measurement of the ckm angle charm mixing and … of the ckm angle g charm mixing and cp violation...
TRANSCRIPT
![Page 1: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/1.jpg)
Measurement of the CKM angle g charm mixing and CP violation at LHCb
Outline: LHCb detector & data taking Measurements of CKM angle g Determination of D0-D0 mixing and CP violation parameters Summary
Pavel Krokovnyon behalf of the LHCb Collaboration
Budker INP & Novosibirsk University
28 May HQL 2018 Yamagata
![Page 2: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/2.jpg)
LHCb Experiment
2
![Page 3: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/3.jpg)
LHCb dataset Good tracking performance: momentum uncertainty 0.5-1.0%
Excellent vertexing: IP resolution (15+29/pT) mm Acceptance: 2 < η < 5
2.0 fb-1 @ 8 TeV
1.0 fb-1 @ 7 TeV
3Int. J. Mod. Phys. A30 (2015) 1530022
![Page 4: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/4.jpg)
LHCb detector asymmetries
Measure raw asymmetries
4Int. J. Mod. Phys. A30 (2015) 1530022
N (x)−N ( x)N (x )+N (x )
CP asymmetry, detector asymmetry,production asymmetry
sum of
Sources of detector asymmetry:● Magnet sweeps opposite-charged particles
in different directions (detector not perfectly
symmetric)
● Different cross section of nuclear
interactions for particles and antiparticles
Solutions:● Regularly reverse polarity. Fiducial cuts to
remove most asymmetric regions
● Irreducible: measure in control
channels
![Page 5: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/5.jpg)
Unitarity Triangleg is the least well constrained angle of the unitarity triangleNon-trivial triangle - CP-violationNot a triangle - Beyond SM Physics
5
![Page 6: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/6.jpg)
How to measure gTwo amplitudes b→cW(us) [B-→D0K-] and b→uW(cs) [B-→D0K-] give same final state when both D and D decay to a common final state.No penguin contribution theoretically clean.⇒
6
● Amplitude ratios: ● Strong phases:
rB, r
D
dB, d
D
![Page 7: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/7.jpg)
Experimental methods● GLW (Gronau, London, Wyler) [1991]: D→K+K-, p+p-
● ADS (Atwood, Dunietz, Soni) [1997,2001]: D→K+p-
● GGSZ (Giri, Grossman, Soer, Zupan) [2003]: D→K0Sp+p-
Dalitz plot DKS
0p+p- ds(m+
2, m-2) ~ |A|2dm
+2 dm
-2, m
±2 = m2(K
S0p±),
D0 amplitude: AD(m
+2, m
-2), D0 amplitude: A
D(m
-2, m
+2)
Amplitude of DKS
0p+p- from B+DK+ :
A
D(m
+2,m
-2) + r
BeidB + ig A
D(m
-2,m
+2)
7
ΑCP=Γ(B−→DCP K−
)−Γ(B+→DCP K+
)
Γ(B−→DCP K−
)+Γ(B+→DCP K+
)=
2 r Bsin (δ B+δ D)sin γ
1+rB2+2 r B cos(δ B+δ D)cos γ
ΑCP=Γ(B−→[K+
p - ]K− )−Γ(B+→[K - p+ ]K + )
Γ(B−→[K +p - ]K−
)+Γ(B+→[K - p+]K+
)=
2 r Br D sin(δB+δD)sin γ
r B2+r D
2+2 r Br D cos (δB+δD)cos γ
![Page 8: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/8.jpg)
ADS: B±→D(*)K± and B±→D(*)π±
8Physics Letters B 777 (2018) 16-30
![Page 9: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/9.jpg)
GLW: B±→D(*)K± and B±→D(*)π±
9
Physics Letters B 777 (2018) 16-30
Dataset:1.0 fb-1 @ √s=7 TeV2.0 fb-1 @ √s=8 TeV2.0 fb-1 @ √s=13TeV
RCP
= 0.989 ± 0.013 ± 0.010
ACP
=+0.124 ±0.012 ±0.002
A = ACP
+Adet
+Aprod
![Page 10: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/10.jpg)
Results: B±→D(*)K± and B±→D(*)π±
10
Physics Letters B 777 (2018) 16-30
Dataset:1.0 fb-1 @ √s=7 TeV2.0 fb-1 @ √s=8 TeV2.0 fb-1 @ √s=13TeV
![Page 11: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/11.jpg)
B±→DK*±
11JHEP 11 (2017) 156
Dataset:1.0 fb-1 @ √s=7 TeV2.0 fb-1 @ √s=8 TeV1.8 fb-1 @ √s=13TeV
![Page 12: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/12.jpg)
ADS: B±→DK*±
12
JHEP 11 (2017) 156
![Page 13: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/13.jpg)
GLW: B±→DK*±
13
JHEP 11 (2017) 156
![Page 14: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/14.jpg)
Results: B±→DK*±
14
JHEP 11 (2017) 156
RCP+
= 1.18 ± 0.08 ± 0.02
ACP+
= +0.08 ± 0.06 ± 0.01
RkpADS
= 0.0011 ± 0.004 ± 0.001
AkpADS
= -0.81 ± 0.17 ± 0.04
RkpppADS
= 0.0011 ± 0.005 ± 0.003
AkpppADS
= -0.45 ± 0.21 ± 0.14
![Page 15: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/15.jpg)
GGSZ method
15LHCb paper 2018-017
Dataset:1.0 fb-1 @ √s=7 TeV2.0 fb-1 @ √s=8 TeV2.0 fb-1 @ √s=13TeV
x± ≡ r
B cos(d
B ± g) and y
± = r
B sin(d
B ± g)
![Page 16: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/16.jpg)
GGSZ results
16
LHCb paper 2018-017PRELIMINARY
PRELIMINARY
PRELIMINARY
![Page 17: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/17.jpg)
Measurement of CP violation in B0→D∓p±
17arXiv:1805.03448
Dataset:1.0 fb-1 @ √s=7 TeV2.0 fb-1 @ √s=8 TeV
![Page 18: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/18.jpg)
Measurement of CP violation in B0→D∓p±
18
arXiv:1805.03448
![Page 19: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/19.jpg)
Measurement of CP violation in B0→D∓p±
19
arXiv:1805.03448
![Page 20: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/20.jpg)
g combination
20LHCb CONF 2018-002
![Page 21: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/21.jpg)
g combination
21LHCb CONF 2018-002
Bs0→D
s∓K± time-dep
B0→DK*0
B0→DK+p-
B0→D∓p± time-dep
B+→DK+
B+→D*K+
B+→DK*+
B+→DK+p+p-
![Page 22: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/22.jpg)
D0-D0 mixing and CP violation in D0→K+π−
22
Right-sign (RS) D0→K-π+ is dominated by CF decay
Wrong-sign (WS) D0→K+π-
has two sources:
Mixing amplitude is time-dependent
Ratio R(t) = ΓWS
(t)/ΓRS
(t) depends on x and y:
R( t)=RD+√RD y '(
tτ )+
x' 2+ y ' 2
4(
tτ )
2
( x 'y ')=(
cosd sin d−sin d cos d)(
xy )
R±(t)=RD
±+√RD
± y '±(
tτ )+
x '±2+ y '±2
4(
tτ )
2 ICPV: x’+ ≠ x’−
and/or y’+ ≠ y’−
DCPV: RD
+ ≠ RD
-
![Page 23: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/23.jpg)
D0-D0 mixing and CP violation by D0→K+π−
23Phys Rev D97, 031101 (2018)
177 106
RS events 0.72 106
WS events
Dataset:1.0 fb-1 @ √s=7 TeV2.0 fb-1 @ √s=8 TeV2.0 fb-1 @ √s=13TeV
![Page 24: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/24.jpg)
D0-D0 mixing and CP violation by D0→K+π−
24Phys Rev D97, 031101 (2018)
![Page 25: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/25.jpg)
D0-D0 mixing and CP violation by D0→K+π−
25Phys Rev D97, 031101 (2018)
RD = 3.454 ± 0.028 ± 0.014
y` = 5.28 ± 0.45 ± 0.27x`2 = 0.039 ± 0.023 ± 0.014
RD = 3.454 ± 0.028 ± 0.014
y`+ = 5.01 ± 0.48 ± 0.29(x`+)2 = 0.061 ± 0.026 ± 0.016y`- = 5.54 ± 0.48 ± 0.29(x`-)2 = 0.016 ± 0.026 ± 0.016
RD
+ = 3.454 ± 0.040 ± 0.020y`+ = 5.01 ± 0.64 ± 0.38(x`+)2 = 0.061 ± 0.032 ± 0.019R
D- = 3.454 ± 0.040 ± 0.020
y`- = 5.54 ± 0.64 ± 0.38(x`-)2 = 0.016 ± 0.033 ± 0.020
AD= (−0.1 ± 9.1)×10−3
![Page 26: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/26.jpg)
26
Conclusion LHCb continue efforts to measure CKM angle g.
Combined result is still limited by statistics.
Further progress expected after LHCb upgrade. Most precisest
GGSZ method requires preciest measurement of strong phase
difference δD on D0→K
S0p+p- Dalitz plot BES III can do it. ⇒
D0-D0 mixing parameters have been measured in D0→K+π−. CP
violation is found consistent with zero.
Further results are expected. Please see LHCb upgrade talk by
Preema Pais on Friday.
g=(74.0−5.8+5.0 )o
![Page 27: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/27.jpg)
27
Backup
![Page 28: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/28.jpg)
Search for CP asymmetry in B-→D- D0
28
LHCb paper 2018-007
Submitted to JHEP
Dataset:2.0 fb-1 @ √s=7 TeV1.0 fb-1 @ √s=8 TeV
![Page 29: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/29.jpg)
Interference in B→ DK
● No penguin contribution ⇒theoretically clean
● The only CP-violating parameter that can be measured solely in tree-level processes
● g precision is limited by small branching ratios
Best theoretically clean way of measuring g is based on interference between b→cus and b→ucs tree level amplitudes. E.g., B±→DK± followed by D→f and B→DK± followed by D→f, where f is a common final state
29
![Page 30: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/30.jpg)
Atwood-Dunietz-Soni method
30PRL 78, 3357 (1997);
PRD 63, 036005 (2001)D. Atwood, I. Dunietz and A. Soni,
Doubly Cabibbo suppressed (DCS) D decays can be used tomeasure g. E.g. [K-p+]K- can be reached in two ways:● Cabibbo favored (CF) B-→D0K- followed by DCS D0→K+p-
● DCS B-→D0K- followed by CF D0→K+p-
![Page 31: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/31.jpg)
Gronau-London-Wyler method
31
СР eigenstate of D-meson is used (DCP).
CP-even : DCP K+K–, π+ π –
RCP=Br (B→DCP K ) /Br (B→DCP π )
Br (B→D0 K ) /Br (B→D0 π )=1+r B
2 +2 rB cos δ cos γ
Double ratio:
ΑCP=Br (B−
→DCP K−)−Br (B+
→DCP K+)
Br (B−→DCP K−
)+Br (B+→DCP K+
)=
2 rB sin δ sin γ
1+r B2 +2 r Bcos δ cos γ
СР-asymmetry:
2 equations, 3 unknowns ),,( gdBr
[Phys. Lett. B 253 (1991) 483][Phys. Lett. B 265 (1991) 172]
g
g
![Page 32: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/32.jpg)
Dalitz method
32[A. Bondar, unpublished (2002)][A. Giri, Yu. Grossman, A. Sofer, J. Zupan, PRD 68, 054018 (2003)]
Information from Dalitz plot analysis of DKS
0p+p- from B±->DK±
Dalitz plot density: ds(m+
2, m-2) ~ |A|2dm
+2dm
-2, where m
±2 = m2(K
S0p±)
Flavour D amplitude: AD(m
+2, m
-2)
CP -conservation in DKS
0p+p- decays: AD(m
+2, m
-2) = A
D(m
-2, m
+2)
Amplitude of DKS
0p+p- from B+DK+ :
AB (m
+2, m
-2) = A
D (m
+2, m
-2) + r
BeidB + ig A
D(m
-2, m
+2) =
Required to know phase diference between AD(m+2, m-
2) and AD(m-
2, m+2). Taken from e+e-DD (CLEOc)
![Page 33: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/33.jpg)
GGSZ method
33[A. Giri, Yu. Grossman, A. Sofer, J. Zupan, PRD 68, 054018 (2003)]
)](2[ 2iiiiiBiBi ysxcKKKrKhN
Number of events in B-plotNumber of events in D0-plot: Ki
C (m+2 , m−
2)=cos( δD(m+
2 , m−2)−δ D(m−
2 ,m+2))
S (m+2 , m−
2)=sin (δD(m+
2 ,m−2)−δD(m−
2 , m+2))
PCP±(m+2 ,m−
2)=|f D± f̄ D|
2=PD+ P̄D±2√PD P̄D C
PCorr(m+2 , m−
2 , m+' 2 , m−
' 2)=|f D f̄ D'− f̄ D f D
'|2=
=PD P̄D'+ P̄D PD
'−2√PD P̄D PD
' P̄D'(C C'
+S S')
DCPKSπ+π–:
ψ(3770)(KSπ+π–)D (KSπ+π–)D :
where)cos( 3d Brx
y±=r Bsin (δ±ϕ3 )Free parameters
![Page 34: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/34.jpg)
g combination
34LHCb CONF 2018-002
![Page 35: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/35.jpg)
g combination
35LHCb CONF 2018-002
![Page 36: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/36.jpg)
GGSZ systematic uncertainties
36
LHCb paper 2018-017
![Page 37: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/37.jpg)
D0-D0 mixing and CP violation by D0→K+π−
37Phys Rev D97, 031101 (2018)
![Page 38: Measurement of the CKM angle charm mixing and … of the CKM angle g charm mixing and CP violation at LHCb Outline: LHCb detector & data taking Measurements of CKM angle g Determination](https://reader031.vdocuments.us/reader031/viewer/2022022108/5c03e45309d3f203258d686f/html5/thumbnails/38.jpg)
Interference in B→ DK
Neglible theoretical uncertainty (Zupan and Brod 2013)Theory uncertainty on ~10-7 - [arXiv:1308.5663]
38