22 2 22

2 21 2 1 2

1 1

2sin( )sin( )Asymmetry

2cos( )cos( )

A A

A A A AA A

Problems with interpreting measurements of direct CP asymmetries: 1. We often don’t know the difference 1-2 , so we cannot

extract 1-2 from the asymmetry without additional information.2. We often don’t know the relative magnitude of the interfering

amplitudes.

Direct CP violation in BDirect CP violation in B00KK--BB00KK++

0

0

9

696

10

n B K

n B K

6( ) 227 10N BB

Bkgd symmetric!

696 910 0.133696 910

A

5( ) 2 10B B K

0.133 0.030 0.009KA

The tree-penguin interference that is bothering us in B0shows up spectacularly as direct CP violation in B0K+.

a short digression…

: direct measurement vs. CKM fit: direct measurement vs. CKM fit

11-12[CKM fit] (96 )

Combining Combining measurements of measurements of

12-9(99 )

B CP(t) asymmetrydisfavors mirror solution

inferred fromother CKM measurements

Sensitivity to Sensitivity to across the Dalitz plot across the Dalitz plot

Monte Carlo

from from BBDKDK (all methods) (all methods)

151263meas

71357CKM

BB--DDCPCPKK--, , DDCPCPffCPCP (GLW) Fit Results (GLW) Fit Results

GLW method: GLW method: DD decays to CP eigenstates decays to CP eigenstates

3 unknowns: , , rB

4 observables (3 independent relations)In principle can solvefor everything! (Just need a lot of data.)Don’t yet observe significant asymmetries.

ADS method

Note: both the B and D diagrams are different now two strong phases (but they combine)

Two observables4 unknowns: , rB, rD, =B+D

30

20 (3.9 0.6) 10D

B D Kr

B D K

Need one more observable: measure another D final state: (same B but different D. Now have: , rB, B+D1, B+D2

Basically a good method, but no significant signals yet!

BB--DDCPCPKK--, , DDCPCPffCPCP (GLW) Fit Results (GLW) Fit Results

B l

q2 distribution fromvarious experiments

Branching fraction measurements, includingrestricted q2 region.

The CKM Triangle Using Angles OnlyThe CKM Triangle Using Angles Only