[PPT] - Quark-sector CP violations and beyond Youngjoon Kwon Yonsei PowerPoint Presentation

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Quark-sector CP violations and beyond

Youngjoon Kwon

Yonsei University

1st T2HKK Workshop @ SNU, Nov. 21-22, 2016

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Outline

Introduction & Motivation CP violations in the quark sector Outlook

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3

5

The three frontiers

Flavor Physics

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Energy vs. Intensity Frontiers

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Intensity Frontier is complementary to the Energy Frontier If LHC finds NP

* precision flavor input is essential to further clarify those discoveries

Even if no new NP is found

* high-statistics flavor sector measurements (on b, c, and τ) can provide beyond-TeV-scale probe for NP

SuperKEKB KEKB LHC Tevatron

(gNP/g)2 MNP[TeV] 10

1

1 10 10 2 1 10 10

2

favor-violating coupling NP mass scale

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Flavor Physics Grand Slam

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Why interested in CP violations?

Without CPV, we cannot exist. 1964 Cronin, Fitch, et al.

Discovery of CPV by observing

1967 A. Sakharov, 3 conditions

baryon # non-conservation
C & CP violation
not in thermal equilibrium

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7

1/500 in 0.17βγ

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CPV in the Standard Model

Kobayashi-Maskawa mechanism

provides CP violation within SM via quark mixing matrix

(“CKM matrix”) in charged-current weak interactions

predicts large (~O(10%)) CP violations in the B0 mesons
experimental tests of the unitarity of CKM matrix

CP violations in the strong sector? Since neutrinos also mix (maximally), CPV in neutrinos is also a possibility; but no experimental signatures yet

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L = θ 1 16π2 F a

µν ˜

F µνa

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in mixing in decays (“Direct CP violation”) via interference between mixing and decay (t-dependent)

Three ways for CPV

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ASL = Ŵ( ¯ M → X ℓ+νℓ) − Ŵ(M → X ℓ− ¯ νℓ) Ŵ( ¯ M → X ℓ+νℓ) − Ŵ(M → X ℓ− ¯ νℓ)

W

t

g

s

W

Vub

fcp

B0 B0

=

B0 B0

fcp

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> 5σ signatures of CPV (1)

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Indirect CP violation in K → ππ and K → πℓν decays, and in the KL → π+π−e+e−

decay, is given by |ϵ| = (2.228 ± 0.011) × 10−3 . (13.1)

Direct CP violation in K → ππ decays is given by

Re(ϵ′/ϵ) = (1.65 ± 0.26) × 10−3 . (13.2)

CP violation in the interference of mixing and decay in the tree-dominated b → c¯

cs transitions, such as B0 → ψK0, is given by (we use K0 throughout to denote results that combine KS and KL modes, but use the sign appropriate to KS): SψK0 = +0.691 ± 0.017 . (13.3)

SD(∗)

CP h0 = +0.63 ± 0.11 ,

first Belle-BaBar joint analysis

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11

2008

Events / 0.5 ps 50 100 150 200 250 300 350 400 t (ps) ∆

6
4
2

2 4 6 Asymmetry

0.6
0.4
0.2

0.2 0.4 0.6

Belle, PRL (2012)

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CKM Unitarity Triangle fit (now) CKM fit (as of 2001)

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> 5σ signatures of CPV (2)

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Sψπ0 = − 0.93 ± 0.15 , SD+D− = − 0.98 ± 0.17 . SD∗+D∗− = − 0.71 ± 0.09 . SφK0 = + 0.74 +0.11

−0.13 ,

Sη′K0 = + 0.63 ± 0.06 , Sf0K0 = + 0.69 +0.10

−0.12 ,

SK+K−KS = + 0.68 +0.09

−0.10 ,

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14

Events / (1.5 ps)

50 100 150 200 250 300

q = +1 q = -1

t (ps) ∆

7.5
5
2.5

2.5 5 7.5

B

+ N

B

N

B

N

B

N

0.5

0.5

(a) (b)

)

2

Events / (0.0025 GeV/c

50 100 150 200 250 300 350 400

)

2

(GeV/c

bc

M 5.24 5.25 5.26 5.27 5.28 5.29 5.3 Residuals Normalised

2

2

(a)

Events / (0.1)

10

2

10

3

10

π K/ +

L 0.2 0.4 0.6 0.8 1 Residuals Normalised

2

2

(c)

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> 5σ signatures of DCPV

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Direct CP violation in the B0 → K−π+ mode is given by

AB0→K−π+ = −0.082 ± 0.006 . (13.14)

Direct CP violation in B+ → D+K+ decays (D+ is the CP-even neutral D state) is

given by AB+→D+K+ = +0.195 ± 0.027 . (13.15)

Direct CP violation in the B0

s → K+π− mode is given by

AB0

s→K+π− = +0.26 ± 0.04 .

(13.16)

Direct CP violation in B+ → K+K−π+ decays is given by

AB+→K+K−π+ = −0.118 ± 0.022 . (13.17)

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The “Kπ puzzle”

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a

b B+, B0 u p0, p– u K+, p+ u u B+ b u

c

p+, K+ p0 d, s u W B+ u, d u, d p+, K+ u b u p0 d, s

b

u u B+, B0

d

u, d u, d b s, d u, d u, d p0, p– W W Z W K+, p+ s, d g

250 500 750

a K–p+ b K+p–

Mbc (GeV/c2) Entries per 2 MeV/c2 100 200 300 5.2 5.25

c K−p0

5.2 5.25

d K+p0

Belle, Nature 452, 20 (2008)

AB0→K−π+ = −0.082 ± 0.006 , AB−→K−π0 = 0.040 ± 0.021

from HFAG (2016)

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CPV in Kaons:

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10 20 30 (x10-4)

4 . 7 1 3 7 E ± 5.9 . 3 2 1 3 A N ± 6.5 7 . 4 1 8 4 A N ± 2.2 2 . 9 1 V E T K ± 2.1 8 . 6 1 . e v A d l r

W

w e N ± 1.4

16.6 ± 2.3

ðKL ! þÞ=ðKS ! þÞ ðKL ! 00Þ=ðKS ! 00Þ Þ Þ ¼

þ

00

2

ð ! Þ ð 1 þ 6 Reð0=Þ:

25 cm 120 140 160 180 Z = Distance from kaon production target (meters) Beams Regenerator Beam Vacuum Beam Analysis Magnet Regenerator Drift Chambers Trigger Hodoscope Muon Veto Steel CsI Mask Anti Photon Vetoes Photon Vetoes CA

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CPV in Kaons:

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Energy (MeV) Range (cm)

E787/E949

This analysis E949-PNN1 E787-PNN2 E787-PNN1 Simulation

10 15 20 25 30 35 40 45 50 60 70 80 90 100 110 120 130 140 150

BNL E787/E949 7 events observed High-precision results expected from NA62

PRL 101, 191802 (2008)

Not enough events to measure ACP
contribution from intermediate

charm quark is not negligible, and constitutes a source of hadronic uncertainty

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CPV in Kaons:

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best limit by KEK E391 KOTO goal

to observe 3.5 SM signal in 3 years

running

(cm)

vtx

Z

200 250 300 350 400 450 500 550 600

(GeV/c)

T

P

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

PHYSICAL REVIEW D 81, 072004 (2010)

B(KL → π0νν) = κL[X(m2

t /m2 W )]2A4η2 ,

a very clean CPV mode to extract a CKM parameter η

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CPV in charm

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no evidence for charm CPV yet direct CPV can be isolated by

af ≡ ∞ Γ(D0

phys(t) → f)dt −

∞ Γ(D0

phys(t) → f)dt

∞ Γ(D0

phys(t) → f)dt +

∞ Γ(D0

phys(t) → f)dt

f = ad f + am f + ai f

ad

f = 2rf sin φf sin δf

am = −y 2

q

p

−
p

q

cos φD

ai = x 2

q

p

+
p

q

sin φD

LHCb, JHEP 1407, 041 (2014)

∆aCP ≡ aK+K− − aπ+π− = ad

K+K− − ad π+π−

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CPV in charm

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an honorable mention

)

2

) (GeV/c

+

π

S

M(K

1.8 1.9

)

2

Events/(1 MeV/c

4

10

5

10

)

2

) (GeV/c

π

S

M(K

1.8 1.9

)

2

Events/(1 MeV/c

4

10

5

10

CMS

0.5 1

CP

+

π

S

K →

+

D

A

0.015
0.01
0.005

0.005

|

+

D c.m.s.

θ |cos

0.5 1

FB

+

D

A

0.04
0.03
0.02
0.01

PRL 109, 021601 (2012)

Belle

A

Dþ!K0

Sþ

CP

¼ ð0:363 0:094 0:067Þ%. measurement supersedes our previous determination

the only evidence for CPV

in charm sector

consistent with what’s

expected from CPV in K0

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CPV beyond the quark sector

Why beyond?

CPV in quark sector is consistent with KM mechanism
NP contribution of O(0.1) can still be accommodated
But, CPV via KM is far smaller than BAU, by O(10−10)

CP violations in leptons & leptogenesis

many people’s favorite hypothesis for BAU
one of main motivations for T2HKK

CP violations via EDM

or does it call for an axion?

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future prospects for CPV in quarks

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the next Luminosity Frontier

SuperKEKB is the next luminosity frontier

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SuperKEKB

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The super B-factory at KEK (2018 start)

A planned 40-fold increase in luminosity over KEKB (target: 8x1035

cm-2s-1 instantaneous, 50ab-1 integrated), due to major upgrades: ○ “Nano-beam” scheme (below) ○ Doubled beam currents ○ (large number of upgrades to RF, magnet, vacuum, etc. systems)

First turns Feb. 10, 2016! Exciting times!

See Y. Onishi, ICHEP highlights, 8/08 12:10

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Belle II major upgrades

5 Belle II at ICHEP:

Detectors: DEPFET: L. Andricek, Poster 8th 18:30 SVD: A. Paladino, Detector 4th 17:00 EMC: Y. Jin, Poster 6th 18:00 iTOP: A. Schwartz, Detector 6th 14:30 iTOP: K. Inami, Poster 6th 18:00 CPU: M. Schram, Computing 4th 12:50 Physics: Prospects: B. Fulsom, Flavor 5th 14:30 Dark: G. Inguglia, BSM 4th 17:40 Bottomonia: K. Miyabayashi, Poster 6th 18:00

Belle II

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Belle II milestones

Phase 1 (Feb. 2016)

beam commissioning + beam background measurements

Phase 2 (Dec. 2017)

Detector in place without VXD+PXD

Phase 3 (Nov. 2018)

Full physics run

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adapted from

Belle II vs. LHCb

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complementarity

(or competition!)

at a glance

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Epilogue

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“Imagine if Fitch and Cronin had stopped at the 1% level, how much physics would have been missed” (A. Soni) “A special search at Dubna was carried out by Okonov and his group. They did not find a single KL → π+ π– event among 600 decays into charged particles (Anikira et al., JETP 1962). At that stage the search was terminated by the administration

f the lab. The group was unlucky.” (L. Okun)
Remember BF(KL → π+π–) ~ 2x10–3

“We shall not cease from exploration” (T. S. Eliot)

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Thank you!

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more materials

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Driving questions for Belle II

(1) Are there any new CPV phases? (2) Any right-handed currents from NP? (3) Quark FCNC beyond the SM? New operators with quarks enhanced by NP? (4) Sources of LFV from NP? (5) Any more higgs? (e.g. H+) (6) Understanding exotic QCD states? (7) Hidden dark sector? …

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Driving questions for Belle II (1)

Are there any new CPV phases?

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Check ∆S ≡ sin 2φ1,eff(b → s¯ ss) − sin 2φ1(b → c¯ cs)

dominated by vertex resolution, which will improve: 61→ ∼18 µm

B0→ J/ψ K0 B0→ φ K0 B0→ η’ K0 B0→ K0K0K0

vs.

δ sin 2φ1 δSsq¯

q

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Are there any new CPV phases?

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Check ∆S ≡ sin 2φ1,eff(b → s¯ ss) − sin 2φ1(b → c¯ cs)

CPV & mixing

Firm SM upper bound required

sqq ccs

➔ good enough to test theory models

δ(Sb→s) ∼ 0.012 @ 50 ab−1

Driving questions for Belle II (1)

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Direct CP asymmetry in B ➔ K π

* currently, > 5σ deviation from naive SM expectation * the ‘sum rule’ can be put on a stringent test with Belle II, with crucial inputs from neutral mode

37 Gronau, PLB 627, 82 (2005); Atwood & Soni, PRD 58, 036005 (1998):

A(K0π0) A(K0π+)

measured (world avg) expected (sum rule) A(K0π0) = 0.006± 0.06 A(K0π+) = -0.015± 0.019 A(K+π0) = 0.040± 0.021 A(K+π-) = -0.082± 0.006

factories now (~1.4 ab ): B factories now (~1.4 ab-1)

Driving questions for Belle II (1′)

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Direct CP asymmetry in B ➔ K π

* currently, > 5σ deviation from naive SM expectation * the ‘sum rule’ can be put on a stringent test with Belle II, with crucial inputs from neutral mode

38 Gronau, PLB 627, 82 (2005); Atwood & Soni, PRD 58, 036005 (1998):

discrepancy apparent; ma significant already with ∼10 ab

Note: main K0π0 systematic (t

A(K ) A(K0

A(K0π0)

A(K0π+)

expected error expected (sum rule)

discrepancy is apparent; can be significant already with ∼10 ab-1 Note: main K0π0 systematic (tag-side interference) is reducible

B factory at 50 ab-1, with today’s central values:

Driving questions for Belle II (1′)

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Any right-handed currents from NP?

γL bR sL

helicity flip ∝ mb ~ 4.8 GeV

γR bL sR

h e l i c i t y f l i p ∝ ms ~ . 1 G e V

γR γL sR bL bR sL

Do not interfere for CPV Interfere for CPV SM favored SM disfavored, enhanced with RH current

SK0

Sπ0γ = −2ms

mb sin 2φ1 ∼ −0.03

In SM, one naively expects: In a L-R symmetric model,

SK0

Sπ0γ ∼ 0.5

can be probed by t-dep. CP asymmetry with B0 → K0

Sπ0γ

Driving questions for Belle II (2)

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S = −0.16 ± 0.22, C = −0.04 ± 0.14

mostly statistics limited

sin(2φ1)K0 π0 γ! gluino mass (TeV) [tanβ=30]! mSUGRA SU(5) SUSY GUT MSSM+U(2)

G. Buchalla et al., EPJC 57, 309 (2008)

value of S can discriminate among SUSY- breaking mechanisms

σ(SK∗γ) ∼ 0.09 @ 5 ab−1 ∼ 0.03 @ 50 ab−1 Any right-handed currents from NP?

Driving questions for Belle II (2)

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A. J. Schwartz

FPCP 2014, Marseilles, France Belle II Physics Prospects 42

! CCP(Ks π0γ) = -0.07 ±0.12 SCP(Ks π0γ) = -0.15 ±0.20 ! 0.10 (5 fb-1) ! 0.04 (50 fb-1)

1.0 2.0

pβ(sinθ)v [GeV/c]

Belle Belle II

σ[mm]

sin b a p

ν

σ β θ = +

Pβ(sinθ) v [GeV/c]

σ[mm]

1.0 2.0 Belle Belle II

What Belle II does to improve SKSπ0γ