Flavor , Charm , CP Related Physics. HaiYang 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
HaiYang Cheng
Academia Sinica, Taipei
PASCOS, Taipei
November 22, 2013
Outline:
See the talk of Rodrigues (11/21)
Quark & lepton mixing matrices
CP Violation in Standard Model
VCKM is the only source of CPV in flavorchanging 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 :
4
Maiani (’77)
advocated by PDG (’86) as a standard parametrization.
However, the coefficient of the imaginary part of Vcb and Vts is O(102) rather than O(103) as s23 102
In 1984 LingLie Chau and WaiYee Keung proposed a new parametrization
1>>12>>23 >>13
s13 ~ 103
The same as VMaiani except for the phases of t & b quarks. The imaginary part is O(103). This new CKM(ChauKeungMaiani) matrix is adapted by PDG as a standard parametrization since 1988.
Some simplified parametrizations
Mixing matrix is expressed in terms of , A ~ 0.8, and . Imaginary part = A3 103. However, this matrix is valid only up to 3
& 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 ei() and replacing A, , , by A’, ’ , ’ and ’
Look quite differently from those 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 ~ A3
Now Vub ~ 0.00351, Vcb ~ 0.0412 Vub ~ 2 Vcb~ A4
We define & of order unity
9
Most of the discrepancies are resolved via the definition of the parameters , of order unity
Ahn, HYC, Oh
arXiv:1106.0935
10
Lepton mixing matrix
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
12 ~ 13o, 23 ~ 2.4o, 13 ~ 0.2o
quark:
1>>12>>23 >>13
12 ~ 34o, 23 ~ 38o, 13 ~ 9o
lepton:
Baryonic B Decays
A baryon pair is allowed in the final state of
hadronic B decays.
In charm decay, Ds+→pn is the only allowed baryonic D decay. Its BR ~ 103 (CLEO)
2body charmless baryonic B decays
Very rare !
CLEO
DLPHI
ARGUS
CLEO
ALEPH
CLEO
CLEO
Belle
Belle
BaBar
Belle
15
CY
CZ=Chernyak & Zhitnitsky (’90), CY= Cheng & Yang (’02)
What is the theory expectation of Br(B0 pp) ?
16
Talk presented at 7th Particle Physics Phenomenology Workshop, 2007
LHCb (1308.0961)
Br(B0 pp)= (1.47+0.62+0.350.510.14)108
Br(Bs0 pp)= (2.84+2.03+0.851.080.18)108
3.3
first evidence
see the talk of Prisciandaro (22C1b)
LHCb (1307.6165) observed a resonance (1520) in BppK decays
Br(B(1520)p)= (3.9+1.00.90.10.3)107
(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
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

Angular distribution in penguindominated BppK

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 Bp
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
+
21
Radiative baryonic B decays
At mesonic level, bs electroweak penguin transition manifests in BK*. Can one see the same mechanism in baryonic B decays ?
Penguininduced Bp and B0 should be readily accessible to
B factories
HYC,Yang (’02)
Belle [ Lee & Wang et al. PRL 95, 061802 (’05) ]
Br(Bp) = (2.45+0.440.380.22)106
Br(B0p) < 4.6106
first observation of bs in baryonic B decay
22
Extensive studies of baryonic B decays in Taiwan both experimentally and theoretically
Theory
Expt.
Belle group at NTU (MinZu 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: (hepph)
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 hepph), 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
in charm decays
CP violation in charm 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 103 105 !
25
Experiment
Timedependent CP asymmetry
Timeintegrated asymmetry
LHCb: (11/14/2011) 0.92 fb1based on 60% of 2011 data
CDF: (2/29/2012) 9.7 fb1
ACP= Araw(K+K)  Araw(+)=  (2.330.14)%  (1.710.15)%
=  (0.620.210.10)% 2.7 effect
Belle: (ICHEP2012) 540 fb1
ACP =  (0.870.410.06)%
see Mohanty’s talk (11/25)
26
World averages of LHCb + CDF + BaBar + Belle in 2012
aCPdir = (0.6780.147)%, 4.6 effect
aCPind = (0.0270.163)%
Theory estimate is much smaller than the expt’l measurement of aCPdir  0.7% New physics ?
27
27
Chen, Geng, Wang [1206.5158]
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
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Diagrammatic Approach
All twobody hadronic decays of heavy mesons can be expressed in
terms of several distinct topological diagrams [Chau (’80); Chau, HYC(’86)]
T (tree)
A (Wannihilation)
E (Wexchange)
C (colorsuppressed)
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
Cabibboallowed decays
For Cabibboallowed D→PP decays (in units of 106GeV)
T= 3.14 ± 0.06 (taken to be real)
C= (2.61 ± 0.08) exp[i(152±1)o]
E= (1.53+0.070.08) exp[i(122±2)o]
A= (0.39+0.130.09) exp[i(31+2033)o]
CLEO (’10)
2=0.39/d.o.f
Rosner (’99)
Wu, Zhong, Zhou (’04)
Bhattacharya, Rosner (’08,’10)
HYC, Chiang (’10)
E
C
A
T
The great merit & strong point of this approach magnitude and strong phase of each topological tree amplitude are determined
30
Treelevel direct CP violation
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
104
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. D00)
31
Treelevel DCPV aCP(tree) in units of per mille
103 > adir(tree) > 104
Largest treelevel DCPV
PP: D0K0K0, VP: D0’
aCP(tree) vanishes in
D0+, K+K
32
Shortdistance 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 finalstate rescattering
It is reasonable to assume PE ~ E, PEP ~ EP, PEV ~ EV
Power corrections to P from PE via finalstate rescattering cannot be larger than T
aCPdir (103)
aCPdir= 0.1390.004% (I)
0.1510.004% (II)
about 3.3 away from (0.6780.147)%
A similar result aCPdir=0.128% obtained by Li, Lu, Yu
see Hsiangnan 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
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 : Uspin 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 finalstate
rescattering cannot be larger than T
LHCb in 2013:
ACP =  (0.340.150.10)% D* tagged
ACP = (0.490.300.14)% B D0X, muon tagged
 (0.150.16)% combination
See D. Tonelli’s talk (11/25)
World average: aCPdir = (0.3330.120)%, 2.8
aCPind = (0.0150.052)%
Recall that aCPdir = (0.6780.147)%, 4.6 in 2012 !
It appears that SM always wins !
Direct CP violation in
charmless B decays
Direct CP asymmetries (2body)
LHCb
AKACP(K0) – ACP(K+)
K puzzle: AK is naively expected to vanish
38
38
ACP(B K)
Expt:
Theory:
LHCb observed CP violation in BKK+K but not around resonance
arXiv:1306.1246
LHCb (1309.3742) obtained ACP = (2.22.10.9)%
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(B0K+) ua1+c(a4c+ra6c)
Im4c 0.013 wrong sign for ACP
4c
charming penguin, FSI penguin annihilation
1/mb corrections
penguin annihilation
41
New CP puzzles in QCDF
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 uC+cPEW
PEW (a7+a9), PcEW (a10+ra8), 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 treedominated modes where ’cPEW << ’uC. CP puzzles of , 00 & large rates of 00, 00 cannot be explained by a large complex PEW
00 puzzle: ACP=(4324)%, Br = (1.910.22)106
44
44
Direct CP asymmetries (3body)
LHCb found evidence of inclusive CP asymmetry in
B+, K+KK, K+K
Large asymmetries observed in localized regions of p.s.
ACP(KK) = 0.6480.0700.0130.007 for mKK2 <1.5 GeV2
ACP(KKK) = 0.2260.0200.0040.007 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) = 0.6780.0780.0320.007 for 0.08< m, low2 <0.66 GeV2, mK2 <15 GeV2
45
Correlation:
ACP(KK+K) – ACP(K+), ACP(K+K) – ACP(+)
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
ACP(KK+K) – ACP(K+), ACP(K+K) – ACP(+)
Conclusions
Backup Slides
: 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 finalstate
rescattering cannot be larger than T
50
In D decays
( 22.40.1 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
Before LHCb: Grossman, Kagan, Nir (’07)
Bigi, Paul, Recksiegel (’11)
After LHCb :
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 DD mixing, KK mixing, ’/,… Treelevel 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 lowenergy data and can accommodate large ACP.<PPO8gD> is enhanced by O(v/mc). However, D0D0 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
Grossman, Kagan, Nir
Giudice, Isidori, Paradisi
Hiller, Hochberg, Nir
Delaunay, Kamenik, Perez, Randall