Akar BLOIS 20160531 - CERN · Outline Simon Akar • Physics motivations • Mixing and CP...
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CP violation in B and charm decays Simon Akar 1 on behalf of the LHCb Collaboration 1 CPPM, Aix-Marseille Université CNRS/IN2P3, Marseille, France 28 th Rencontres de Blois Blois, France, 29/05-03/06 2016
Transcript of Akar BLOIS 20160531 - CERN · Outline Simon Akar • Physics motivations • Mixing and CP...
CP violation in B and charm decays
Simon Akar1 on behalf of the LHCb Collaboration
1CPPM, Aix-Marseille Université CNRS/IN2P3, Marseille, France
28th Rencontres de Blois Blois, France, 29/05-03/06 2016
Outline
Simon Akar
• Physics motivations
• Mixing and CP violation in charm
• Constraints on the CKM angle γ
• CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
• Summary & conclusions
2Blois 16' - CP violation in B and charm decays @ LHCb
1
Physics motivations
Quark mixing in the Standard Model (SM) described by the CKM matrix:
• CKM theory is highly predictive ‣ huge range of phenomena over a large energy interval
predicted using only 4 parameters (+ GF, mq and QCD)
• CKM matrix is hierarchical ‣ CKM structure not necessarily replicated in extended theories
→ strong constraints on New Physics (NP) models
• CKM mechanism introduces CP violation and neutral meson mixing phenomena ‣ The presence of new heavy particles exchanged in virtual loops could
introduce additional phases altering the corresponding measurements (NP contributions to tree-level processes also possible in some models)
CKM phenomenology
Simon Akar 4Blois 16' - CP violation in B and charm decays @ LHCb
2
Mixing and CP violation in charm
‣ Charm mixing, although expected to be very small in the SM compared to other neutral mesons, is established
‣ Any significant enhancement of mixing or CP violation in charm would be an indication of NP
‣ Here the knowledge of the initial flavour is needed Two methods used:
Motivations and ingredients
Simon Akar 6Blois 16' - CP violation in B and charm decays @ LHCb
0 1 2 3 4
Inte
nsity
0
0.5
1
y = 0.997x = -0.946: 0K(a)
0 1 2 3 4
-610
-410
-210
1
y = 0.0075x = 0.0063: 0D(b)
tΓ0 1 2 3 4
Inte
nsity
0
0.5
1
y = 0.005x = 0.773: 0B(c)
tΓ0 1 2 3 40
0.5
1
y = 0.046x = 25.194: sB(d)
K0
B0
0 1 2 3 4
Inte
nsity
0
0.5
1
y = 0.997x = -0.946: 0K(a)
0 1 2 3 4
-610
-410
-210
1
y = 0.0075x = 0.0063: 0D(b)
tΓ0 1 2 3 4
Inte
nsity
0
0.5
1
y = 0.005x = 0.773: 0B(c)
tΓ0 1 2 3 40
0.5
1
y = 0.046x = 25.194: sB(d) Bs
0
D0
Muon tag: (B − → D0 𝝁−X)Pion tag: (prompt D*＋ → D0
π＋)
2
Mixing and CP violation in charm
‣ First observation of D0 —D̅ 0
oscillations in D0 → K+π−π+π−
arXiv:1602.07224 [hep-ex] Full Run1 data: 3 fb-1NEW!
‣ Tagging D0 with pion tag method using prompt D*+
→ D0 π+ decays
‣ Interference between right sign (RS) Cabibbo favored (D0 → K−π+π−π+) and wrong sign (WS) doubly Cabibbo suppressed (D0 → K+π−π+π−) amplitudes
- Fit for Δ∆m = m(K+π−π+π−πs±) − m(K+π−π+π−)
Simon Akar 8Blois 16' - CP violation in B and charm decays @ LHCb
]2c [MeV/m∆140 145 150 155
)2 cCa
ndid
ates
/ (0
.1 M
eV/
00.2
0.40.60.8
1
1.21.41.6
610×
RS candidates
Fit
Background
LHCb
]2c [MeV/m∆140 145 150 155
)2 cCa
ndid
ates
/ (0
.1 M
eV/
0123456789
310×
WS candidates
Fit
Background
LHCb
First observation of D0 — D̅ 0
oscillations in D0 → K+π−π+π−arXiv:1602.07224 [hep-ex]
‣ Time dependent ratio of WS over RS amplitudes, R(t):
‣ First observation of D0 — D0̅
mixing in a decay other than D → Kπ
‣ Using (x,y) as input from HFAG, can obtain the amplitude ratio and phase: rDK3π , 𝛿D
K3π - Important input to γ combination
Simon Akar 9Blois 16' - CP violation in B and charm decays @ LHCb
τt /2 4 6 8 10 12
WS/
RS
3
3.5
4
4.5
5
5.5
63−10×
LHCb
DataUnconstrained fitNo-mixing fit
First observation of D0 — D̅ 0
oscillations in D0 → K+π−π+π−arXiv:1602.07224 [hep-ex]
2
Mixing and CP violation in charm
‣ First observation of D0 —D̅ 0
oscillations in D0 → K+π−π+π−
arXiv:1602.07224 [hep-ex] Full Run1 data: 3 fb-1
‣ Search for CP violation in D0 → K+K− and D0 → π+π− arXiv: 1602.03160 [hep-ex] Full Run1 data: 3 fb-1NEW!
‣ Tagging D0 with pion tag method using prompt D*+
→ D0 π+ decays
‣ Fit for 𝛅m = m(D*+ ) − m(D0
→ f ) with f = K+K− or f = π+π− and compute the asymmetry:
‣ After correcting for detection and production asymmetries (details in back-up ):
- World’s most precise measurement of CP asymmetry in D0 → K+K− and D0 → π+π− decays!
- Consistent with no CP violation
Search for CP violation in D0 → K+K− and D0 → π+π−
Simon Akar 11Blois 16' - CP violation in B and charm decays @ LHCb
arXiv:1602.03160 [hep-ex]
5−4−3−2−1−012345
10
δm (MeV/c2)5
0
100
200
300
400
500
600
310×
LHCb + → K K0D
Candidates
e-5-4-3-2-1012345
δm (MeV/c2)5 10
0
50
100
150
200LHCb + → π π−0D
Can
dida
tes /
( 0.
05 M
eV/c
2 ) ×103
�ACP ⌘ ACP (K+K�)�ACP (⇡
+⇡�)
= (�0.10± 0.08 (stat)± 0.03 (syst))%
ACP (f) =N
�D⇤+ ! D0(f)⇡+
s
��N
�D⇤� ! D0(f)⇡�
s
�
N�D⇤+ ! D0(f)⇡+
s�+N
�D⇤� ! D0(f)⇡�
s�
⇪
Combination with previous CP violation measurements in charm: ‣ Indirect CP asymmetries with prompt D*+
→ D0 π+: AΓ(K+K−) and AΓ(π+π−) [PRL 112, 041801 (2014)]
‣ Indirect CP asymmetries with semileptonic (SL) B − → D0 𝜇−𝜈 [JHEP 04 (2015) 043]
‣ Direct CP asymmetries with semileptonic (SL) B − → D0 𝜇−𝜈 [JHEP 07 (2014) 041]
Consistent with no CP violation in the charm sector!
Simon Akar 12Blois 16' - CP violation in B and charm decays @ LHCb
LHCb
no CPV
AΓ SL K−Κ+
and π−π+
AΓ prompt K−Κ+
AΓ prompt π−π+
∆ACP
SL
∆ACP
pro
mp
t
10
5
0
-5
-10-10 -5 0 -5 10
∆aCP dir
aCP ind
×10-3
×10-3
Search for CP violation in D0 → K+K− and D0 → π+π−arXiv:1602.03160 [hep-ex]
3
Constraints on the CKM angle γ
‣ The CKM angle γ can be directly measured at tree level, without pollution from penguin amplitudes
‣ To probe NP, one can compare direct and indirect measurements of γ:
‣ The “ultimate” γ-from tree-decays precision will be reached through many individual measurements, with very different sensitivities (due to different b→u to b→c amplitudes ratio)
Motivations
Simon Akar 14Blois 16' - CP violation in B and charm decays @ LHCb
Combination of direct measurement from BaBar, Belle and LHCb (CKM2014)
Indirect determination from global fit to CKM parameters (excluding γ)
γ
α
α
dm∆ Kεsm∆ & dm∆
ubV
βsin 2(excl. at CL > 0.95)
< 0βsol. w/ cos 2
α
βγ
ρ-0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
η0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
excl
uded
are
a ha
s C
L >
0.95
EPS 15
CKMf i t t e r
γ
‣ Use tree decays of B ± → DK± which lead to the same final state with interference between D0
— D0̅
decays to the same final state
‣ Combination of results from several modes using different experimental methods :
- GLW: CP-even final states
[PLB 265 (1991) 172] [PLB 253 (1991) 483]
- ADS: CF or DCS final states [PRL 78, 3257 (1997)] [PRD 63 (2001) 036005]
- GGSZ: 3 body final states [PRD 68 (2003) 054018]
Ingredients for γ measurements
Simon Akar 15Blois 16' - CP violation in B and charm decays @ LHCb
Cabibbo favored (CF) Doubly Cabibbo suppressed (DCS)
external measurements
⇪
Inputs for γ combination
Simon Akar 16Blois 16' - CP violation in B and charm decays @ LHCb
B decay D decay TypeRL Ref.
LHCb
Inputs
B+ ! DK+ D ! hh GLW/ADS 3fb�1 [arXiv:1603.08993] ?B+ ! DK+ D ! h⇡⇡⇡ GLW/ADS 3fb�1 [arXiv:1603.08993] ?B+ ! DK+ D ! hh⇡0 GLW/ADS 3fb�1 [arXiv:1504.05442] ?B+ ! DK+ D ! K0
Shh GGSZ 3fb�1 [arXiv:1405.2797]B+ ! DK+ D ! K0
SK⇡ GLS 3fb�1 [arXiv:1402.2982]B0 ! D0K?0 D ! K⇡ ADS 3fb�1 [arXiv:1407.3186]B+ ! DK+⇡⇡ D ! hh GLW/ADS 3fb�1 [arXiv:1505.07044] ?B0
s ! D⌥s K
± D+s ! hhh TD 1fb�1 [arXiv:1407.6127]
B0 ! D0K+⇡� D ! hh Dalitz 3fb�1 [arXiv:1602.03455] ?B0 ! D0K?0 D ! K0
S⇡⇡ GGSZ 3fb�1 [arXiv:1605.01082] ?
Decay Parameters Source Ref.
Auxilliary
Inputs
Charm mixing HFAG - [arXiv:1412.7515]D ! K⇡⇡⇡ (�D, D, rD) CLEO+LHCb - [arXiv:1602.07430] ?D ! ⇡⇡⇡⇡ (F+) CLEO - [arXiv:1504.05878] ?D ! K⇡⇡0 (�D, D, rD) CLEO+LHCb - [arXiv:1602.07430] ?D ! hh⇡0 (F+) CLEO - [arXiv:1504.05878] ?D ! K0
SK⇡ (�D, D) CLEO - [arXiv:1203.3804]D ! K0
SK⇡ (rD) CLEO - [arXiv:1203.3804]D ! K0
SK⇡ (rD) LHCb - [arXiv:1509.06628]B0 ! D0K?0 (B , RB , �B) LHCb - [arXiv:1602.03455] ?B0
s ! J/ h+h� (�s) LHCb - [arXiv:1411.3104]
Combination: [LHCb-CONF-2016-001]
? new or updated since last combination
Inputs for γ combination
Simon Akar 17Blois 16' - CP violation in B and charm decays @ LHCb
B decay D decay TypeRL Ref.
LHCb
Inputs
B+ ! DK+ D ! hh GLW/ADS 3fb�1 [arXiv:1603.08993] ?B+ ! DK+ D ! h⇡⇡⇡ GLW/ADS 3fb�1 [arXiv:1603.08993] ?B+ ! DK+ D ! hh⇡0 GLW/ADS 3fb�1 [arXiv:1504.05442] ?B+ ! DK+ D ! K0
Shh GGSZ 3fb�1 [arXiv:1405.2797]B+ ! DK+ D ! K0
SK⇡ GLS 3fb�1 [arXiv:1402.2982]B0 ! D0K?0 D ! K⇡ ADS 3fb�1 [arXiv:1407.3186]B+ ! DK+⇡⇡ D ! hh GLW/ADS 3fb�1 [arXiv:1505.07044] ?B0
s ! D⌥s K
± D+s ! hhh TD 1fb�1 [arXiv:1407.6127]
B0 ! D0K+⇡� D ! hh Dalitz 3fb�1 [arXiv:1602.03455] ?B0 ! D0K?0 D ! K0
S⇡⇡ GGSZ 3fb�1 [arXiv:1605.01082] ?
Decay Parameters Source Ref.
Auxilliary
Inputs
Charm mixing HFAG - [arXiv:1412.7515]D ! K⇡⇡⇡ (�D, D, rD) CLEO+LHCb - [arXiv:1602.07430] ?D ! ⇡⇡⇡⇡ (F+) CLEO - [arXiv:1504.05878] ?D ! K⇡⇡0 (�D, D, rD) CLEO+LHCb - [arXiv:1602.07430] ?D ! hh⇡0 (F+) CLEO - [arXiv:1504.05878] ?D ! K0
SK⇡ (�D, D) CLEO - [arXiv:1203.3804]D ! K0
SK⇡ (rD) CLEO - [arXiv:1203.3804]D ! K0
SK⇡ (rD) LHCb - [arXiv:1509.06628]B0 ! D0K?0 (B , RB , �B) LHCb - [arXiv:1602.03455] ?B0
s ! J/ h+h� (�s) LHCb - [arXiv:1411.3104]
Combination: [LHCb-CONF-2016-001]
? new or updated since last combination
3
Constraints on the CKM angle γ
‣ GLW / ADS B ± → Dh± (2-4 body)
arXiv:1603.08993 [hep-ex] Full Run1 data: 3 fb-1NEW!
‣ Measure charge asymmetries (A) and partial width ratios (R)
with h = (K,π)
‣ GLW: D0 → K+K− / π+π− / π+π−π+π−
Simon Akar 19Blois 16' - CP violation in B and charm decays @ LHCb
GLW / ADS B ± → Dh± (2-4 body)arXiv:1603.08993 [hep-ex]
A =� (B� ! fDh�)� �
�B+ ! f̄Dh+
�
� (B� ! fDh�) + ��B+ ! f̄Dh+
�
R =� (B� ! fDh�) + �
�B+ ! f̄Dh+
�
� (B� ! f 0Dh�) + �
�B+ ! f̄ 0
Dh+�A =
� (B� ! fDh�)� ��B+ ! f̄Dh+
�
� (B� ! fDh�) + ��B+ ! f̄Dh+
�
R =� (B� ! fDh�)� �
�B+ ! f̄Dh+
�
� (B� ! f 0Dh�) + �
�B+ ! f̄ 0
Dh+�
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
First time
Exam
ples
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
AADS Averages
HFA
GM
orio
nd 2
016
HFA
GM
orio
nd 2
016
HFA
GM
orio
nd 2
016
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
D_K
π K
D_K
ππ0 K
D_K
3π K
D*_
Dπ0 _K
π K
D*_
Dγ_
Kπ K
D_K
π K*
D_K
π Kπ
π
-2 -1 0 1
BaBarPRD 82 (2010) 072006
-0.86 ± 0.47 +-00
.
.11
26
BellePRL 106 (2011) 231803
-0.39 +-00
.
.22
68 +-0
0..00
43
CDFPRD 84 (2011) 091504
-0.82 ± 0.44 ± 0.09
LHCbarXiv:1603.08993
-0.40 ± 0.06 ± 0.01
AverageHFAG
-0.41 ± 0.06
BellePRD 88 (2013) 091104(R)
0.41 ± 0.30 ± 0.05
LHCbPR D91 (2015) 112014
-0.20 ± 0.27 ± 0.03
AverageHFAG
0.07 ± 0.20
LHCbarXiv:1603.08993
-0.31 ± 0.10 ± 0.04
AverageHFAG
-0.31 ± 0.11
BaBarPRD 82 (2010) 072006
0.77 ± 0.35 ± 0.12
BelleLP 2011 preliminary
0.40 +-10
.
.17
00 +-0
0..21
00
AverageHFAG
0.72 ± 0.34
BaBarPRD 82 (2010) 072006
0.36 ± 0.94 +-00
.
.24
51
BelleLP 2011 preliminary
-0.51 +-00
.
.32
39 ± 0.08
AverageHFAG
-0.43 ± 0.31
BaBarPRD 80 (2009) 092001
-0.34 ± 0.43 ± 0.16
AverageHFAG
-0.34 ± 0.46
LHCbPRD 92 (2015) 112005
-0.32 +-00
.
.23
74
AverageHFAG
-0.32 +-00
.
.23
74
H F A GH F A GMoriond 2016PRELIMINARY
AADS Averages
HFA
GM
orio
nd 2
016
HFA
GM
orio
nd 2
016
HFA
GM
orio
nd 2
016
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
D_K
π K
D_K
ππ0 K
D_K
3π K
D*_
Dπ0 _K
π K
D*_
Dγ_
Kπ K
D_K
π K*
D_K
π Kπ
π
-2 -1 0 1
BaBarPRD 82 (2010) 072006
-0.86 ± 0.47 +-00
.
.11
26
BellePRL 106 (2011) 231803
-0.39 +-00
.
.22
68 +-0
0..00
43
CDFPRD 84 (2011) 091504
-0.82 ± 0.44 ± 0.09
LHCbarXiv:1603.08993
-0.40 ± 0.06 ± 0.01
AverageHFAG
-0.41 ± 0.06
BellePRD 88 (2013) 091104(R)
0.41 ± 0.30 ± 0.05
LHCbPR D91 (2015) 112014
-0.20 ± 0.27 ± 0.03
AverageHFAG
0.07 ± 0.20
LHCbarXiv:1603.08993
-0.31 ± 0.10 ± 0.04
AverageHFAG
-0.31 ± 0.11
BaBarPRD 82 (2010) 072006
0.77 ± 0.35 ± 0.12
BelleLP 2011 preliminary
0.40 +-10
.
.17
00 +-0
0..21
00
AverageHFAG
0.72 ± 0.34
BaBarPRD 82 (2010) 072006
0.36 ± 0.94 +-00
.
.24
51
BelleLP 2011 preliminary
-0.51 +-00
.
.32
39 ± 0.08
AverageHFAG
-0.43 ± 0.31
BaBarPRD 80 (2009) 092001
-0.34 ± 0.43 ± 0.16
AverageHFAG
-0.34 ± 0.46
LHCbPRD 92 (2015) 112005
-0.32 +-00
.
.23
74
AverageHFAG
-0.32 +-00
.
.23
74
H F A GH F A GMoriond 2016PRELIMINARY
AADS Averages
HFA
GM
orio
nd 2
016
HFA
GM
orio
nd 2
016
HFA
GM
orio
nd 2
016
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
HFA
G
Mor
iond
201
6
D_K
π K
D_K
ππ0 K
D_K
3π K
D*_
Dπ0 _K
π K
D*_
Dγ_
Kπ K
D_K
π K*
D_K
π Kπ
π
-2 -1 0 1
BaBarPRD 82 (2010) 072006
-0.86 ± 0.47 +-00
.
.11
26
BellePRL 106 (2011) 231803
-0.39 +-00
.
.22
68 +-0
0..00
43
CDFPRD 84 (2011) 091504
-0.82 ± 0.44 ± 0.09
LHCbarXiv:1603.08993
-0.40 ± 0.06 ± 0.01
AverageHFAG
-0.41 ± 0.06
BellePRD 88 (2013) 091104(R)
0.41 ± 0.30 ± 0.05
LHCbPR D91 (2015) 112014
-0.20 ± 0.27 ± 0.03
AverageHFAG
0.07 ± 0.20
LHCbarXiv:1603.08993
-0.31 ± 0.10 ± 0.04
AverageHFAG
-0.31 ± 0.11
BaBarPRD 82 (2010) 072006
0.77 ± 0.35 ± 0.12
BelleLP 2011 preliminary
0.40 +-10
.
.17
00 +-0
0..21
00
AverageHFAG
0.72 ± 0.34
BaBarPRD 82 (2010) 072006
0.36 ± 0.94 +-00
.
.24
51
BelleLP 2011 preliminary
-0.51 +-00
.
.32
39 ± 0.08
AverageHFAG
-0.43 ± 0.31
BaBarPRD 80 (2009) 092001
-0.34 ± 0.43 ± 0.16
AverageHFAG
-0.34 ± 0.46
LHCbPRD 92 (2015) 112005
-0.32 +-00
.
.23
74
AverageHFAG
-0.32 +-00
.
.23
74
H F A GH F A GMoriond 2016PRELIMINARY
‣ ADS: D0 → K±π∓ / K±π∓ π+π−
‣ GLW/ADS: - In total 21 CP observables entering
in the γ combination
- Good sensitivity to the ADS modes compared to other experiments
Simon Akar 20Blois 16' - CP violation in B and charm decays @ LHCb
First observation of CP violation in single B → Dh decay mode
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
−KD]+K−π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
+KD]−K+π[→+B
LHCb
5100 5200 5300 5400 5500
200
400
−πD]+K−π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
+πD]−K+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
150
−KD]−π+π−π+π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
0
+KD]−π+π−π+π[→+B
LHCb
5100 5200 5300 5400 5500
500
1000
1500
2000
−πD]−π+π−π+π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
0
0
+πD]−π+π−π+π[→+B
LHCb
Exam
ple
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
−KD]+K−π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
+KD]−K+π[→+B
LHCb
5100 5200 5300 5400 5500
200
400
−πD]+K−π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
+πD]−K+π[→+B
LHCb
5100 5200 5300 5400 5500
) 2 cEv
ents
/ ( 1
0 M
eV/
50
100
−KD]+K−π[→−B
LHCb
5100 5200 5300 5400 5500
0
0
+KD]−K+π[→+B
LHCb
5100 5200 5300 5400 5500
200
400
−πD]+K−π[→−B
LHCb
] 2c) [MeV/±Dh(m5100 5200 5300 5400 5500
0
0
+πD]−K+π[→+B
LHCb
GLW / ADS B ± → Dh± (2-4 body)arXiv:1603.08993 [hep-ex]
A ≠ 0 @ 8𝝈
3
Constraints on the CKM angle γ
‣ GLW / ADS B ± → Dh± (2-4 body)
arXiv:1603.08993 [hep-ex] Full Run1 data: 3 fb-1
‣ GGSZ analysis of B 0 → DK*0 decays
arXiv:1605.01082 [hep-ex] Full Run1 data: 3 fb-1
NEW!
Simon Akar 22Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays arXiv:1605.01082 [hep-ex]
‣ Lower rate than B ± → DK±, but larger interference effects (rB0 ~ 3 rB+)
‣ GGSZ: D0 → KS0π+π−
- Multi-body D decays ⇒ charge asymmetry varies accros Dalitz plane - Two experimental methods:
model dependent (MD) [arXiv:1605.01082] ; model independent (MI) [arXiv:1604.01525] (only MD γ in combination)
‣ Model-dependent analysis: - First perform a fit to the B 0 mass
- Making use of BaBar’s amplitude model [arXiv:1005.1096] to fit Dalitz plane for events within signal region
- Signal yield (89 ± 11) Twice more events than previous B-factory measurement
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
)2 (GeV+2m
1 2 3)2
(GeV
−2m
0.5
1
1.5
2
2.5
3
)2 (GeV+2m
1 2 3
)2 (G
eV−2
m
0.5
1
1.5
2
2.5
3
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
Simon Akar 23Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays arXiv:1605.01082 [hep-ex]
‣ Fit Dalitz plane to extract CP observables (x±,y±)
‣ Results (MD): - CP observables compatible with MI results - Leads to a unique solution for γ:
±x-1 0 1
±y
-1
0
10B
0B
LHCb
]°[γ
CL
−1
0
0.2
0.4
0.6
0.8
1
50 100 150
22−+2180
68.3%
95.5%
LHCb
B0 B0
3
Constraints on the CKM angle γ
‣ LHCb γ combination LHCb-CONF-2016-001
NEW!
Simon Akar 25Blois 16' - CP violation in B and charm decays @ LHCb
LHCb γ combination LHCb-CONF-2016-001
‣ Complementarity of different methods: ADS/GLW, quasi-ADS/GLW, GGSZ
]° [γ
DK
Br
0 50 100 1500
0.05
0.1
0.15
0.2
π/h30πhh→ D+K0D→+B hhSK→ D+K0D→+B ππ/KK/πK→ D+K0D→+B modesuAll BCombination
LHCbPreliminary
contours hold 68%, 95% CL
]° [γ0
DK
*Br
0 50 100 1500
0.2
0.4
0.6
0.8
ππ/KK/πK→ D0K*0D→0B KKSK→ D0K*0D→0B modesdAll BCombination
LHCbPreliminary
contours hold 68%, 95% CL
0π/hh'π h3→, D+ DK→+B
hhSK→, D+ DK→+B
ππ/πKK/K→, D+ DK→+B
modes+All B
Full LHCb Combination
ππ/πKK/K→, D*0 DK→0B
ππSK→, D*0 DK→0B
modes0All B
Full LHCb Combination
B 0 → D 0K*0 modesB + → D 0K+ modes
‣ Most precise measurement from a single experiment:
‣ Consistent with B-factories:
and indirect determination:
Simon Akar 26Blois 16' - CP violation in B and charm decays @ LHCb
LHCb γ combination LHCb-CONF-2016-001
� = (70.9+7.1�8.5)
�
]° [γ1-
CL
0
0.2
0.4
0.6
0.8
1
0 50 100 150
68.3%
95.5%
LHCbPreliminary
GGSZGLW/ADSOthersCombination
GGSZGLW/ADSOthersCombination� = (66.85+0.94
�3.44)�
4
CP asymmetry in B𝒔
0 —B̅
𝒔0 mixing
Preliminary results Full Run1 data: 3 fb-1NEW!
Simon Akar 28Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
‣ As in charm sector, any significant CP violation in B𝒔0 —B̅𝒔
0 mixing
would be an indication of NP:
[arXiv:1511.09466]assl =P(B0
s ! B0s )� P(B0
s ! B0s)
P(B0s ! B0
s ) + P(B0s ! B0
s)
SM⇠ O(10�5)
20141fb-1
3fb-1
Simon Akar 29Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
‣ Update of asls with 3 fb-1:
- Inclusive B𝒔0 → D𝒔
− 𝝁+𝝂𝝁X decays
- Time integrated analysis: production asymmetry cancels thanks to fast B𝒔0 oscillations
(details in back-up )
- Measurement performed separately in 3 regions of Dalitz (fbkg dependent)
- Abkg mainly from production asymmetries
[New J.Phys. 15 (2013) 053021]
⇪
Simon Akar 30Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
‣ Results: (preliminary)
assl = (0.45± 0.26(stat)± 0.20(syst))%
5
Summary and Conclusions
Summary and conclusion
Simon Akar 32
• CKM matrix is incredibly successful description of the quark sector in the SM, and the measurements of CKM elements are becoming increasingly precise ‣ Most precise measurement of γ from a single experiment:
‣ No evidence for CP violation in charm
‣ CP violation in B𝒔0 —B ̅
𝒔0 mixing consistent with SM prediction
• Expect several new results with improved sensitivity in the future ‣ Current results mostly statistically dominated ‣ Improved trigger scheme for Run2 and LHCb Upgrade leads to
billion of charm events and significant increase of hadronic B decays efficiencies!
Blois 16' - CP violation in B and charm decays @ LHCb
� = (70.9+7.1�8.5)
�
‣ Experiment apparatus and analysis techniques
‣ Mixing and CP violation in charm: - First observation of D0
—D̅0 oscillations in D0 → K+π−π+π−
- Search for CP violation in D0 → K+K− and D0 → π+π−
‣ Constraints on the CKM angle γ: - GLW / ADS B ± → Dh± (2-4 body) - GGSZ analysis of B 0 → DK*0 decays - LHCb γ combination
‣ CP asymmetry in B𝒔0 —B�̅�
0 mixing
Additional material
Simon Akar 33Blois 16' - CP violation in B and charm decays @ LHCb
⇪
⇪
⇪
⇪
⇪
⇪
⇪
Simon Akar 34Blois 16' - CP violation in B and charm decays @ LHCb
The LHCb experiment
Vertex detectorreconstruct vertices decay time resolution: 46 fs IP reconstruction: 20 𝜇m
~12 MHz visibles
interactions (2012)
Collisions@ 40 MHz
RICH detectorsK/π/p separation
Calorimetersenergy measurement particle identification
Muon system
Tracking systemmomentum resolution ∆p/p = 0.4% — 0.6%
Dipole magnet4 Tm normal conducting regular polarity switches
• Forward General-Purpose Detector at the LHC • ~30 % of heavy quark production cross-section with just 4% of solid angle
⇧
Simon Akar 35Blois 16' - CP violation in B and charm decays @ LHCb
Flavor tagging
⇧
‣ Fitted parameters (uncertainties include all systematics)
Simon Akar 36Blois 16' - CP violation in B and charm decays @ LHCb
First observation of D0 — D̅ 0
oscillations in D0 → K+π−π+π−arXiv:1602.07224 [hep-ex]
⇧⇪
Measured asymmetry:
‣ AD(K+K−) and AD(π+π−) cancels due to self-conjugated final states.
‣ AD(π+s) and AP(D*+
) independent of the final state f in any given kinematic region, and thus cancel in the difference: ‣ Residual differences due to different kinematics between K+K− and π+π− cancelled thanks to
reweighing K+K− kinematic to match those of π+π−
Search for CP violation in D0 → K+K− and D0 → π+π−
Simon Akar 37Blois 16' - CP violation in B and charm decays @ LHCb
arXiv:1602.03160 [hep-ex]
Araw(f) =N
�D⇤+ ! D0(f)⇡+
s
��N
�D⇤� ! D0(f)⇡�
s
�
N�D⇤+ ! D0(f)⇡+
s�+N
�D⇤� ! D0(f)⇡�
s�
Araw(f) =�ACP (f) +AD(f) +AD(⇡+
s ) +AP (D⇤+)
�+O(10�6)
�ACP = Araw(K+K�)�Araw(⇡
+⇡�)
�ACP = ACP (K+K�)�ACP (⇡
+⇡�)
⇧⇪
Principles of the methods: 2 body final states
Simon Akar 38Blois 16' - CP violation in B and charm decays @ LHCb
GLW / ADS B ± → Dh± (2-4 body)arXiv:1603.08993 [hep-ex]
⇧⇪
Principles of the methods: 4 body final states
Simon Akar 39Blois 16' - CP violation in B and charm decays @ LHCb
GLW / ADS B ± → Dh± (2-4 body)arXiv:1603.08993 [hep-ex]
⇧⇪
Results summary:
‣ ADS: D0 → K±π∓ / K±π∓ π+π−
‣ GLW: D0 → K+K− / π+π− / π+π−π+π−
Simon Akar 40Blois 16' - CP violation in B and charm decays @ LHCb
GLW / ADS B ± → Dh± (2-4 body)arXiv:1603.08993 [hep-ex]
⇧⇪
Simon Akar 41Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays
Principle of the methods:
‣ Model-dependent method: [arXiv:1605.01082] - Making use of an amplitude model providing the
strong phase 𝞭D
‣ Model-independent method: [arXiv:1604.01525] - Direct access to 𝞭D from a binned Dalitz plot analysis
simultaneously with D0 → KS0K+K−
⇧⇪
Simon Akar 42Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays arXiv:1605.01082 [hep-ex]
Model-dependent method: ‣ Decay rate at a point of the Dalitz plane:
- the coherence factor 𝜅 is obtained from an amplitude analysis of B 0 → DK+π− [arXiv:1602.03455]
⇧⇪
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
)2 (GeV+2m
1 2 3
)2 (G
eV−2
m
0.5
1
1.5
2
2.5
3
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
B0
)2 (GeV+2m
1 2 3)2
(GeV
−2m
0.5
1
1.5
2
2.5
3
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
B0
Simon Akar 43Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays arXiv:1605.01082 [hep-ex]
Model-dependent method: ‣ Decay rate at a point of the Dalitz plane:
- CP observables:
⇧⇪
)2 (GeV−2m
1 2
]2Ca
ndid
ates
/ [0
.13
GeV
0
2
4
6
8
10
12
)2 (GeV02m
0.5 1 1.5
]2Ca
ndid
ates
/ [0
.09
GeV
02468
10121416
)2 (GeV+2m
1 2
]2Ca
ndid
ates
/ [0
.13
GeV
02468
1012141618
)2 (GeV−2m
1 2
]2Ca
ndid
ates
/ [0
.13
GeV
02468
1012141618
)2 (GeV02m
0.5 1 1.5
]2Ca
ndid
ates
/ [0
.09
GeV
0
2
4
6
8
10
12
)2 (GeV+2m
1 2
]2Ca
ndid
ates
/ [0
.13
GeV
0
2
4
6
8
10
12)2 (GeV+
2m1 2 3
)2 (G
eV−2
m
0.5
1
1.5
2
2.5
3
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
B0
)2 (GeV+2m
1 2 3
)2 (G
eV−2
m
0.5
1
1.5
2
2.5
3
m(DK*) (MeV)5000 5200 5400 5600 5800
Cand
idat
es /
[18
MeV
]
0
20
40
60
80
100 LHCb 0 DK*→0B
0*K D→0sB
Combinatorial0 D*K*→0B
0*K D*→0sB
0ρ D→0B
B0
Simon Akar 44Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays arXiv:1604.01525 [hep-ex]
Model-independent method: ‣ Decay rate in a bin of the Dalitz plane:
- the parameters ci and si taken from CLEO measurements using quantum-correlated 𝜓(3770) → DD ̅decays [PRD 82 (2010) 112006]
⇧⇪
Simon Akar 45Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays arXiv:1604.01525 [hep-ex]
Model-independent method: ‣ Fit simultaneously D0 → KS
0π+π− and D0 → KS0K+K−
⇧⇪
Simon Akar 46Blois 16' - CP violation in B and charm decays @ LHCb
GGSZ analysis of B 0 → DK*0 decays
MI and MD results:
⇧⇪
±x1− 0 1
±y
1−
0
1
0B
0BLHCb
±x-1 0 1
±y
-1
0
10B
0B
LHCbMI MD
Simon Akar 47Blois 16' - CP violation in B and charm decays @ LHCb
LHCb γ combination LHCb-CONF-2016-001
‣ Auxiliary inputs:
⇧⇪
Simon Akar 48Blois 16' - CP violation in B and charm decays @ LHCb
LHCb γ combination LHCb-CONF-2016-001
‣ Auxiliary input values:
⇧⇪
Simon Akar 49Blois 16' - CP violation in B and charm decays @ LHCb
LHCb γ combination LHCb-CONF-2016-001
‣ Complementarity of different methods: ADS/GLW, quasi-ADS/GLW, GGSZ
⇧⇪
Simon Akar 50Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Detection asymmetries: - PID
⇧⇪
]c [GeV/Tp
0 5 10
) [%
]±
K(PI
DA
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Magnet upMagnet down
LHCb
]c [GeV/Tp
0 5 10
) [%
]±
K(PI
DA
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Magnet upMagnet down
LHCbpreliminary preliminary
Simon Akar 51Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Detection asymmetries: - Tracking
⇧⇪
]c [GeV/p20 40 60 80 100
) [%
]± π (
track
A
2−
1−
0
1
2
3
4
LHCb Magnet up
Magnet downpreliminary
Simon Akar 52Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Detection asymmetries: - Trigger
⇧⇪
]c [GeV/Tp
0 5 10 15
) [%
]± µ(
det
A
-6
-4
-2
0
2
4
6Magnet upMagnet downAverage
LHCb 2012
]c [GeV/Tp
0 5 10 15) [
%]
± µ(de
tA
-6
-4
-2
0
2
4
6Magnet upMagnet downAverage
LHCb 2011preliminary preliminary
Simon Akar 53Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Results in categories:
⇧⇪
,2012,Upπφ ,2012,Down
πφ ,2011,Upπφ ,2011,Down
πφ ,2012,UpK*K ,2012,Down
K*K ,2011,UpK*K ,2011,Down
K*K ,2012,UpNR ,2012,Down
NR ,2011,UpNR ,2011,Down
NR
)-2
10
× (s sla
-4-3-2-1012345
LHCbpreliminary
Simon Akar 54Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Mass fit projections:
⇧⇪
)_PhiPi (MeV)+π+K-(KinvM1800 1850 1900 1950 2000
)2 c /
(2.5
MeV
/3
10
×Ca
ndid
ates
50100150
)_KStarK (MeV)+π+K-(KinvM1800 1850 1900 1950 2000
204060
]2c) [MeV/±π−K+K(m1800 1850 1900 1950 2000
20
40
±sD±D
Comb.
LHCbπφ
K*K
NR
]4c/2) [GeV
±
K±K(2m1 2 3
]4 c/2) [
GeV
±π±
K(2m
0.5
1
1.5
2
2.5
1
10
210
310
πφ ←
K*K
NR
±π
±
K±K → ±sDLHCbpreliminary
preliminary
Simon Akar 55Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Peaking backgrounds:
⇧⇪
Simon Akar 56Blois 16' - CP violation in B and charm decays @ LHCb
CP asymmetry in B𝒔0 —B̅
𝒔0 mixing
preliminary results
Systematics:
⇧⇪
