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Flavor , Charm , CP Related Physics. Hai-Yang Cheng Academia Sinica, Taipei. PASCOS, Taipei November 22, 2013. Outline: Quark and lepton mixing matrices Baryonic B decays Direct CP violation in D decays

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Flavor, Charm, CP Related Physics

Hai-Yang Cheng

Academia Sinica, Taipei

PASCOS, Taipei

November 22, 2013


Outline:

  • Quark and lepton mixing matrices

  • Baryonic B decays

  • Direct CP violation in D decays

  • Direct CP violation in B decays

See the talk of Rodrigues (11/21)



CP Violation in Standard Model

VCKM is the only source of CPV in flavor-changing process in the SM. Only charged current interactions can change flavor

Kobayashi & Maskawa (’72) pointed out that one needs at least six quarks in order to accommodate CPV in SM with one Higgs doublet

1>>1>>2 >>3

Physics is independent of a particular parameterization of CKM matrix, but VKM has some disadvantages :

  • Determination of 2 & 3 is not very accurate

  • Some elements have comparable real & imaginary parts

4


Maiani (’77)

advocated by PDG (’86) as a standard parametrization.

However, the coefficient of the imaginary part of Vcb and Vts is O(10-2) rather than O(10-3) as s23  10-2

In 1984 Ling-Lie Chau and Wai-Yee Keung proposed a new parametrization

1>>12>>23 >>13

s13 ~ 10-3

The same as VMaiani except for the phases of t & b quarks. The imaginary part is O(10-3). This new CKM(Chau-Keung-Maiani) matrix is adapted by PDG as a standard parametrization since 1988.


Some simplified parametrizations

  • Wolfenstein (’83) used Vcb=0.04  A2,   0.22

Mixing matrix is expressed in terms of , A ~ 0.8,  and . Imaginary part = A3 10-3. However, this matrix is valid only up to 3

  • Motivated by the boomerang approach of Frampton & He (’10), Qin

    & Ma have proposed a different parametrization (’10)

Wolfenstein parameters A, ,  QM parameters f, h, 

6


The original Wolfenstein parametrization is not adequate for the study of CP violation in charm decays, for example. Hence it should be expanded to higher order of 

Wolfenstein parametrization up to 6

Wolfenstein parametrization can also be obtained from KM matrix by making rotations: s s ei, c c ei, b b ei(+), t t e-i(-) and replacing A, , ,  by A’, ’ , ’ and ’


Look quite differently from those of the study of CP violation in charm decays, for example. Hence it should be expanded to higher order of V(CK)Wolf

8

8


Buras et al. (’94): As in any perturbative expansion, high order terms in  are not unique in the Wolfenstein parametrization, though the nonuniquess of the high order terms does not change physics

Wolfenstein (’83) used |Vub| ~ 0.2 |Vcb| ~ A3

Now |Vub| ~ 0.00351, |Vcb| ~ 0.0412  |Vub| ~ 2 |Vcb|~ A4

  • ~ 0.129,  ~ 0.348 not order of unity !

    We define & of order unity

9


Most of the discrepancies are resolved via the definition of the parameters , of order unity

  • Remaining discrepancies can be alleviated through

  • Vus =  = ’

  • from Vcb

  • from Vub

Ahn, HYC, Oh

arXiv:1106.0935

10


Lepton mixing matrix the parameters

Pontecorvo, Maki,

Nakagawa, Sakata

12 = solar  mixing angle, 23 = atmospheric  mixing angle,

13 = reactor  mixing angle

A different parametrization has been studied:

Huang et al.

1108.3906; 1111.3175

12 ~ 19o, 23 ~ 46o, 13 ~ 29o are quite different from

12 ~ 34o, 23 ~ 38o, 13 ~ 9o


the parameters 12 ~ 13o, 23 ~ 2.4o, 13 ~ 0.2o

quark:

1>>12>>23 >>13

12 ~ 34o, 23 ~ 38o, 13 ~ 9o

lepton:


Baryonic B Decays the parameters

  • B  baryon + antibaryon

  • B  baryon + antibaryon + meson

  • B  baryon + antibaryon + 


A baryon pair is allowed in the final state of the parameters

hadronic B decays.

In charm decay, Ds+→pn is the only allowed baryonic D decay. Its BR ~ 10-3 (CLEO)


2-body charmless baryonic B decays the parameters

Very rare !

CLEO

DLPHI

ARGUS

CLEO

ALEPH

CLEO

CLEO

Belle

Belle

BaBar

Belle

15


CY the parameters

CZ=Chernyak & Zhitnitsky (’90), CY= Cheng & Yang (’02)

What is the theory expectation of Br(B0 pp) ?

16


Talk presented at 7 the parameters th Particle Physics Phenomenology Workshop, 2007


LHCb (1308.0961) the parameters

Br(B0 pp)= (1.47+0.62+0.35-0.51-0.14)10-8

Br(Bs0 pp)= (2.84+2.03+0.85-1.08-0.18)10-8

3.3

first evidence

see the talk of Prisciandaro (22C1b)

LHCb (1307.6165) observed a resonance (1520) in B-ppK- decays

Br(B-(1520)p)= (3.9+1.0-0.90.10.3)10-7

(1520)pK-

The pQCD calculation of B0 pp is similar to the pQCD calculation of B→cp (46 Feynman diagrams) by X.G.He, T.Li, X.Q.Li, Y.M.Wang (’06)

Why is Br(B-(1520)p) >> Br(B0 pp) ?


Angular distribution the parameters

  • Measurement of angular distributions in dibaryon rest frame will provide further insight of the underlying dynamics

  • SD picture predict a stronger correlation of the meson with the antibaryon than to the baryon in B→B1B2M

B-→pp-

pp rest frame

B rest frame

-

p

u

b

p

-

p

p

B-

p

-

p

-

u

Belle(’08)

(’13)

p

p

-

p

19


- the parameters

Angular distribution in penguin-dominated B-ppK-

-

s

u

b

K-

K-

s

u

SD picture predicts a strong correlation between K- and p !

b

u

p

p

-

-

p

p

u

u

Belle(’04)

Belle: K- is preferred to move

collinearly with p in pp rest frame !

 a surprise in correlation

p

p

K-

_

p

BaBar(’05)

(’13)

BaBar measured Dalitz plot

asymmetry

unsolved enigma !

20


Angular distribution in B the parameters -p-

s

b

SD picture: Both  & p picks up energetic s and u quarks, respectively ⇒ on the average, pion has no preference for its correlation with  or p⇒a symmetric parabola that opens downward

-

B0

p

u

-

u

+

d

Tsai, thesis (’06)

_

Belle(’07): M.Z. Wang et al.

shows a slanted straight line

⇒another surprise !!

p

p

+

  • Correlation enigma occurs in penguin-dominated modes B→ppK, p

  • Cannot be explained by SD b→ sg* picture

  • Needs to be checked by LHCb & BaBar

  • Theorists need to work hard !

21


Radiative baryonic B decays the parameters

At mesonic level, bs electroweak penguin transition manifests in BK*. Can one see the same mechanism in baryonic B decays ?

  • Consider b pole diagram and apply HQS and static b quark limit to relate the tensor matrix element with b form factors

  • Br(B-p)  Br(B-0-) = 1.210-6

  • Br(B-0p)= 2.910-9

    Penguin-induced B-p and B-0- should be readily accessible to

    B factories

HYC,Yang (’02)

Belle [ Lee & Wang et al. PRL 95, 061802 (’05) ]

Br(B-p) = (2.45+0.44-0.380.22)10-6

Br(B-0p) < 4.610-6

first observation of bs in baryonic B decay

22


Extensive studies of baryonic B decays in Taiwan both experimentally and theoretically

Theory

Expt.

Belle group at NTU (Min-Zu Wang,…)

Chen, Chua, Geng, He, Hou, Hsiao, Tsai, Yang, HYC,…

B-→ppK-: first observation of charmless baryonic B decay (’01)

B→pp(K,K*,)

→p(,K)

→K

B→pp, , p (stringent limits)

Publication after 2000: (hep-ph)

0008079, 0107110, 0108068, 0110263, 0112245, 0112294, 0201015, 0204185, 0204186, 0208185, 0210275, 0211240, 0302110,0303079, 0306092, 0307307, 0311035, 0405283, 0503264, 0509235, 0511305, 0512335, 0603003, 0603070, 0605127, 0606036, 0606141, 0607061, 0607178, 0608328, 0609133, 0702249, PRD(05,not on hep-ph), 0707.2751, 0801.0022, 0806.1108, 0902.4295, 0902.4831, 1107.0801, 1109.3032, 1204.4771, 1205.0117, 1302.3331

B→p: first observation of b→s penguin in baryonic B decays (’04)

Publication after 2002:

15 papers (first author) so far: 7PRL, 2PLB, 6PRD; 2 in preparation

Taiwan contributes to 86% of theory papers


Direct CP violation experimentally and theoretically

in charm decays


CP violation in charm decays experimentally and theoretically

  • DCPV requires nontrival strong and weak phase difference

  • In SM, DCPV occurs only in singly Cabibbo-suppressed decays.

    It is expected to be very small in charm sector within SM

Amp = V*cdVud (tree + penguin) + V*csVus (tree’ + penguin)

No CP violation in D decays if they proceed only through tree diagrams

Penguin is needed in order to produce DCPV at tree & loop level

: strong phase

DCPV is expected to be the order of 10-3  10-5 !

25


Experiment experimentally and theoretically

Time-dependent CP asymmetry

Time-integrated asymmetry

LHCb: (11/14/2011) 0.92 fb-1based on 60% of 2011 data

  • ACPACP(D0 K+K-) – ACP(D0+-) = - (0.820.210.11)%

  • 3.5 effect: first evidence of CPV in charm sector

CDF: (2/29/2012) 9.7 fb-1

ACP= Araw(K+K-) - Araw(+-)= - (2.330.14)% - (-1.710.15)%

= - (0.620.210.10)% 2.7 effect

Belle: (ICHEP2012) 540 fb-1

ACP = - (0.870.410.06)%

see Mohanty’s talk (11/25)

26


World averages of LHCb + CDF + BaBar + Belle in 2012

aCPdir = -(0.6780.147)%, 4.6 effect

aCPind = -(0.0270.163)%

Theory estimate is much smaller than the expt’l measurement of |aCPdir |  0.7%  New physics ?

27

27


Chen, Geng, Wang [1206.5158] 2012

Delaunay, Kamenik, Perez, Randall [1207.0474]

Da Rold, Delaunay, Grojean, Perez [1208.1499]

Lyon, Zwicky [1210.6546]

Atwood, Soni [1211.1026]

Hiller, Jung, Schacht [1211.3734]

Delepine, Faisel, Ramirez [1212.6281]

Li, Lu, Qin, Yu [1305.7021]

Buccella, Lusignoli, Pugliese, Santorelli [1305.7343]

Isidori, Kamenik, Ligeti, Perez [1111.4987]

Brod, Kagan, Zupan [1111.5000]

Wang, Zhu [1111.5196]

Rozanov, Vysotsky [1111.6949]

Hochberg, Nir [1112.5268]

Pirtskhalava, Uttayarat [1112.5451]

Cheng, Chiang [1201.0785]

Bhattacharya, Gronau, Rosner [1201.2351]

Chang, Du, Liu, Lu, Yang [1201.2565]

Giudice, Isidori, Paradisi [1201.6204]

Altmannshofer, Primulando, C. Yu, F. Yu [1202.2866]

Chen, Geng, Wang [1202.3300]

Feldmann, Nandi, Soni [1202.3795]

Li, Lu, Yu [1203.3120]

Franco, Mishima, Silvestrini [1203.3131]

Brod, Grossman, Kagan, Zupan [1203.6659]

Hiller, Hochberg, Nir [1204.1046]

Grossman, Kagan, Zupan [1204.3557]

Cheng, Chiang [1205.0580]

28 theory papers !

28

28


Diagrammatic Approach 2012

All two-body hadronic decays of heavy mesons can be expressed in

terms of several distinct topological diagrams [Chau (’80); Chau, HYC(’86)]

T (tree)

A (W-annihilation)

E (W-exchange)

C (color-suppressed)

HYC, Oh (’11)

PA, PAEW

PE, PEEW

P, PcEW

S, PEW

All quark graphs are topological and meant to have all strong interactions encoded and hence they are not Feynman graphs. And SU(3) flavor symmetry is assumed.

29

29


Cabibbo-allowed decays 2012

For Cabibbo-allowed D→PP decays (in units of 10-6GeV)

T= 3.14 ± 0.06 (taken to be real)

C= (2.61 ± 0.08) exp[i(-152±1)o]

E= (1.53+0.07-0.08) exp[i(122±2)o]

A= (0.39+0.13-0.09) exp[i(31+20-33)o]

CLEO (’10)

2=0.39/d.o.f

Rosner (’99)

Wu, Zhong, Zhou (’04)

Bhattacharya, Rosner (’08,’10)

HYC, Chiang (’10)

  • Phase between C & T ~ 150o

  • W-exchange Eis sizable with a large phase  importance of 1/mcpower corrections

  • W-annihilaton A is smaller than Eand almost perpendicular to E

E

C

A

T

The great merit & strong point of this approach  magnitude and strong phase of each topological tree amplitude are determined

30


Tree-level direct CP violation 2012

DCPV can occur even at tree level

A(Ds+ K0+) =d(T + Pd+ PEd) + s(A + Ps+ PEs), p=V*cpVup

DCPV in Ds+ K0+ arises from interference between T & A

 10-4

DCPV at tree level can be reliably estimated in diagrammatic approach as magnitude & phase of tree amplitudes can be extracted from data

Larger DCPV at tree level occurs in decay modes with interference between T & C (e.g. Ds+K+) or C & E (e.g. D00)

31


Tree-level DCPV a 2012CP(tree) in units of per mille

10-3 > adir(tree) > 10-4

Largest tree-level DCPV

PP: D0K0K0, VP: D0’

aCP(tree) vanishes in

D0+-, K+K-

32


Short-distance penguin contributions are very small. How about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T  0.04 and PA / T  -0.02

Large LD contribution to PE can arise from D0 K+K- followed by a resonantlike final-state rescattering

It is reasonable to assume PE ~ E, PEP ~ EP, PEV ~ EV

Power corrections to P from PE via final-state rescattering cannot be larger than T


a about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T CPdir (10-3)

aCPdir= -0.1390.004% (I)

-0.1510.004% (II)

about 3.3 away from -(0.6780.147)%

A similar result aCPdir=-0.128% obtained by Li, Lu, Yu

see Hsiang-nan Li’s talk (11/25)

Even for PE  T aCPdir = -0.27%, an upper bound in SM

If aCPdir ~ -0.68%, it

is definitely a new physics effect !

34


Attempts for SM interpretation about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T

Golden, Grinstein (’89): hadronic matrix elements enhanced as in I=1/2 rule.

However, D data do not show large I=1/2 enhancement over I=3/2 one.

Moreover, |A0/A2|=2.5 in D decays is dominated by tree amplitudes.

Brod, Kagan, Zupan: PE and PA amplitudes considered

Pirtskhalava, Uttayarat : SU(3) breaking with hadronic m.e. enhanced

Bhattacharya, Gronau, Rosner : Pb enhanced by unforeseen QCD effects

Feldmann, Nandi, Soni : U-spin breaking with hadronic m.e. enhanced

Brod, Grossman, Kagan, Zupan: penguin enhanced

Franco, Mishima, Silvestrini: marginally accommodated

We have argued that power corrections to P from PE via final-state

rescattering cannot be larger than T


LHCb in 2013: about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T

ACP = - (0.340.150.10)% D* tagged

ACP = (0.490.300.14)% B D0X, muon tagged

- (0.150.16)% combination

See D. Tonelli’s talk (11/25)

World average: aCPdir = -(0.3330.120)%, 2.8

aCPind = (0.0150.052)%

Recall that aCPdir = -(0.6780.147)%, 4.6 in 2012 !

It appears that SM always wins !


Direct CP violation in about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T

charmless B decays


Direct CP asymmetries (2-body) about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T

LHCb

AKACP(K-0) – ACP(K-+)

K puzzle: AK is naively expected to vanish

38

38


A about power corrections to QCD penguin ? SD weak penguin annihilation is also very small; typically, PE / T CP(B- K-)

Expt:

Theory:

LHCb observed CP violation in B-K-K+K- but not around  resonance

arXiv:1306.1246

LHCb (1309.3742) obtained ACP = (2.22.10.9)%


In heavy quark limit, decay amplitude is factorizable, expressed in terms of form factors and decay constants.

sign

See Beneke & Neubert (’03) for mb results

40

40


A( expressed in terms of form factors and decay constants. B0K-+) ua1+c(a4c+ra6c)

Im4c  0.013  wrong sign for ACP

4c

charming penguin, FSI penguin annihilation

1/mb corrections

penguin annihilation

41


New CP puzzles in QCDF expressed in terms of form factors and decay constants.

Penguin annihilation solves CP puzzles for K-+,+-,…, but in the meantime introduces new CP puzzles for K-, K*0, …

Also true in SCET with penguin annihilation replaced by charming penguin

42

42

42


All “problematic” modes receive contributions from expressed in terms of form factors and decay constants. uC+cPEW

PEW  (-a7+a9), PcEW  (a10+ra8), u=VubV*us, c=VcbV*cs

AK puzzle can be resolved by having a large complex C

(C/T  0.5e–i55 ) or a large complex PEW or the combination

AK 0 if C, PEW, A are negligible

 AK puzzle

o

Large complex C Charng, Li, Mishima; Kim, Oh, Yu; Gronau, Rosner; …

Large complex PEW needs New Physics for new strong & weak phases

Yoshikawa; Buras et al.; Baek, London;

G. Hou et al.; Soni et al.; Khalil et al;…

43


The two distinct scenarios can be tested in tree-dominated modes where ’cPEW << ’uC. CP puzzles of -, 00 & large rates of 00, 00 cannot be explained by a large complex PEW

00 puzzle: ACP=(4324)%, Br = (1.910.22)10-6

44

44


Direct CP asymmetries (3-body) modes where ’

LHCb found evidence of inclusive CP asymmetry in

B-+--, K+K-K-, K+K--

Large asymmetries observed in localized regions of p.s.

ACP(KK) = -0.6480.0700.0130.007 for mKK2 <1.5 GeV2

ACP(KKK) = -0.2260.0200.0040.007 for 1.2< mKK, low2 <2.0 GeV2, mKK, high2 <15 GeV2

ACP() = 0.584+0.082+0.027+0.007 for m, low2 <0.4 GeV2, m, high2 > 15 GeV2

ACP(K) = 0.6780.0780.0320.007 for 0.08< m, low2 <0.66 GeV2, mK2 <15 GeV2

45


Correlation: modes where ’

ACP(K-K+K-)  – ACP(K-+-), ACP(-K+K-)  – ACP(-+-)

  • Relative signs between CP asymmetries of K-K+K- & -+-, -K+K- & K-+- are consistent with U-spin prediction.

  • It has been conjectured that CPT theorem & final-state rescattering of +- K+K- may play important roles

Zhang, Guo, Yang [1303.3676]

Bhattacharya, Gronau, Rosner [1306.2625]

Xu, Li, He [1307.7186]

Bediaga, Frederico, Lourenco [1307.8164]

Cheng, Chua [1308.5139]

Zhang, Guo, Yang [1308.5242]

Lesniak, Zenczykowski [1309.1689]

Xu, Li, He [1311.3714]


Conclusion of this section modes where ’

  • CP asymmetries are the ideal places to discriminate between different models.

  • In QCDF one needs two 1/mb power corrections (one to penguin annihilation, one to color-suppressed tree amplitude) to explain decay rates and resolve CP puzzles

  • Can we understand the correlation ?

    ACP(K-K+K-)  – ACP(K-+-), ACP(-K+K-)  – ACP(-+-)


Conclusions modes where ’

  • To expand Wolfenstein parametrization to higher order of , it is important to use  &  parameters order of unity.

  • First evidence of charmless baryonic B decays: time for updated theory studies. Correlation puzzle in penguin-dominated decays needs to be resolved.

  • DCPV in charm decays is studied in the diagrammatic approach. It can be reliably estimated at tree level. Our prediction is aCP = -(0.1390.004)%


Backup Slides modes where ’


modes where ’: strong phase

To accommodate aCP one needs P/T~ 3 for maximal strong phase, while it is naively expected to be of order s/

Bhattacharya, Gronau, Rosner Brod, Grossman, Kagan, Zupan

Can penguin be enhanced by some nonperturbative effects or unforeseen QCD effects ?

We have argued that power corrections to P from PE via final-state

rescattering cannot be larger than T

50


In D modes where ’ decays

( 22.40.1 in K )

In absence of penguin contribution & SU(3) breaking, this ratio is predicted to be 3.8, larger than the expt’l result. This means P should contribute destructively to A0/A2 .

In kaon decays, the predicted ratio due to tree amplitudes is too small compared to experiment  large enhancement of penguin matrix element.


New Physics interpretation modes where ’

Before LHCb: Grossman, Kagan, Nir (’07)

Bigi, Paul, Recksiegel (’11)

After LHCb :

  • Model-independent analysis of NP effects Isidori, Kamenik, Ligeti, Perez

  • Tree level (applied to some of SCS modes)

  • FCNC Z

  • FCNC Z’ (a leptophobic massive gauge boson)

  • 2 Higgs-doublet model: charged Higgs

  • Color-singlet scalar

  • Color-sextet scalar (diquark scalar)

  • Color-octet scalar

  • 4th generation

Giudice, Isidori, Paradisi; Altmannshofer, Primulando, C. Yu, F. Yu

Wang, Zhu; Altmannshofer, Primulando, C. Yu, F. Yu

Altmannshofer et al.

Hochberg, Nir

Altmannshofer et al; Chen, Geng, Wang

Altmannshofer et al.

Rozanov, Vysotsky; Feldmann, Nandi, Soni


NP models are highly constrained from D- modes where ’D mixing, K-K mixing, ’/,… Tree-level models are either ruled out or in tension with other experiments.

Loop level (applied to all SCS modes)

Large C=1 chromomagnetic operator with large imaginary coefficient

is least constrained by low-energy data and can accommodate large ACP.<PP|O8g|D> is enhanced by O(v/mc). However, D0-D0 mixing induced by O8g is suppressed by O(mc2/v2). Need NP to enhance c8g by O(v/mc)

Giudice, Isidori, Paradisi

It can be realized in SUSY models

  • gluino-squark loops

  • new sources of flavor violation from disoriented A terms, split families

  • trilinear scalar coupling

  • RS flavor anarchy warped extra dimension models

Grossman, Kagan, Nir

Giudice, Isidori, Paradisi

Hiller, Hochberg, Nir

Delaunay, Kamenik, Perez, Randall


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