Testing the SM with penguin-dominated B-decays

27
Testing the SM with penguin-dominated B- decays Amarjit Soni HET,BNL ([email protected])

description

Testing the SM with penguin-dominated B-decays. Amarjit Soni HET,BNL ([email protected]). Outline. How good a null test is this? How well does the penguin-dominate? Possible dynamical enhancement of u-quark ? Why (LD)FSI has become a significant concern? How can we tackle this complication? - PowerPoint PPT Presentation

Transcript of Testing the SM with penguin-dominated B-decays

Page 1: Testing the SM with penguin-dominated B-decays

Testing the SM with penguin-dominated B-decays

Amarjit Soni

HET,BNL

([email protected])

Page 2: Testing the SM with penguin-dominated B-decays

Outline• How good a null test is this? • How well does the penguin-dominate?• Possible dynamical enhancement of u-quark ?• Why (LD)FSI has become a significant concern?• How can we tackle this complication?• How well can we exploit correlation between

ΔSf (=Sf – SψK ) and Cf ?• Can we make stronger statement about the sign of ΔSf ?

• Are there (theoretically) problematic modes?• Averaging issue• Summary and Conclusions

.

Page 3: Testing the SM with penguin-dominated B-decays

Questions for the Super-B Workshop

Page 4: Testing the SM with penguin-dominated B-decays

Brief Recapitulation: Basic Idea

Dominant decay amp.has0 weak phase [just as in

B->ψKS] up to O(λ2)

Page 5: Testing the SM with penguin-dominated B-decays

Brief remarks on the old study(with London, PLB’97)

• Originally motivated by the thenCLEO discovery of• Huge inclusive (see Browder..) as well as exclusive• (see J. Smith…) Brs. into η’ • Suggest with Atwood(PLB97;PRL97) use of η’ Xs(d)

• for search of NP via DIRCP as in SM expect very small• With London suggest use of MICP in [η’ ,

η ,π0,ρ0,ω,φ….]KS to test CKM-paradigm via sin2φ1(β)• Present simple (naïve) estimates of T/P …for• All cases T/P <0.04• Due to obvious limitations of method suggest conservative• Bound ΔSf <0.10 for the SM

For DIRCP see also Hou&Tseng,PRL’98

Page 6: Testing the SM with penguin-dominated B-decays

J. Smith@CKM05

WA ~ 2.7σ

Page 7: Testing the SM with penguin-dominated B-decays

Physics Summary SBF'05 HawaiiJ.Smith@CKM05

Page 8: Testing the SM with penguin-dominated B-decays

Averaging issue:Are we makinga mountain outa anthill?

• I am rather sceptical and concerned about

averaging over many small deviations,

leading to ~3.7 σ ….On the other hand,

London&A.S,hep-ph/9704277

Page 9: Testing the SM with penguin-dominated B-decays

Null Test(s)• In light of B-factory results (existing exptal

info+lattice+phenomenology)-> deviations from CKM-paradigm due BSM-CP-odd phase(s) are likely to be small-> should develop Null Tests

• Since CP is not an exact symmetry of SM->No EXACT NULL TESTS-> Need “Approximate Null Tests” (ANTs).

• In b->s transitions, penguin-dominated B-decays are a powerful ANT• W(“worthiness”)=C(“cleanliness”) X S(“sensitivity”)=4.5* X 5*• ANT: In large class of modes such as (π0,ρ,ω,η’,φ,f0,K0K0…)K0 ,

(penguin/Total) ~ 1 -> ΔSf ~0• Summary of early (London + AS, PLB’97) study….• ΔSf < 0.1 in the SM (for modes discussed therein)• Summary of Recent Reaxmination (Cheng,Chua+AS,hepph/0502235….) ,

ΔSf > 0.1 most likely due BSM-CP-odd phase (for many modes)

Page 10: Testing the SM with penguin-dominated B-decays

Browder&A.S,hep-ph/04 10192

Page 11: Testing the SM with penguin-dominated B-decays

A possible complications: large FSI phases in 2-body B decays

• The original papers predicting ΔSf=Sf - SψK ~0 used naïve factorization ideas; in particular FSI were completely ignored.A remarkable discovery of the past year is that directCP in charmless 2-body modes is very large->(LD)FS phases in B-decays need not be smallSINCE THESE ARE INHERENTLYNon-perturbative model dependence becomesunavoidable

Page 12: Testing the SM with penguin-dominated B-decays

3

F S I i n c h a r m l e s s B d e c a y s F S I i n c h a r m l e s s B d e c a y s

723 10.3 6.5 2437

7.1 9.12 0.6 48

517 4.1 4.5 211

2.131.00.31.28.123.08.21.2

0

1.02.0

5.111.03.12.07.111.06.11.0

1415

0

7.85.02.21.15.96.05.21.1

0

B

B

KB

E x p t ( % ) Q C D F ( B N ) Q C D F ( S 4 ) p Q C D

1 . D i r e c t C P v i o l a t i o n

p Q C D ( K e u m , L i , S a n d a ) : A s i z a b l e s t r o n g p h a s e f r o m p e n g u i n -i n d u c e d a n n i h i l a t i o n b y i n t r o d u c i n g p a r t o n ’ s t r a n s v e r s e m o m e n t u m

Q C D F ( S 4 ) s c e n a r i o : l a r g e a n n i h i l a t i o n w i t h p h a s e c h o s e n s o t h a t a c o r r e c t s i g n o f A ( K + - ) i s p r o d u c e d ( A = 1 , A = - 5 5 f o r P P )

I t i s c o n c e i v a b l e t h a t L D s t r o n g p h a s e s i n d u c e d f r o m F S I sw i l l h a v e a s t r o n g i m p a c t o n D C P V p h e n o m e n o l o g y

D C P V s i n s i n ( : w e a k p h a s e , : s t r o n g p h a s e )

HYC-CKM05

Page 13: Testing the SM with penguin-dominated B-decays

4

2. Some color-suppressed or factorization-forbidden or penguin-dominated modes cannot be accommodated in the naïve factorization approach

Some decay modes do not receive factorizable contributions

e.g. B K0c with sizable BR though 0c|c(1-5)c|0=0.

Color-suppressed modes e.g. B0 D0 h0 (h0=0,,0,,’), 00, 00

have the measured rates larger than theoretical expectations.

Penguin-dominated modes such as B K*, K, K, K* predicted by QCDF are consistently lower than experiment by a factor of 2 3

importance of power corrections (inverse powers of mb)e.g. FSI, annihilation, EW penguin, New Physics, …

HYC-CKM05

Page 14: Testing the SM with penguin-dominated B-decays

5

Regge approach [Donoghue,Golowich,Petrov,Soares]

FSI phase is dominated by inelastic scattering and doesn’t vanish even

in mb limit

QCDF [Beneke,Buchalla,Neubert,Sachrajda]

strong phase is O(s, /mb): systematic cancellation of FSIs in mb

Charming penguin [Ciuchini et al.] [Colangelo et al.] [Isola et al.]

long distance in nature, sources of strong phases, supported by SCET

One-particle-exchange model for LD rescatteringhas been applied to charm and B decays [Lu,Zou,..], [Du et al.]

Quasi elastic scattering model [Chua,Hou,Yang]

Consider MM MM (M: octet meson) rescattering in B PP decays

Diagrammatic approach [Chiang et al.] …

Approaches for FSIs in charmless B decays

HYC-CKM05

Page 15: Testing the SM with penguin-dominated B-decays

7

F S I a s r e s c a t t e r i n g o f i n t e r m e d i a t e t w o - b o d y s t a t e s

[ H Y C , C h u a , S o n i ]

F S I s v i a r e s o n a n c e s a r e a s s u m e d t o b e s u p p r e s s e d i n B d e c a y s d u e t o t h e l a c k o f r e s o n a n c e s a t e n e r g i e s c l o s e t o B m a s s .

F S I i s a s s u m e d t o b e d o m i n a t e d b y r e s c a t t e r i n g o f t w o - b o d y i n t e r m e d i a t e s t a t e s w i t h o n e p a r t i c l e e x c h a n g e i n t - c h a n n e l . I t s a b s o r p t i v e p a r t i s c o m p u t e d v i a o p t i c a l t h e o r e m :

i

ifTiBMfBMm )()( 2

• S t r o n g c o u p l i n g i s f i x e d o n s h e l l . F o r i n t e r m e d i a t e h e a v y m e s o n s ,

a p p l y H Q E T + C h P T ( f o r s o f t G o l d s t o n e b o s o n )

• F o r m f a c t o r o r c u t o f f m u s t b e i n t r o d u c e d a s e x c h a n g e d p a r t i c l e i s

o f f - s h e l l a n d f i n a l s t a t e s a r e h a r d

A l t e r n a t i v e : R e g g e t r a j e c t o r y [ N a r d u l l i , P h a m ] [ F a l k e t a l . ] [ D u e t a l . ] …

Page 16: Testing the SM with penguin-dominated B-decays

8

D i s p e r s i v e p a r t i s o b t a i n e d f r o m t h e a b s o r p t i v e a m p l i t u d e v i a d i s p e r s i o n r e l a t i o n

''

)'( )(

0

22 ds

ms

sMmPmMe

s BB

= m e x c + r Q C D ( r : o f o r d e r u n i t y )

o r r i s d e t e r m i n e d f o r m a 2 f i t t o t h e m e a s u r e d r a t e s

r i s p r o c e s s d e p e n d e n t

n = 1 ( m o n o p o l e b e h a v i o r ) , c o n s i s t e n t w i t h Q C D s u m r u l e s

O n c e c u t o f f i s f i x e d C P V c a n b e p r e d i c t e d

s u b j e c t t o l a r g e u n c e r t a i n t i e s a n d w i l l b e i g n o r e d i n t h e p r e s e n t w o r k

F o r m f a c t o r i s i n t r o d u c e d t o r e n d e r p e r t u r b a t i v e c a l c u l a t i o n m e a n i n g f u l

n

QCD

n

t

m

t

mtF

2

22

)(

L D a m p . v a n i s h e s i n H Q l i m i t

Page 17: Testing the SM with penguin-dominated B-decays

All rescattering diagrams contribute to penguin topology,

dominated by charm intermediate states

fit to rates rD = rD* 0.67

predict direct CPV

B B

Should reduce model dependence Significantly for CPV

Page 18: Testing the SM with penguin-dominated B-decays

1 8

T h e o r e t i c a l u n c e r t a i n t i e s

1 . M o d e l a s s u m p t i o n

- - m u l t i - b o d y c o n t r i b u t i o n s

- - f o r m - f a c t o r c u t o f f :

i ) . n = 1

i i ) . = m e x c + r Q C D (1 5 % e r r o r a s s ig n e d fo r Q C D )

r D = 2 .1 , 1 .6 , 0 .7 3 , 0 .6 7 , r e s p e c tiv e ly , fo r D , , K m o d e s

0 .9 5 fo r p e n g u in -d o m in a te d P V m o d e s

- - d i s p e r s i v e c o n t r i b u t i o n

2 . I n p u t p a r a m e t e r s

- - s t r o n g c o u p l i n g s o f h e a v y m e s o n s a n d t h e i r S U ( 3 ) b r e a k i n g

- - f o r m f a c t o r s & d e c a y c o n s t a n t s

- - s t r a n g e q u a r k m a s s

n

t

mtF

2

22

)(

Page 19: Testing the SM with penguin-dominated B-decays

22

FSI effect is tiny due to small source (K*,K) amplitudes (Br~10-6) compared to Ds*D (Br~10-2,-3). It tends to alleviate the deviation from sin2

DCPV is predicted to be of order 15% in KS, 50% in 0KS and a few percents in all other modes.

---0.50+0.06-0.02-0.11--0.722+0.066

-0.0720.6240KS

?

0.7740.008

0.7320.001

0.7360.016

0.7550.006

SD+LD

?

-0.0240.009

-0.0210.0

0.1510.018

0.025+0.002-0.005

SD+LD

0.140.22-0.0080.390.260.747f0KS

0.090.140.0430.340.280.7820KS

-0.040.08-0.0180.410.110.735‘KS

-0.490.250.0760.560.320.850KS

-0.040.17-0.0170.340.200.745KS

ExptSDExptSD

Cf-nfSf

HYC-CKM05

Page 20: Testing the SM with penguin-dominated B-decays

Cheng,Chua,A.S.Hep-ph/0502235

1.Note in SD, ΔS switches sign bet. ω,ρ for us no change2. LD rescattering effects on S & C are highly correlated and similarlyC’s of isospin partners are correlated -> many testable predictions,e.g

LARGE (13%)DIR CP for ω KS & HUGE for ρ KS (~ -46%)

Page 21: Testing the SM with penguin-dominated B-decays

Correlation between MixingInduced and Direct CP

Page 22: Testing the SM with penguin-dominated B-decays

BR

SD

(10-6)

BR

with FSI

(10-6)

BR

Expt

(10-6)

DCPV

SD

DCPV

with FSI

DCPV

Expt

B 16.6 22.9+4.9-3.1 24.11.3 0.01 0.026+0.00

-0.002 -0.020.03

B0 13.7 19.7+4.6-2.9 18.20.8 0.03 -0.15+0.03

-0.01 -0.110.02

B0 9.3 12.1+2.4-1.5 12.10.8 0.17 -0.09+0.06

-0.04 0.040.04

B0 6.0 9.0+2.3-1.5

11.51.0 -0.04 0.022+0.008-0.012 -0.090.14

Only LD uncertainties due to form-factor cutoff are shown here.

Total errors=SD+LD, for example,

FSI yields correct sign and magnitude for A(+K-)

P/T|SD=0.12 exp(-i177), P/TSD+LD=(0.140.01)exp[i(1478)]

_

_

_

_

)(7.19)(7.13)(10 6.45.109.23.5

6.105.5

06 LDSDSDKBBr

Page 23: Testing the SM with penguin-dominated B-decays

17

--0.50+0.06-0.020.105.11.65.0+1.3

-0.82.9B0

---0.40+0.02-0.08-0.0135.15+0.91

-0.893.9+1.5-0.91.2B 0

0.17+0.15-0.16-0.18+0.04

-0.060.0329.9+1.6-1.511.1+2.9

-1.94.2B0 +

---0.008+0.001-0.0020.004 <489.8+3.0

-1.93.1B

DCPV

Expt

DCPV

with FSI

DCPV

SD

BR

Expt

(10-6)

BR

with FSI

(10-6)

BR

SD

(10-6)

B B

_

_

PV/TV|SD=0.040 exp(-i3 ),

PV/TV|SD+LD=(0.079+0.012

-0.009) exp[i(2710) ]

|P/T|SD is smaller than K* case due to opposite sign between a4 and a6

_

_

Note the very large (~ -40%) DCP in ρ0 K- & ρ0 K0

Page 24: Testing the SM with penguin-dominated B-decays

More remarks

& ρ0KS May be a goodway

Based on our study it seems difficult to accommodateΔS>0.10 within the SM at least for KS[ή,φ]

Page 25: Testing the SM with penguin-dominated B-decays

Summary (1 of 2)1) Penguin dominated B-decays (b->s) are very useful “ANTs” of SM;

for many modes ΔS>0.10 difficult to accommodate in SM.

2) The η’ KS is esp. clean…due dominance of Penguin (huge Br), which

was in fact the original motivation for suggesting the η’ ; Model calculations show ΔS(η’ KS )~0.01. Since expt. Error for η’ KS

is smallest (0.11), prospects for precision for this mode seem promising.

3) S-C correlation provides a very useful check On the models -> improved expt. measurements should lead to improvements in the models -> other modes may also become useful.

4) Noteable predictions of our model: large dir.CP in [ π,ρ] K- , [ρ,ω]KS

5) The sign of ΔS in our (and several other) model(s) tends to be positive

with small central value (compared to largish ) errors; thus conclusive

statements regarding the sign are difficult to make (Exptal. sign of ΔS

tends to be negative!)

Page 26: Testing the SM with penguin-dominated B-decays

Sign of ΔS in the SMMode pQCD(SM ) QCDF(MB) QCDF+FSI(CCS)

η’KS .01(.01,-.01) .00(.00,-.04)

φKS ..020(.004,-.008) .02(.01,-.01) .03(.01,-.04)

πKS .009(.001,-.003) .07(.05,-.04) .04(.02,-.03)

Page 27: Testing the SM with penguin-dominated B-decays

Summary (2):Bottomline

Most of the effect currently is driven by

the largish ΔS for η’ KS . If New Physics is responsible for this then NP MUST show up in numerous (b ->s) channels e.g. η’ K- , φ[K0,K-…](*), affecting mixing,

dir and triple-corr CP…AND BS physics. Also, in all liklihood, radiative , leptonic (b->s) should also be effected making Expts. With higher luminosities extremely rich and exciting!