David Hitlin Quinn Symposium April 16, 2010 1 Experiments on CP Violation in B Meson decay David Hitlin Matter and Antimatter: Fact and Fancy April 16,

David Hitlin Quinn Symposium April 16, 2010 1

Experiments onExperiments onCPCP Violation in Violation in BB Meson decay Meson decay

David HitlinMatter and Antimatter: Fact and Fancy

April 16, 2010


The CP problem(s)

She has been a member of the BABAR Collaboration since (before) its inception

Her insight has been brought to bear on a variety of important problems concerning CP violation measurements, which I will refer to as we proceed

She also was co-editor of theBABAR Physics Book

CP violation in the strong interactions is weak, while CP violation in the weak interactions is strong Helen Quinn has played a role in both these problems

, and co-author of a mystery thriller


The CKM Matrix In 1973 Kobayashi and Maskawa realized that

extending Cabibbo’s two generation mixing matrix that relates the quark mass eigenstates to the weak eigenstates to a third generation introduced a phase that could account for CP-violating effects first seen in decay in 1964

“Hadronic engineering” issues did notallow a quantitative comparison of the phase in theory and experiment

Bigi and Sanda proposed that CP –violating asymmetries in B0 decays to CP eigenstates could be directly related to theoretical quantities

In 2001 BABAR and Belle measured the CP asymmetry in decays,showing that the CKM phase could account for the observation and leading to the award of the 2008 Nobel Prize to Kobayashi and Maskawa

ud us ub

cd cs cb

td ts tb

V V V

V V V V

V V V

'

'

'

d d

s V s

b b

0LK

b ccs®


The elevator speech

The Wolfenstein parametrization The Unitarity condition (1 of 6)

The “b” Unitarity Triangle

The UT phases

CP-violating asymmetries in Bd, Bs decays can measure all the phases Combinations of tree level decay BRs can measure

Since any combination of three sides or angles determines a triangle, we can perform a unique set of overconstrained tests of the consistency of the CKM matrix

2 3

2 2 4

3 2

1 / 2 ( )

1 / 2 ( )

(1 ) 1CKM

A i

V A O

A i A

* * * 0ud ub cd cb td tbV V V V V V

: NB *

* *

*

*

* *

*

arg arg

arg arg

tb cd cb

ud tb

ud tb

td

ub td

ub tss

cd cb cs cb

V V VV

V VV V

V V

V V

V

V V

V

(if the elevator is in the physics department)


At the start of the “At the start of the “BB Factory era” Factory era”Dib, Dunietz, Gilman and Nir - 1989- 1989

The mass of the top quark, required to sharpen UT tests, was unknown



At the start of the “At the start of the “BB Factory era” Factory era”Dib, Dunietz, Gilman and Nir - 1989- 1989


Many measurements provide unitarity triangle constraints

Theoretical errorsare often pertinent


To measure the CP asymmetry in decays to CP eigenstates requires a time-dependent analysis

0 02

0 02 0

22 0

2Im ( ) ( )

1 | |( )( ) ( )

1 | | ( ) [ sin cos ]

1 | | ( )

CPCP CP

CPCP

CP CPiCP CP

CPCPCP CP

SB f B fA t

B f B fA B f

C eS m t C m tA B f


Reconstruct exclusive B decays to CP eigenstates and flavor eigenstates and tag the flavor of the other B decay

Measure z between BCP and Btag to determine thesigned time difference t between the decays

( )

0 0

flav

0 *

Select candidates

( / , .)

and candidates

, .

CP

S

B

B J K etc

B

B D etc

p- +

Select events using, primarily,

leptons and 's from hadronic

decays & determine flavor

tagB

K B

B

i

i

i

Measure the and determine thedilut

mistag fractions ions

= 1- 2 w

wD

Determine the resolution function for z

2 23

1ˆ( ; ) ( ) / 2

2expi

i i

i

i

i

fR t a t

Here’s how:

z

0tagB

e-

( )4SU

K

0recB

0SK

J / y

e+

z

0tagB

e-

( )4SU

K

0recB

0SK

J / y

e+


Global CKM Fit Consistency of angles

Consistency of angles and sides from global fitOverall good fit (CKMFitter:

global p-value 45%)~2σ tension between sin2β

and εK / Vub

correction to εK will make fit worse Buras, Guadagnoli, PRD78, 033005 (2008)

4.44.289.0

21.1 0.9

75 12

o

o

o

185 13o

0.0250.027

0.0160.015

UTFit: 0.154 0.022 CKMFitter: 0.139

0.342 0.014 0.341


b0Bd

s

V*td

dV*td

t

td

scc

0SK

/J b0Bd c

c

0SK

/J

sin2β from decaysb ccs

* *2

* *( 1) itb td cb cs

treetb td cb cs

V V V Vq Ae

p A V V V V


sin2β from decaysTheoretically clean measurement of |S| = sin2β with B J/ψ K0, J ψ ψ(2SScScSby BABAR and Belle

BABAR, PRD 79,072009 (2009)

0.672 0.0230.004 0.019

WA

WA

SC

0.687 0.028 0.0120.024 0.020 0.016

SC (21.1 0.9) statistically limited

b ccs




sin2from decays

V*td

b

d

u

d

uuVub

d

ub 0B

d d

d

0B

V*tdt

t

b uud

2 2 2

mixing decay

i i ie e e


Sππ sin2aeff = sin2( )

b → u “tree” b → d “penguin”d

Two amplitudes (P/T ~ 0.3) :

2 2 2

mixing decay

i i ie e e

Determine from isospin analysis Gronau & London, PRL 65, 3381 (1990)

PRL 98, 211801 (2007)

Excluded at 95% CL

,

,

0.65 0.070.38 0.06

WA

WA

SC

0.61 0.10 0.04 (5.3 )0.55 0.08 0.05 (5.5 )

SC

sin2 from B0


Grossman-Quinn

Gronau-London-Sinha2

Ouch !


sin2 from B , VV decay B Separate isospin analysis for each

polarization amplitude Longitudinal polarization >90% Small penguin contribution in B →

0 0 0,

0 6

0 6

0 0 0 6

(24.2 3.2) 10

(24.0 2.0) 10

(0.73 0.28) 10

Br B

Br B

r BB

PRL 102, 141802 (2009)

+4.44.2=89.0

0.05 0.17 0.06 0.13

SC


fromB D(*)K Decays Rates of B± D (*) K± decays are

sensitive to through interferenceof b c and b u transitionsNeed states accessible to and

Several neutral D (*) final states have been studied by BABAR, Belle and CDF

Must also determineD decays:GLW : CP eigenstates , KK, etc.)Gronau & London, PLB 253, 483 (1991);Gronau & Wyler, PLB 265, 172 (1991)

ADS: Flavor DCSD states (K)Atwood, Dunietz, & Soni, PRL 78, 3257 (1997),Atwood, Dunietz, & Soni, PRD 63, 036005 (2001)

GGSZ: 3-body decays (KSKSKK)Giri, Grossman, Soffer, & Zupan, PRD 68, 054018 (2003)Bondar, PRD 70, 072003 (2004)

New BABAR measurement with first evidence for ADS signal in B- → DK-

3.4 σ

Lopez-March @ EPS’09

( )0D ( )0D

0D

s

B

c

b

u

u

Vub

u

uc

B

b

usu

K

K

0D

Vcb

( )

( )b

A b ur

A b c


fromB- D(*)K- DecaysInterference in B- D (*)K- decays with 3-body Dalitz

analysis of D KSπ π, D KSKK are sensitive to


CKM Fitter resultsCKM Fitter resultsas of Moriond 2010as of Moriond 2010Adding in the CP asymmetrymeasurements from BABAR and

Belle,

we now have a set of highly overconstrained tests, which grosso modo, are well-satisfied 0.025

0.027

0.0160.015

UTFit: 0.154 0.022 CKMFitter: 0.139

0.342 0.014 0.341

4.44.289.0

21.1 0.9

75 12

o

o

o

185 13o

Are we th

ere yet?

Are we th

ere yet?


A decade of progress


sufficient constraints to explore subsets

All CP-conservingCP-violating

Tree amplitudes Loop amplitudesAngles only


Whither Heavy Flavor Physics ?Whither Heavy Flavor Physics ? Flavor physics provides the experimental foundation of much of the avor physics provides the experimental foundation of much of the

Standard ModelStandard Model Heavy flavor physics plays an important role, in that it furnishes many Heavy flavor physics plays an important role, in that it furnishes many

parameters that can beparameters that can be determined experimentally with precisiondetermined experimentally with precision compared with reliable theoretical predictionscompared with reliable theoretical predictions

As such, heavy flavor physics has served As such, heavy flavor physics has served to establish major pillars of the Standard Modelto establish major pillars of the Standard Model::

the particle contentthe particle content the weak couplingsthe weak couplings the suppression of flavor-changing neutral currents, ……the suppression of flavor-changing neutral currents, ……

and and to constrain what lies beyond the Standard Modelto constrain what lies beyond the Standard Model

When new physics is found at the LHCWhen new physics is found at the LHC Flavor physics has provided, and will continue to provide,Flavor physics has provided, and will continue to provide,

unique information on the nature of any new physics found at LHCunique information on the nature of any new physics found at LHC


Can we learn more ?Can we learn more ? Unitarity triangle tests

These primarily involve measurements in the B system, but require measurements of the Cabibbo angle, K and theoretical inputs

1.Does the agreement of the overconstrained tests stand up to detailed scrutiny ?

2.Can the UT tests be improved with better theoretical calculations and/or improved experiments ?

3. Is there any room for new physics ?

There are a few issues Overconstrained tests of three generation unitarity Does the unitarity triangle close ? Are there extra mixing phases ? Are there extra CP-violating phases ?



The The BB((BB→→)) conflictconflict

Also constrains Higgs doublet models

G. Eigen

2 2 2 22

2( ) 1

8F B B

ub

B

G f m m mB V

m


The The KK problem problem The four B→K decays provide four branching fraction measurements, four direct

CP asymmetries and one mixing-induced CP asymmetry (B0→K0 0) The decay amplitudes are related by isospin

The amplitudes can be written in terms of tree and penguin Standard Model amplitudes

A SM sum rule (Gronau-Rosner) relates the asymmetries

Consistent with the SM at the 20% level New Physics:

NP in PNPeip A(K0) = -0.15 NP in PC

EW,NPeiEW A(K0) = -0.03

G. Eigen0( ) ( )CPA A K A K

0 0 0 0 0 0( ) 2 ( ) 2 ( ) ( ) 0A B K A B K A B K A B K

0 0 0 00 0 0 0

0 0

( ) 2 ( ) 2 ( )( ) ( ) ( ) ( )

( ) ( ) ( )

K K KA K A K A K A K

K K K

B B BB B B

, ,

, ,,

1 2

3 3

C Cu dP

C C CEW u d

i ii C u C dNP

i i i CC C u C dEW NP

P e A e A e

P e A e A e


SM predicts very small βs (~0.02) Thus sensitive to new physics in Bs mixing

DØ and CDF measure βs with fit to decay time and angular distribution of Bs → J/ψ Simultaneous fit to extract ΔΓs and βs

βs from Bs → J/ψ decays

DØ and CDF working on updates with >2x samplesLHCb sensitivity with 0.5 fb-1: s


Does the agreement of the overconstrained tests stand up to detailed scrutiny ?

There is actually some tension, and there are enough constraints to explore these issues Caveats: There may be Standard Model

explanations for some effects All issues are at the <3 level

Inclusive and exclusive Vub determinations are not in good agreement There are also issues with inclusive/exclusive Vcb

The B(B→) conflict in Vub

The Bs → ψϕ phase The K problem The agreement of the fitted, i.e., SM-predicted, value of sin 2

vs the directly measured value using tree decays and loop decays is not perfect

Lunghi and Soni


Is there a fourth quark generation ?Is there a fourth quark generation ? A fourth generation CKM-like mixing matrix has

2 additional quark masses 3 additional mixing angles 2 additional CP-violating phases

A recent analysis by Bobrowski, Lenz, Reidl and Rohrwild (Phys.Rev.D79:113006,2009)shows that large regions of the new parameter spaces are still allowed

SuperB will be the primary tool to close down, or, perhaps find, non-zero values of these fourth generation parameters

Potential motivation (Hou): with 4 generations and mt', mb' ~300-600 GeV, gain 1013-1015 in the effect of SM CP violation on the baryon asymmetry of the universe !


Correlations in CP asymmetries in rare decays are diagnostic of SM4 models

SM4 models have been comprehensively explored by Buras, Duling, Feldmann, Heidsieck, Promberger & Recksiegel (arXiv:1002.2126v2 [hep-ph])

Many CKM extension patterns are possible in the mixing matrix For example, a 1, ,2,3,4 pattern for 0ff-diagonal terms leads to a “Wolfenstein”

parametrization:

Many other VSM4 patterns are possible. They can be identified, and distinguished from SUSY and extra dimension models, by the observed patterns of CP-violating effects:

=

There are also additional effects in KL, Bd and Bs decays


Okada, et al: a sample of new physics models


CPCPVV Probes of New Physics Probes of New Physics In the Standard Model we expect the same value for “sin2

” in modes, but different SUSY models can produce different asymmetries

Since the penguin modes have branching fractions one or two orders of magnitude less than tree modes, a great deal of luminosity is required to make these measurements to meaningful precision0 0/ SB J K

, , ,b ccs b ccd b sss b dds

* *2

* *( 1) itb td cb cs

treetb td cb cs

V V V Vq Ae

p A V V V V

* *2

* *( 1) itb td tb ts

penguintb td tb ts

V V V Vq Ae

p A V V V V

0 0SB K

~

b u,c,t s b u,c,t s b u,c,t s b d,s,b s

W - H - - g, 0

~~ ~~ ~~

SUSY(2 ) SUSYsin(2 )iK

Ae S

A


from b s(qq) penguin loop decays

In the SM the penguin decay amplitude is dominant and has same weak phase as bqqs amplitudeexpect to measure |S| = sin(2)SM contributions from suppressed

diagrams expected to be small (sin(2) = sin(2eff) sin(2) ~ 0.01-0.1)

Penguin decays with b → sqq loop sensitive to New Physics from heavy particles New Physics contributions could

cause large sin(2)

b s

g

t

0B

BABAR PRD 79, 052003 (2009)

0 0' SB K

0 0' SB K

0 0

0 0

N B N B

N B N B

467M BB

sin 2 0.57 ± 0.08 ± 0.020.08 ± 0.06 ± 0.02

eff

C


sin2β from b s(qq) penguin loop decays

CP asymmetries have been measured in 9 different b s (qq) modes by BABAR/Belle All measurements of sin2βeff are

consistent with sin2βb→ccs

C is consistent with zeroNaïve average sin2βeff of all b → sqq

modes used to be ~3σ lower than sin2β (~2004), now ~1σ

Some modes (') have relatively small theoretical uncertainties (~5%)

,sin2 0.59 0.06eff clean

Theoretically clean modes


1) 2) There are important penguin and tree corrections

2~tb tsV V

b

d

g

t

d

ss

s

W

0', f

0K

b

d

g

t

d

ds

d

W

2~tb tsV V

0 0, ,

0K

4~ iub us uV V R e

W b

d

d

uu

0', f

s 0K

4~ iub us uV V R e

W b

d

d

uu 0 0, ,

s 0K

0K

b

d

g

t

d

ss

s

W

2~tb tsV V

b

dg

u

d

ss

W

4~ iub us uV V R e

0Ks

Correctionsof up to 20%correctionsfor sin2β are possible

Thesecorrectionscan becalculatedand/orbounded

Gold

Silv

er

Bro

nz

e

4

29

20

0/ 440SJ Ky x10-6

b sss b ccs decays have 1-5% the rate of decays


Can we resolve these outstanding issues in heavy flavor physics? To access the very rare b, c and decays that can show effects

due to a fourth generation, SUSY, extra dimensions, etc., requires large hadronic data samples (viz. LHC) and an e+e- data sample ~100x as large as the total BABAR/Belle data set (~1.3 ab-1)

As none of us is getting any younger, obtaining this sample in our lifetime requires an asymmetric collider with a luminosity of 1036,which can record 15 ab-1/New Snowmass Year, as well as a detector that can cope with the event rates and backgrounds

BABAR

SuperB


Lepton Flavor Violation in decaysSuper Super BB Factory sensitivity directly confronts New Physics models Factory sensitivity directly confronts New Physics models

SuperBsensitivityFor 75 ab-1

We expect to see LFV events, not just improve limits


A longitudinally polarized electron beam, producing polarized ’s,can determinate the chiral structure of lepton flavor-violating interactions

Polarized Polarized ’’s can probe the chiral structure of LFVs can probe the chiral structure of LFV in a model-independent manner in a model-independent manner

Dassinger, Feldmann, Mannel, and TurczykJHEP 0710:039,2007;

[See also Matsuzaki and SandaPhys.Rev.D77:073003,2008 ]

Also: •Reduction in backgrounds for rare decays•Measurement of anamolous magnetic moment•Search for CP or T violation in production and decay


A longitudinally polarized electron beam, producing polarized ’s,can determinate the chiral structure of lepton flavor-violating interactions

Polarized Polarized ’’s can probe the chiral structure of LFVs can probe the chiral structure of LFV in a model-independent manner in a model-independent manner

Dassinger, Feldmann, Mannel, and TurczykJHEP 0710:039,2007;

[See also Matsuzaki and SandaPhys.Rev.D77:073003,2008 ]

Also: •Reduction in backgrounds for rare decays•Measurement of anamolous magnetic moment•Search for CP or T violation in production and decay


A DNA Chip for New Physics

Altmannshofer, Buras,Gori, Paradis and StraubNucl.Phys.B830,7-94, 2010


The National Research Planfor 2010-2012 of the Italian Ministry of Education and Science


ConclusionsConclusions CP violation experiments have provided some of the key

building blocks for the construction of the three generation Standard Model

Through a series of overconstrained tests the B factories have convincingly shown that the CKM phase can account for a wide variety of experimental phenomena, although there are still some intriguing discrepancies

This, of course, leaves us with the mystery of the origin of the matter-antimatter asymmetry (leptogenesis ?)

There is still room for a fourth generation, which could be pertinent to the baryon symmetry problem

SM extensions provide many additional CP-violating phases

Super B Factories, now hopefully near to becoming a reality, can provide unique sensitivity to explore this area, and, more generally, the flavor structure of any new physics found at the LHC

Documents

David Hitlin Quinn Symposium April 16, 2010 1 Experiments on CP Violation in B Meson decay David Hitlin Matter and Antimatter: Fact and Fancy April 16,