d 0 mixing and cp violation
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B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 1 FPCP09, Lake Placid, May 2009
Boštjan GolobBelle & Belle II
University of Ljubljana, Jožef Stefan Institute
D0 Mixing and CP Violation
1. Phenomenology2. Measurements 3. Decays to CP eigenstates 4. Hadronic WS decays 5. t-dependent Dalitz analyses6. Average7. Constraints8. Outlook
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 2 FPCP09, Lake Placid, May 2009
1. Phenomenology
Time evolution flavor states ≠ Heff eigenstates: (defined flavor) (defined m1,2 and 1,2)
002,1 DqDpD
)0()( 2,12,12,1 tDetD ti
;2
; 2121
ymm
xttmi
etyix
Dp
qt
yixDtD 2000
2sinh
2cosh)(
|x|, |y| << 1
P0q1
q2 q1
P0q2
P0 = K0, Bd0, Bs
0 and D0
SM: |x|, |y| O(10-2)
D0 mixing is FCNC of u-type quarks
Decay time distribution of experimentally accessible states D0, D0
sensitive to mixing parameters x and y, depending on final state
2
000
2
)(Df
yix
p
qDfe
dt
fDdN t
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 3 FPCP09, Lake Placid, May 2009
1. Phenomenology
Oscillation frequency
Bs Bd D0
P(P0 P0)P(P0 P0)
Thus the system of the world only oscillates around a mean state from which it never departs except by a very small quantity Marquis de Laplace (1749 -1827)
x=26, y=0.15 x=0.8, y=0
x=0.01, y=0.01
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 4 FPCP09, Lake Placid, May 2009
D0: first two quark generations;CKM elements ≈ real;
using CKM unitarity:
below current exp. sensitivity; signals New Physics
1. Phenomenology
CP violationVcs
Vus*
D0
K-
K+
)(
0
0
0
0
0
0
2/1
)2/1(
),2
1(,2
1
,
fi
D
DM
MD
D
eA
RA
Df
Df
p
q
A
p
qA
Df
Df
RDf
Df
parameterization: RD ≠1: Cabibbo suppression
AD ≠0: CPV in decay AM ≠0: CPV in mixing ≠0 : CPV in interference
)(VV
VVVV -
udcd
ubcbuscs
3*
** 10~Imarg O
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 5 FPCP09, Lake Placid, May 2009
2. Measurements - general
Common methods
D*+ →D0s+
charge of s flavor of D0; M=M(D0s)-M(D0) background reduction
Experiments
p*(D*) > 2.5 GeV/c (or impact parameter) eliminates D0 from b → c
BelleBaBar
Cleo-c
CDF II
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 6 FPCP09, Lake Placid, May 2009
3. Decays to CP eigenstates
CP even final state;no CPV: CP|D1> = |D1> =1/1; K-+: mixture of CP states =f(1/1,1/2)
D0 → K+K- / +-
yxA
y
KK
Ky
CPVno
M
CP
sin2
cos
1)(
)(
S. Bergman et al., PLB486, 418 (2000)
Belle, PRL 98, 211803 (2007), 540fb-1
AM, : CPV in mixing and interference
exp. issues: - good S/N (tagged decays) - precise modeling of decay-t resolution needed
)%25.032.031.1( CPy
yCP=(1.24±0.39±0.13)%
BaBar, PRD78, 011105 (2008), 384fb-1
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 7 FPCP09, Lake Placid, May 2009
)%08.036.026.0( A
3. Decays to CP
eigenstatesCPV
intmixfdec
fCP
aaa
fDfD
fDfDA
)()(
)()(00
00
)%15.030.001.0( ABaBar, PRD78, 011105 (2008), 384fb-1
t-dependent
Belle, PRL 98, 211803 (2007), 540fb-1t-integrated:
t-dependent:
0sincos2
)()(
)()(00
00
CPVno
M xyA
KKDKKD
KKDKKDA
related meas. D0 → KS
-- CP= -1 (KS)-- CP= +1 (a0(980)KS)
CPCP
CPCP y
fy
f
1)1(
1' 11
)%52.061.011.0( CPy
exp. issues: un-tagged decays; worse t due to Ks ; comparison of topologically equal decays → reduced effects of resolution in <t>
’ ’’’’
m(K+K-)
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 8 FPCP09, Lake Placid, May 2009
4. WS decays
D*+ → D0 slow+ D0 → D0 → K+ -
DCS decays interference;
t
mixinterf
D
DCS
D etyx
tyRR
tDK
2
22
.
20
4
'''
)(
sincos'
sincos'
xyy
yxx
t-dependence to separate DCS/mixed
BaBar, PRL 98, 211802 (2007), 384fb-1
12
345
likelihoodcontours
3.9
Belle, PRL 96, 151801 (2006), 400fb-1
: unknown strong phase DCS/CF
CDF, PRL 100, 121802 (2008), 1.5fb-1
CPV allowed:separate D0 and D0 tags(x’2,y’,RD) → (x’±2, y’±,RD
±)
MM
MMM
DD
DDD RR
RRA
RR
RRA
results of similar accuracy
AD = (-21 ± 52 ± 15) ·10-3
exp. issues: - signif. background in WS; - accurate resol. f. param.; - stat. issues for x’2<0;
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 9 FPCP09, Lake Placid, May 2009
D0 →KS +-
different types of interm. states; CF: D0 → K*-+; DCS: D0 → K*+- ; CP: D0 → 0 KS
if f = f relative phases determined (unlike D0 → K+-);
t-dependence: regions of Dalitz plane → specific t dependence f(x, y);
5. t-dependent Dalitz
titi
titi
S
eemmp
q
eemm
tDKtmm
21
21
),(2
1
),(2
1
)(),,(
22
22
022
A
A
M
1,2=f(x,y); n.b.: K+-:x’2, y’
m±2 = m2(KS±),
t
access directly x, y
D0→f
D0→f
exp. issues: - model system.; - direct meas. x, y; - any f = f: sensitivity to x depending on a priori unknown strong phase variation
radpq
yx
)09.024.0(,86.0/
)%24.033.0()%,29.080.0(
30.028.0
09.010.0
29.030.0
14.010.0
16.013.0
Belle, PRL 99, 131803 (2007), 540fb-1
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 10 FPCP09, Lake Placid, May 2009
6. AverageAverage of results K+K-
K+-
KS-+ RM
2 fit including correlationsamong measured quantities
2/n.d.f.=25.3/20
http://www.slac.stanford.edu/xorg/hfag/charm/
(x,y)≠(0,0): 9.8 ;CP even state heavier and shorter lived;no CPV within 1
CP
V
uncertainty
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 11 FPCP09, Lake Placid, May 2009
8. Outlook
HFAG 2 fit
E. Barberio et al. (HFAG), arXiv:0808.1297& http://www.slac.stanford.edu/xorg/hfag/
1, 2, 3 @ 50 ab-1
50 ab-1
only KK/, K and Ks projected sensitivities included
expected sensitivity
)%3.01.0(
049.001.0
055.0919.0
)%001.0336.0(
6.45.24
)%062.0798.0(
)%087.0793.0(
D
D
K
A
rad
p
q
R
y
x
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 12 FPCP09, Lake Placid, May 2009
7. Constraints on NP constraints from mixing
21 NP models considered →17 with useful constraints; improved existing constraints; examples:
E. Golowich et al., PRD76, 095009 (2007)
D0 D0iL
l kRd~
iLl
kRd~
R couplings
kRd
m~
[GeV]
R SUSY:
xD=1.00%±0.25%constraint
4th generation fermion
mb’ [GeV]
|Vub’Vcb’|
xD=1.00%±0.25%constraint
xD=1.00%±0.08%constraint (50 ab-1)
xD=1.00%±0.08%constraint (50 ab-1)
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 13 FPCP09, Lake Placid, May 2009
::0,
:sincossincos
sincossincos
sincossincos
33
33
2,12,1
,
32
22
1
32
22
1
TCPd
dd
d
8. Outlook unexploited possibilities with B-factory data T-odd moments: D →KK
charmed baryon decays: c →, → p exp. issues: - unpolarized c; - p, p detector asymmetry
DCPV can be induced by FSI CPV
: (KK, plane);
exp. issues:-Br(D →KK) 1/2 Br(D →KK);- angular analysis
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 14 FPCP09, Lake Placid, May 2009
Conclusion
• D mixing and CPV are a unique handle to test FCNC of u-like quarks
• Important constraints on NP models from existing results (yet to be fully confronted with other experimental constraints)
• B-factories have not yet spoken the final word (only part of possible measurements done)
• Super-B factory can reach (x,y) 5x10-4, (ACP ~ x sin, AM y cos) 5x10-4
(possible evidence for NP)
there may be hidden treasures in charm physics....
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 15 FPCP09, Lake Placid, May 2009
Supplementary slides
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 16 FPCP09, Lake Placid, May 2009
Phenomenology more
n nD
Cw
Cw
D
Cw
D iEM
DHnnHD
MDHD
MiM
0110
02012 2
1
2
1)
2(
055
02
222**
2
2020 |)1()1(|
)(
4DcucuD
m
mmVVVV
GDHD
c
dsusudcdcs
FCw
short distance:
DCS SU(3) breakingG. Burdman, I. Shipsey, Ann.Rev.Nucl.Sci. 53, 431 (2003) |x| ~ O(10-5)
long distance:
absorptive part (real interm. states) ydispersive part (off-shell interm. states) x
D0 D0
K+
K-
I.I. Bigi, N. Uraltsev, Nucl. Phys. B592, 92 (2001);A.F. Falk et al., PRD69, 114021 (2004)
|x|, |y| ~ O(10-2)
D0 mixing: rare process in SM;possible contrib. from NP
x and y in SM 2nd order perturb.:
c
u
u
c
d, s, b d, s, b
W+
W-
D0 D0
Vci*
Vcj
Vuj*
Vui
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 17 FPCP09, Lake Placid, May 2009
continuum production
A) Experiments
* c
c
e+e- → (3770) → D0D0, D+D- (coherent C=-1 state); ~800 pb-1 of data available at (3770) 2.8x106 D0D0
3.5 fb-1 on tape(D0; pt>5.5 GeV,|y|<1)≈13 b50x109 D0’s
very diverse exp. conditions
d(D0)/dpt [nb/GeV]
(c c) 1.3 nb (~109 XcYc pairs)
Measurements – experim. more
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 18 FPCP09, Lake Placid, May 2009
K-+
Decays to CP eigenstates moreBelle, PRL 98, 211803 (2007), 540fb-1Fit
simultaneous binned likelihood fit to K+K- /K-+/+- decay-t, common free yCP
)(')'(/' tBdttteN
dt
dN t R
R : ideally each i Gaussian resol. term with fraction fi; : described by 3 Gaussians
N
i kikki tsttGwftt
1
3
10 ),,'()'( R
= 408.7±0.6 fs
event-by-event t
parameters of R depend slightlyon data taking conditions
trec-tgen/t
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 19 FPCP09, Lake Placid, May 2009
Decays to CP eigenstates more
yCP=(1.24±0.39±0.13)%
confirmation: BaBar, arXiv:0712.2249, 384fb-1
yCP currently most preciselymeasured param.
D0 → K+K- / +-
sincossin)1(cos
)cossin)(1(1,)cossin)(1(1
xyAxAyAA
yxAAyxAA
MDMff
ff
DMfDMf
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 20 FPCP09, Lake Placid, May 2009
)%08.036.026.0( A
3. Decays to CP
eigenstatesCPV
intmixfdec
fCP
aaa
fDfD
fDfDA
)()(
)()(00
00
)%15.030.001.0( A
Belle, PLB 670, 190 (2008), 540fb-1
BaBar, PRD78, 011105 (2008), 384fb-1
t-integrated ACP
meas =A + AFB + ACP
f
A : comparison of tagged/untagged
(D*+ →D0+),D0 →K-+ AFB: asymmetric f(cosCMS)
exp. issues: - meas. in bins of pD, cosD
due to A ( determined by NK
tag); - A
can be used in other meas.;
t-dependent
)%13.034.000.0( KKCPA
)%11.030.043.0( KKCPA
Belle, PRL 98, 211803 (2007), 540fb-1t-integrated:
t-dependent:
0sincos2
)()(
)()(00
00
CPVno
M xyA
KKDKKD
KKDKKDA
BaBar, PRL 100, 061803 (2007), 386fb-1
ACPKK ACP
|cosCMS|
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 21 FPCP09, Lake Placid, May 2009
3. Decays to CP eigenstates related meas.
D0 → KS
CP odd final state; (KS)= 1/2 > 1/1 =(K+K-)
exp. issues: - un-tagged decays; - worse t due to Ks - comparison of topologically equal decays → reduced effects of resol. in <t>
-- CP= -1 (KS)-- CP= +1 (a0(980)KS)
CPCP
CPCP y
fy
f
1)1(
1' 11
)'''('''
'''11
CPCPCP ffy
’ ’’’’
m(K+K-)
)%52.061.011.0( CPyBelle, preliminary, 600fb-1
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 22 FPCP09, Lake Placid, May 2009
Decays to CP eigenstates more
methodBelle, preliminary, 600fb-1
D0 → Ks
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 23 FPCP09, Lake Placid, May 2009
Decays to CP eigenstates more
Dalitz model CP=-1 Ks
CP=+1 a0(980)Ks
a0(1450)Ks
f0(980)Ks
f0(1370)Ks
f2(1270)Ks
flavour spec. K-a0(980)+
K+a0(980)-
K-a0(1450)+
Belle, preliminary, 600fb-1 D0 → Ks
model affects only fraction of CP=+1 states in individual mass interval; small model syst. uncertainty
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 24 FPCP09, Lake Placid, May 2009
Decays to CP eigenstates more
syst. uncertainty on Belle, preliminary, 600fb-1
D0 → Ks
from MC (stat.)
data fluctuations
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 25 FPCP09, Lake Placid, May 2009
WS decays more C) WS decays (non-CP)
D*+ → D0 slow+ D0 → D0 → K+ -
BaBar, PRL 98, 211802 (2007), 384fb-1
Belle, PRL 96, 151801 (2006), 400fb-1
CDF: trigger: h+h- from second. vtx; NWS/NRS vs. t/ from M, M, imp. param.;
NWS/NRS
CDF, PRL 100, 121802 (2008), 1.5fb-1
NWS~13x103
12
34
CDF, PRL 100, 121802 (2008), 1.5fb-1
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 26 FPCP09, Lake Placid, May 2009
t-dependent Dalitz more
rad
pq
yx
)09.024.0(
86.0/
30.028.0
09.010.0
29.030.0
14.010.016.013.0
)%24.033.0()%29.080.0(
Belle, PRL 99, 131803 (2007), 540fb-1
D0 →KS +-
most accurate x
K*(892)+
K*X(1400)+
K*(892)-
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 27 FPCP09, Lake Placid, May 2009
t-dependent Dalitz more
2222
**2
20
4
)(t
yxAytAAxtAAA
e
tPffffffft
K
mmmmiiff
mmii
r
ir
i
mmii
r
ir
i
xteemmmmaaxtAA
emmeaemmaeamm
emmeaemmaeamm
r
r
11
)),(),(()(22
21
22
2111
*
),(22
211
1
22
211
22
21
),(22
211
1
22
211
22
21
22
21
22
2111
22
2111
22
2111
|),(|),(
|),(),(1),(
|),(),(1),(
ff
ff
ff
M|M|
M|A
M|A
BaBar, Lepton Photon 07, 384fb-1
D0 →KS0 BaBar, PRL97, 221803 (2006), 384fb-1
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 28 FPCP09, Lake Placid, May 2009
5. t-dependent Dalitz Belle, PRL 99, 131803 (2007), 540fb-1
D0 →KS +-
related meas. D0 →K+ -0
KK
KKxyyyxx
sincos''sincos''
BaBar, PRL97, 221803 (2006), 384fb-1
no mixing point 0.8% C.L.
radpq
yx
)09.030.0
28.024.0(,
09.0
10.0
29.0
30.086.0/
)%24.033.0()%,29.080.0(14.0
10.0
16.0
13.0
K: unknown strong phase shift DCS/CF
t
mix
f
interf.
ffff
DCS
f
etyx
A
txyAA
AtDK
]
||[
222
2
2200
4
''''||
)sin''cos''(||||
)(
exp. issues: - model system.; - direct meas. x, y; - any f = f: sensitivity to x depending on apriori unknow strong phase variation
separate WS/RS Dalitz distributions; t-distrib. analogous to D0 →K+ -;
RS t-integratedDalitz analysis;WS Dalitz analysis;
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 29 FPCP09, Lake Placid, May 2009
Average more Expected sensitivities from individual meas.
L = 5 ab-1 L = 50 ab-1 L = 5 ab-1 L = 50 ab-1
(x) 0.14% 0.10% 0.08% 0.05% KsKK, 0 total error :3(y) 0.11% 0.08% 0.06% 0.04% KsKK, 0 total error :3(yCP) 0.16% 0.11%(A) 0.12% 0.07%(ACP) 0.12% 0.07%(x’2) 0.11x10-3 0.09x10-3 0.13x10-3 0.10x10-3
x’2± stat. error •2 (y’) 0.20% 0.16% 0.23% 0.17% y’± stat. error •2(AD) 2.1% 1.7%(RD) 5x10-5 1.5x10-5 7x10-5 2x10-5
RD± stat. error •2
(|q/p|) 0.13 0.09 0.08 0.05 KsKK, 0 total error :30.12 rad 0.07 rad 0.07 rad 0.04 rad KsKK, 0 total error :3
i.e. assumingsens. same asin Ks
total errorscaled
for CPV allowed fit
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 30 FPCP09, Lake Placid, May 2009
Average more Projected sensitivities from average
)%0.12.0(
08.001.0
08.091.0
)%004.0336.0(
4.64.24
)%09.080.0(
)%12.080.0(
D
D
K
A
rad
p
q
R
y
x
)%0.12.0(
051.001.0
055.0910.0
)%003.0336.0(
7.45.24
)%06.080.0(
)%07.080.0(
D
D
K
A
rad
p
q
R
y
x
)%3.01.0(
049.001.0
055.0919.0
)%001.0336.0(
6.45.24
)%062.0798.0(
)%087.0793.0(
D
D
K
A
rad
p
q
R
y
x
)%26.01.0(
03.001.0
036.0914.0
)%001.0336.0(
7.36.24
)%045.0800.0(
)%055.0793.0(
D
D
K
A
rad
p
q
R
y
x
5 ab-1 5 ab-1, KsKK, 0 50 ab-1 50 ab-1, KsKK, 0
LHCb, 10 fb-1 (5 y): (x’2)~6x10-5, (y’)~0.9x10-3
(yCP)~0.05%main sensitivity on x, |q/p|, from t-dependent Dalitz analyses of Ks, 0, KsKK
+ assuming ACP=AD (AD) ~ 0.1%
B. Golob, Ljubljana Univ., JSI D0 Mixing and CPV 31 FPCP09, Lake Placid, May 2009
Average more
0 1 2 3 4 5 [rad]
y’=
yco
s-x
sin
[%]
1.0
0.5
0
-0.5
-1.0
y’ measured
m
easu
red
(3770) →D0D0
constraints average direct meas. (fit w/o external input)
0 1 2 3 4 5 [rad]
cos
1
0
-1
top related