Large electroweak penguin Large electroweak penguin contribution in B decayscontribution in B decays

T. Yoshikawa ( Nagoya )

基研研究会「ＣＰの破れと物質生成」　　２００５年　１月１２日～１４日

This talk is based on S. Mishima and T.Y. Phys.Rev. D70, 0940This talk is based on S. Mishima and T.Y. Phys.Rev. D70, 094024 (2004)24 (2004)

and T.Y. Phys.Rev. D68, 054023 (2003) .and T.Y. Phys.Rev. D68, 054023 (2003) .

CP Violation and BaryogenesisCP Violation and Baryogenesis

Slightly Slightly difficultdifficult to explain to explain within the SM.within the SM.　　　　　　 KM CP Phase is too small KM CP Phase is too small

Need the first order phase Need the first order phase transitiontransition

New Physics ?New Physics ? 　　 　　 new CP phasenew CP phase ? ?

Have the evidences already appeared Have the evidences already appeared in B decays?in B decays?

If new physics with extra CP phase If new physics with extra CP phase is existing,is existing,

B factories should (or will ) find the evidences in B factories should (or will ) find the evidences in B decays.B decays.

B factory(s) with super high luminosity may discover the new physics !!

before LHC, ILC .

To extract the information from To extract the information from B physics is quite important B physics is quite important subject.subject.

Present situation of unitarity triangle

No discrepancy between CKM fitting and direct measurement of CP phase .

3

sin21 Vtb*Vtd

Vcb*VcdVub*Vud

Vcb*Vcd

1

Several discrepancies seem Several discrepancies seem to appear in recent to appear in recent experimental data. experimental data.

Discrepancies between TH Discrepancies between TH and EXand EX

K - Puzzle

The direct CPVs are almost zero !! BUT the indirect CPV Ss are

How about the differences among these b-s penguin modes ?

Relations among the Relations among the branching ratiosbranching ratios Relation among Direct CP Relation among Direct CP asymmetriesasymmetries Large BLarge B Branching ratio Branching ratio 00

CP asymmetries : B K0 (b-s penguin type modes ) vs B J/ K0

Fleischer-Mannel, Neubert-Rosner, Lipkin, Buras, … T.Y., Gronau - Rosner, Buras-Fleischer et al , Li, ……. Many works.

sin21 =

……

……

sin2sin211 from from bbss penguins at ICHEP04 penguins at ICHEP04vsvs

from gold plated mode B from gold plated mode BJJss

sin21(bsqq) = 0.43 0.08 sin21(bccs) = 0.726 0.037

(3.6)

106

Belle

BABAR

_sin21 from ccs“s

in2

1”

History of “sin2History of “sin211” with ” with KK00

Hazumi

Question: If it is true, Question: If it is true, Where does the discrepancy Where does the discrepancy come from? come from?

Direct CP asymmetry : AJ/~ AK ~ ’

But

Sin21 = SJ/ == SK ~S’S

Is the origin in Penguin or EW Is the origin in Penguin or EW penguin ?penguin ?

or in color-suppressed tree ? or in color-suppressed tree ?

= 0= 0

Can we take the average among all Can we take the average among all modes ??modes ??

A(BK) = P + S –PEW /3

A(B’K) = ( 3 P + 4 S 　　 – PEW /3 　　 + C ) 　 /√ ６

A(BK) = ( P 　　 – PEW 　　 C )/√ ３

Which diagram should include the Which diagram should include the

discrepancy ?discrepancy ?

Is there any discrepancies in the other CP asyIs there any discrepancies in the other CP asy

m.?m.?

How large is it ?How large is it ?

Where is the origin of the new CP Where is the origin of the new CP

phase ?phase ?

Direct CP Violation :

theoretically 、　 1 > 　 r_T ~ r_{EW} > r_C > r_A

New Physics ? In rNew Physics ? In rEW EW EW penguin ? EW penguin ?

expectexpect BUT BUT differentdifferent !!!!

B decaysB decays

ＴＴｒｒｅｅｅｅ

QCDQCD ＰＰｅｎｅｎｇｕｉｎｇｕｉｎ

CColor olor suppressed suppressed

treetree

EElectrolectroWWeakeak

PPenguin (enguin (PPEWEW))

AAnnihilatinnihilationon SSinglet QCD inglet QCD

PenguinPenguin

CColor suppressed olor suppressed

EWEW PPenguinenguin

((PPCCEWEW ))

Gronau, Hernandez,London, Rosner

b

B decaysB decays

ＴＴｒｒｅｅｅｅ

QCDQCD ＰＰｅｎｇｅｎｇｕｉｎｕｉｎ

CColor olor suppressed suppressed

treetree

EElectrolectroWWeakeak

PPenguin (enguin (PPEWEW))

AAnihilationnihilationCColor suppressed olor suppressed

EWEW PPenguinenguin

((PPCCEWEW ))

Main Contributions Main Contributions T , P T , P

usually

Negligible Negligible ContributionsContributions PPCC

EW EW , , AA

How should we treat How should we treat PPEWEW, C ?, C ?

Discrepancies between TH Discrepancies between TH and EXand EX

K - Puzzle

The direct CPVs are almost zero !! BUT the indirect CPV Ss are

How about the differences among these b-s penguin modes ?

Relations among the Relations among the branching ratiosbranching ratios Relation among Direct CP Relation among Direct CP asymmetriesasymmetries

Large BLarge B Branching ratio Branching ratio 00

CP asymmetries : B K0 (b-s penguin type modes ) vs B J/ K0

We discuss what happens in B and decays .

Fleischer-Mannel, Neubert-Rosner, Lipkin, Buras, … T.Y., Gronau - Rosner, Buras-Fleischer et al , Li, ……. Many works.

sin21 =

KK - -

PuzzlePuzzle KK - -

PuzzlePuzzle Experimental data do not satisfy several relations among the branching ratios.

Before ICHEP04

Theory

Experiment

There were quite large discrepancies.There were quite large discrepancies.

Before ICHEP04

After After ICHEP0ICHEP044

What What changed ?changed ?

KK - -

PuzzlePuzzle KK - -

PuzzlePuzzle 1) Experimental data do not satisfy several relations among the branching ratios.

After ICHEP04

Still remaining the Still remaining the discrepancies !!discrepancies !!

KK - -

PuzzlePuzzle KK - -

PuzzlePuzzle 2) There seems to be a discrepancy in direct CP asymmetries of Bdirect CP asymmetries of B K K ..

After ICHEP04

Theoretically,

Experimental data,

Is the relation among the Acp s violated ?

We have to know what makes the We have to know what makes the discrepancies! discrepancies!

Do we still need large EW Penguin Do we still need large EW Penguin contribution ?contribution ?

Diagram Decomposition of B Diagram Decomposition of B K Kand and

Hierarchy in B Hierarchy in B K K

ＴＴｒｒｅｅｅｅ

QCDQCD ＰＰｅｎｇｅｎｇｕｉｎｕｉｎ

CColor olor suppressed suppressed

treetree

EWEW PPenguin enguin ((PPEWEW))

AAnnihilatinnihilation on ((EExchangexchange))

CColor suppressed olor suppressed

EWEW PPenguinenguin

((PPCCEWEW ))

Gronau, Hernandez,London, Rosner

b

Large

Small

They are rewritten as follows:

where r is the ratio of each diagram with QCD Penguin, and X is the strong phase difference.

where r is the ratio of each diagram with Tree contribution, and X is the strong phase difference. A (Exchange) and PC

EW are neglected here.

Hierarchy Hierarchy AssumptionAssumption

ＰＱＣＤ

in B in B K K

O(0.1)

O(0.01)

Hierarchy Hierarchy AssumptionAssumption

in B in B

O(0.1)

negligible

Branching ratios under the Branching ratios under the assumptionassumption

by neglecting r2 terms including rC, rcEW , rA (smaller terms than O(0.01 ). )

Fleischer-Mannel bound Fleischer-Mannel bound

We can find several relations We can find several relations among them. among them.

Some relations among the Some relations among the branching ratiosbranching ratios

These relation seems to be proportional to r2 so that they should be O(0.01) quantities .

=0 or not ?

Branching Branching ratios ratios Branching Branching ratios ratios

Rough estimation under assumption Rough estimation under assumption

~ 1 ? ~ 1 ?

Experimental dataExperimental data

> 0.1 > 0.1

1.04

+ + = 2 = 2

- = - = 00

=

=

=

Do we need large EW penguin Do we need large EW penguin contribution ? contribution ?

Relations

1

1

0.14

From the 1 From the 1 bound of Rbound of Rcc-R-Rnn, S, R, S, R++ -2 with -2 with rrTT = =0.2 0.2

We may still need slightly large EW penguin contribution. To discuss more detail, we need the information about strong phases.

If flavor SU(3) sym. is good, EW

and will be constrained by ACP .

Consider about direct CP asymmetries !! Consider about direct CP asymmetries !!

What can we expect

No strong phase difference between tree and EW(Z) penguin

bbWWzz

us

K

K BB

1)

2)

3)

under SU(3) symmetry. Because the diagrams are topologically same.

tree

EW Penguin

Neubert-Rosner,

Buras and Fleischer

Direct CP asymmetries in B in B K K

Relation among the CPRelation among the CP asymmetriesasymmetries :

Large EW Penguin ? Or Still early Large EW Penguin ? Or Still early ? ?

Cos T > 0 is favored. T should be around 20o.

Fleischer-Mannel bound

-0.114 0.020

as a function of T with rT = 0.2 .

CPA T should be around 20o or 1

50o

T

++

Maximum bound of Rc-Rn under constraints from ACP and R with rT = 0.2 .

We still need large EW penguin contribution and large strong phase difference.

is disfavored.

Relaxing the hierarchy assumptionRelaxing the hierarchy assumption = keeping = keeping rr22CC terms terms in

The lower bound of rC to satisfy Rc-Rn, S, R+ -2 at 1bound.

s are free parameters

2) EWcase

If large is allowed, it may explain the discrepancies. Chiang-Gronau-Rosner-Suprum

But it seems to be too largetoo large though it is color suppressed tree-type contribution.

The usual estimation is 0.02 .

Charn-Li

New Physics solutionNew Physics solution

One solution to solve such large strong phase difference is

to introduce a new CP phase as the new physics to introduce a new CP phase as the new physics contribution.contribution. New

Phase

New Phase

Even if QCD penguin does not include any new physics,

they can be controlled by EW contribution with new CP phase.

Even if QCD penguin does not include any new physics,

they can be controlled by EW contribution with new CP phase.

Rc - Rn and S within the New Physics with new Phase

For , there is the arrowed region for EW

ConclusionConclusion The allowed region of The allowed region of rrEWEW should be larger than about 0.2 should be larger than about 0.2 . . Still remaining the discrepancies !Still remaining the discrepancies ! Large strong phase differences are needed. Large strong phase differences are needed. SU(3) breaking ?SU(3) breaking ? As a possibility, we need to consider Large As a possibility, we need to consider Large rrc case also. c case also. Direct CP asymmetries will be more important to understanDirect CP asymmetries will be more important to understan

d d which is the origin of the discrepancies. which is the origin of the discrepancies. To keep , need new CP phase in To keep , need new CP phase in

Penguin type diagrams. Penguin type diagrams. Or LargeOr Large r rcc case. case.

If PEW is including New CP Phase, the effect must appear in CP asymmetries, Acp00 and SK

0

How about B ?

where .

It seems to be difficult to explain by only It seems to be difficult to explain by only EW penguin EW penguin

because it will be sub-leading because it will be sub-leading contribution.contribution.

To explain the large ratios, we need

1) To suppress the denominator . with

2) Larger rP

<<

00 00

Large may be possible if there is SU(3) breaking effect between b-s P and b-d Penguins . BUT the magnitude will be constrainted from B KK (pure b-d penguin ) modes.

d

s

sK

K

Pure b-s penguin

Pure b-d penguin

At largest, At largest, PP is 1.5 times is 1.5 times larger. larger. We can not take so large .

How about B ?

where .

It seems to be difficult to explain by only It seems to be difficult to explain by only EW penguin EW penguin

because it will be sub-leading because it will be sub-leading contribution.contribution.

To explain the large ratios, we need

1) To suppress the denominator . with 2) Larger rP

3) Larger (color suppressed tree )

Or New Physics ??New Physics ?? with new CP phase

Before considering about New Physics, review the contribution from Before considering about New Physics, review the contribution from rrCC . .

An example: EWC =

or

+

+

Large

SU(3) breaking

Possibility of New Physics ?

or