Recent results on D 0 m ixing from Belle
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Transcript of Recent results on D 0 m ixing from Belle
B. Golob, Belle D0 Mixing 1 Lepton Photon ‘07, Daegu
B. GolobUniversity of Ljubljana
Belle Collaboration
Outline1. Introduction2. Phenomenology3. Measurements K+K-/+-
KS++
CPV4. Prospects & Summary
Recent results on D0 mixing from Belle Lepton Photon Interactions 2007
Introduction
Dual role of charm - experimental tests of theor. predictions (most notably of (L)QCD); improve precision of CKM measurements (B physics);
- standalone field of SM tests and search for new phenomena (SM and/or NP) → D0-D0 Mixing
E. Golowich et al., arXiv:0705.3650
21 different NP models:17 of those → constraints in parameter space from established D0 mixing rate <~10-4
example:4th fermion family(severly constrained fromother measurements as well)
mix
ing
am
pl.
|Vub’Vcb’|
mb’=500 GeV
mb’=200 GeV
B. Golob, Belle D0 Mixing 2 Lepton Photon ‘07, Daegu
(c c) 1.3 nb (Belle luminos.:~850·106 XcYc pairs)
(4S):
Introduction
3(4) layerSi det.
Central Drift Chamber
AerogelCherenkov(n=1.015-1.030)
1.5T SC solenoid
e- 8 GeV
e+ 3.5 GeV
EM calorimeterCsI (16X0)
and KL
Counter(14/15 layersRPC+Fe)
Ldt
20072000
700 fb-1
t/(D0)
t/(D0)=1/3
(K±) ~ 85%(±→K±) 10%for p < 3.5 GeV/c
<t>/(D0)~ 1/2
D0→ K-+
B. Golob, Belle D0 Mixing 3 Lepton Photon ‘07, Daegu
D*+ →D0+slow, D0 →K-+
M=M(Kslow)-M(K)
D0 - D0 Phenomenology Mixing phenomena X0 = K0, Bd
0, Bs0 and D0
t-dependent Schrödinger eq.:
mass eigenstates: decay time evolution:
002,1 XqXpX
X0q1
q2
q2
q1
X0
)(
)(
2)(
)(0
0
0
0
tX
tXi
tX
tX
ti ΓM
CP eigenstates if q/p=1;
propagate in t according to distinct eigenvalues;
tm
iet
yixX
p
qt
yixXtX
)2
1(000
2sinh
2cosh)(
2;
2; 212121
ymm
x
Decay time distribution of experimentally accessible states X0, X0 sensitive to mixing parameters
B. Golob, Belle D0 Mixing 4 Lepton Photon ‘07, Daegu
I.I. Bigi, N. Uraltsev, Nucl. Phys. B592, 92 (2001); A.F. Falk et al., PRD69, 114021 (2004)
|x|, |y| < O(10-2)~
Belle measurements
- semileptonic decays,
D0 → K(*) l n
- hadronic decays to non-CP final state D0 → K+-
- hadronic decays to multi-body final state, D0 → KS +-
- decays to CP final state, D0 → K+K-/+-
Measurements
arXiv: 0704.1000, 540 fb-1, subm. to PRL
common:D*+ →D0s
+
charge of s tags the flavor of initially produced D0;
p*(D*) > 2.5 GeV/celiminates D meson production from b → c
selection determined “blindly”PRL 98, 211803 (2007), 540fb-1
PRD72, 071101 (2005), 253 fb-1
PRL96, 151801 (2006), 400 fb-1
B. Golob, Belle D0 Mixing 5 Lepton Photon ‘07, Daegu
Measurements K+K- / +-
PRL 98, 211803 (2007), 540fb-1
D0 → K+K- / +-
CP even final state;in the limit of no CPV: CP|D1> = |D1> measure 1/1
002,1 XqXpX
y
xAyKK
Ky
CPVno
MCP
sin
2
1cos1
)(
)(
S. Bergman et al., PLB486, 418 (2000)
AM, : CPV in mixing and interference
Signal
sideband
M(K+K- ) , Q=M(K+K- s)- M(K+K- )- M(), t, selection optimized on MC
K+K- K-+ +-
Nsig 111x103 1.22x106 49x103
P 98% 99% 92%B. Golob, Belle D0 Mixing 6 Lepton Photon ‘07, Daegu
Measurements K+K- / +-
Fitsimultaneous binned likelihood fit to K+K- /K-+/+- decay-t, common free yCP
)(')'(/' tBdttteN
dt
dN t R
= 408.7±0.6 fs
event-by-event t
K-+
parameters of R depend slightlyon data taking conditions
PRL 98, 211803 (2007), 540fb-1
B. Golob, Belle D0 Mixing 7 Lepton Photon ‘07, Daegu
PDG=410.1±1.5 fs
constructed usingevent-by-event t
M sideband
Measurements K+K- / +-
Result
K+K-/+-
and K-+ratio
difference of lifetimesvisually observable
evidence for D0 mixing(regardless of possible CPV)
3.2 from zero (4.1 stat. only)
2/ndf=1.084 (ndf=289)
+
negligible CPV, yCP=y
PRL 98, 211803 (2007), 540fb-1
B. Golob, Belle D0 Mixing 8 Lepton Photon ‘07, Daegu
)%25.032.031.1(CPy ±1
Measurements KS +-
arXiv: 0704.1000, 540 fb-1, subm. to PRL
t-dependent Dalitz analysis different decays identified through Dalitz analysis; CF: D0 → K*-+
DCS: D0 → K*+-
CP: D0 → 0 KS
their relative phases determined (unlike D0 → K+-);
t-dependence:
titi
titi
S
eemmp
q
eemm
tDKtmm
21
21
),(2
1
),(2
1
)(),,(
22
22
022
A
A
M
< f | D0 >
< f | D0 >
1,2=f(x,y); n.b.: K+-:x’2, y’
NRr iNR
ir eammBeamm
),(),( 2222A
m±2 = m2(KS±)
M = < f | D0(t) > analogous
sum of intermediate states
B. Golob, Belle D0 Mixing 9 Lepton Photon ‘07, Daegu
Measurements KS +-
),m(m),m(mp
q-
2222,1 MM
arXiv: 0704.1000, 540 fb-1, subm. to PRL
fit M(m-2,m+
2,t) to data distribution x, y
Fit no CPV:
M(KS +- ) and Q= M(KS +-s)- M(KS +-)- M();3 signal region in M, Q
Signal
Nsig= (534.4±0.8)x103
P 95%
Dalitz model
13 BW resonances, non-resonant contr.;comb. bkg.: from M sideband
t
Msignalrnd slow pcombin.
NRr iNR
ir eammBeamm
),(),( 2222A
B. Golob, Belle D0 Mixing 10 Lepton Photon ‘07, Daegu
Measurements KS +-
arXiv: 0704.1000, 540 fb-1, subm. to PRL
Dalitz projection of fit
K*(892)+
K*X(1400)+
K*(892)-
test of S-wave contr. (f0, 1,2): K-matrix formalism
Results (fit fractions, phases) in agreement with (measurement of 3)
PRD73, 112009 (2006)
B. Golob, Belle D0 Mixing 11 Lepton Photon ‘07, Daegu
Measurements KS +-
arXiv: 0704.1000, 540 fb-1, subm. to PRL
Decay-t projection of fit
t [fs]
= 409.9±0.9 fs
most sensitivemeas. of x;
Cleo, PRD72, 012001 (2005)x = 1.8 ± 3.4 ± 0.6%y = -1.4 ± 2.5 ± 0.9 %
PDG=410.1±1.5 fs
comb.bkg.
PRD72, 071101 (2005), 253 fb-1
D0 → K(*) l PRL96, 151801 (2006), 400 fb-1
D0 → K+ -
2-d 68% C.L. region
B. Golob, Belle D0 Mixing 12 Lepton Photon ‘07, Daegu
)%24.033.0()%29.080.0(
14.010.016.013.0
yx
2-d 68% C.L. region
D0 → K+K-/+-
PRL 98, 211803 (2007), 540fb-1
Measurements CPV
CPV in D0 systemfirst two generations involved:
0;1)2
1(/ MM A
Apq
)10(~2
~ 352
OA
t distributions depend also on CPV parameters;x, y at upper limit of SM expectation → search for CPV; at current level of sensitivity positive signal clear indication of NP;
Wolfensteinparameter.
CPV in decay: 1/ ff AA (singly Cabibbo supp. decays only)
CPV in mixing:
0;0)1(
2/1ImIm
i
DD
M
f
f eAR
A
A
A
p
q
CPV expected to be small in SM
CPV in interf. mix./decay:
B. Golob, Belle D0 Mixing 13 Lepton Photon ‘07, Daegu
Measurements CPV
CPV in D0 → K+K- / +-
sin2
1cos1
)(
)(xAy
KK
Ky MCP
sincos2
1
)()(
)()(00
00
xyAKKDKKD
KKDKKDA M
CPV in D0 → KS +-
include |q/p| (AM) and as additional free param.
separate for D0, D0
95%C.L.
B. Golob, Belle D0 Mixing 14 Lepton Photon ‘07, Daegu
)%15.030.001.0( A
09.010.0
0.290.30 0.86 |q/p|
rad 0.09) (-0.24 31.028.0
Measurements CPV
CPV in D0 → +-0
B. Golob, Belle D0 Mixing 15 Lepton Photon ‘07, Daegu
CPV in decay, integrated over t and Dalitz space
D0 → +-0 D0 → +-0
)()(
)()(0000
0000
DD
DDACP
)%31.141.043.0( CPA )%1( 910CPA
540 fb-1, preliminary
Cleo, PRD 72, 031102 (2005)
Belle
prelim
inary
Measurements average
Combination, no CPV all available meas.; observables (yCP, x, ...) → x, y, K, RD
sum of likelihood curves, non-Gaussian shapes accounted for
HFAG charm, http://www.slac.stanford.edu/xorg/hfag/charm/index.html
B. Golob, Belle D0 Mixing 16 Lepton Photon ‘07, Daegu
% ) (0.66 y 0.200.21
% ) (0.87 x 0.340.30
Measurements average
Combination, CPV observables (A, x, ...) → |q/p|, , AD, x, y, RD, K
2 minimization, non-Gaussian shapes not accounted for
HFAG charm, http://www.slac.stanford.edu/xorg/hfag/charm/index.html
B. Golob, Belle D0 Mixing 17 Lepton Photon ‘07, Daegu
% 0.21) (0.69 y
% ) (0.84 x 0.340.32
0.200.23 0.88 |q/p|
rad ) (-0.09 0.190.17
Prospects & Summary Super-B factory extrapolation of existing Belle results
L = 5 ab-1 L = 50 ab-1
(x) 0.1% 0.07%(y) 0.1% 0.07%(AM) 0.1 0.070.1 rad 0.07 rad
Summary 2007: D0 mixing established (slowest of all neutral mesons) Belle presented first evidence for D0 mixing (yCP), most precise x meas.; confirmation in D0 → K+K-, KS+-, other sensitive modes? (esp. x, from Dalitz analyses, sign)? combination of existing D0 mixing results:
established at ~5 ; x,y ~ O(10-2); (x,y) ~ 0.3%; observed mixing may (not) be arising from SM → important CPV search existing facilities: any CPV indication of NP Super-B: allows to test CP asymmetries to few 10-4 (SM expectations)
B. Golob, Belle D0 Mixing 18 Lepton Photon ‘07, Daegu
LHCb, 10 fb-1 (5 y): (x’2)~6x10-5, (y’)~0.9x10-3
(yCP)~0.05%
Introduction (bckup) Physics of c-hadrons increased interest at B-factories in recent years
Dual role of charm
standalone field of SM tests and search for new phenomena (SM and/or NP)
experimental tests of theor. predictions (most notably of (L)QCD); improve precision of CKM measurements (B physics);
√s = M((4S))c2=10.58 GeV
B-factory, c-factory
(B B) 1.1 nb (~750·106 BB pairs)
(c c) 1.3 nb (~850·106 XcYc pairs)
→ D0-D0 Mixing
B. Golob, Belle D0 Mixing 19 Lepton Photon ‘07, Daegu
Phenomenology bckup
Mixing phenomena in course of life neutral meson X0 can transform into anti-meson X0
X0 = K0, Bd
0, Bs0 and D0
t-dependent Schrödinger eq.:
mass eigenstates: eigenvalues:
002,1 XqXpX
X0q1
q2
q2
q1
X0
)(
)(
2)(
)(0
0
0
0
tX
tXi
tX
tX
ti ΓM
q
p
q
p
iMiM
iMiM
2,1*12*
12
1212
22
22
2
2*
*,
222 1212
1212
2
2,12,1
12122,1
iM
iM
p
qimiM
p
qiM
CP eigenstates if q/p=1
B. Golob, Belle D0 Mixing 20 Lepton Photon ‘07, Daegu
D0 - D0 Phenomenology (bckup)
Mixing description observation of K0: 1950 (Caletch) mixing in K0: 1956 (Columbia) observation of Bd
0: 1983 (CESR) mixing in Bd
0: 1987 (Desy) observation of Bs
0: 1992 (LEP) mixing in Bs
0: 2006 (Fermilab) observation of D0: 1976 (SLAC) mixing in D0: 2007 (KEK, SLAC) (evidence of)
c
u
u
c
d, s, b d, s, b
W+
W-
D0 D0
Vci*
Vcj
Vuj*
Vui6years
4years
14years
31years
),( 2
,,,
2**00j
bsdjiiujcjuicieff mmVVVVDHD
F
if mi = mj due to CKM unitarity: no D0 D0 mixing
|Vcb*Vub|<< |Vcs*Vus|, |Vcd*Vud|
mainly d,s contrib.; md ~ ms mixing small
(as opposed to Bd0, where term
with mt2 |Vtb* Vtd|2 dominates)
d-like quarks in loop
B. Golob, Belle D0 Mixing 21 Lepton Photon ‘07, Daegu
D0 - D0 Phenomenology (bckup)
c
u
u
c
d, s, b d, s, b
W+
W-
D0 D0
Vci*
Vcj
Vuj*
Vui
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
x and y in SM 2nd order perturb.:
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
B. Golob, Belle D0 Mixing 22 Lepton Photon ‘07, Daegu
D0 - D0 Phenomenology (bckup) Oscillations
visually unobservabledeviation from pure exponential
~ Bs0
more difficult to observeoscillations within
B. Golob, Belle D0 Mixing 23 Lepton Photon ‘07, Daegu
right sign (RS)
Semileptonic (bckup) PRD72, 071101 (2005), 253 fb-1
Semileptonic decays Wrong charge combinations (WS):
D*+ → D0 slow+ D0 → D0 → K(*)+ e-
no “DCS” decays NWS/NRS = RM (x2+y2)/2
Reconstruct : missing momentum with kinematic constraints
Signal:M = M(Keslow) - M(Ke)
tetyx
tDK 2
2220
4)(
0; ff AAKf
NRS = (229.45 ± 0.69) ·103
B. Golob, Belle D0 Mixing 24 Lepton Photon ‘07, Daegu
Semileptonic (bckup) PRD72, 071101 (2005), 253 fb-1
Result:
RM = (0.20 ± 0.47 ± 0.14) ·10-3
RM < 1.2 · 10-3 95% C.L.
dominating systematics from limited bkg. statistics (embedded slow)
Decay time: reduce bkg., increase sensitivity;
<t >(bkg., RS) < <t >(mix. signal)
6 bins in 1 < t < 10
iWS
iRS
iRS
iWSiM N
NR
,
,
,
,,
allowed
B. Golob, Belle D0 Mixing 25 Lepton Photon ‘07, Daegu
K+- (bckup)
D*+ → D0 slow+ D0 → D0 → K+ -
DCS decays interference
tDD et
yxtyRRtDK
2
2220
4
''')(
Wrong charge combinations (WS):
Signal:M= M(K)
Q = M(K slow) - M(K) - M()
2D M-Q fit:
NWS = 4024 ± 88
3 M interval
WS
WSrateCF
rateDCSR
xyyyxx
D
sincos'sincos'
PRL96, 151801 (2006), 400 fb-1
3 Q interval
t-dependence to separate DCS/mixed
B. Golob, Belle D0 Mixing 26 Lepton Photon ‘07, Daegu
K+- (bckup)
PRL96, 151801 (2006), 400 fb-1
Decay time: resol. function from RS
(D0) = 409.9 ± 0.7 fs x’2, y’, RD free parameters
Results: RD = (3.64 ± 0.17 ) ·10-3
x’2 = (0.18 ± 0.210.23) · 10-3
y’ = (0.6 ± 4.03.9) · 10-3
95% C.L. (x’2, y’) contourfrequentist, FC ordering
WS t dist.
B. Golob, Belle D0 Mixing 27 Lepton Photon ‘07, Daegu
Measurements K+- bckup
PRL96, 151801 (2006), 400 fb-1
RD = (3.64 ± 0.17 ) ·10-3
x’2 = (0.18 ± 0.210.23) · 10-3
y’ = (0.6 ± 4.03.9) · 10-3
AD = (23 ± 47) ·10-3
AM = (670 ± 1200) ·10-3
Results:
no CPV
CPV
CPV allowed:separate D0 and D0 tags(x’2,y’,RD) → (x’±2, y’±,RD
±)
MM
MMM
DD
DDD RR
RRA
RR
RRA
95% C.L. (x’2, y’) contourfrequentist, FC ordering
(0,0) lies on 96.1% C.L. contour
x’2 < 0.72 ·10-3
-0.99% < y’ < 0.68%no signif. CPV
largest syst. due to p*(D*) selection
B. Golob, Belle D0 Mixing 28 Lepton Photon ‘07, Daegu
K+- BaBar comp. (bckup)
BaBar, hep-ex/0703020, 384fb-1, acc. to PRL
ResultRD = (3.03 ± 0.19) ·10-3
x’2 = (-0.22 ± 0.37) · 10-3
y’ = (9.7 ± 5.4 ) · 10-3
including sys. error
1 2
3
3.9
Comparison
consistent
evidence for (x,y) (0,0)
B. Golob, Belle D0 Mixing 29 Lepton Photon ‘07, Daegu
Prospects bckup perspective (1 ab-1)
1
3
x, y at upper limit of SM expectation search for CPV; at current level of sensitivity positive signal clear indication of NP;
(x) ~ ±0.21%(y) ~ ±0.17%
B. Golob, Belle D0 Mixing 30 Lepton Photon ‘07, Daegu
KS+- syst. (bckup)
D0 → KS+-
arXiv: 0704.1000
M(KS +- ) and Q= M(KS +-s)- M(KS +-)- M();3 signal region in M, Q
B. Golob, Belle D0 Mixing 31 Lepton Photon ‘07, Daegu
KS+- syst. (bckup)
D0 → KS+-
Largestsystematics
arXiv: 0704.1000
model dependence [10-4]: x y -10.3 +0.1 K*0(1430) DCS/CF -15% + 6.9 -2.5 K*2(1430) DCS/CF -30% -1.6 -0.9 K*(1410) DCS & CF -20% -5.1 -4.1 (q2) const. --------------------------------- +10 +6 Total model dep. -14 -8
experimental: x y +7.6 -7.8 p* variation -5.6 -5.7 Dalitz pdf for bkg. from different t bins ----------------------- +9 +8 Total experimental -7 -12
observed discrepancy from
input in MC
statisticaluncertainty:
(x)=29x10-4
(y)=24x10-4
B. Golob, Belle D0 Mixing 32 Lepton Photon ‘07, Daegu
KS+- syst. (bckup)
D0 → KS+-
Largestsystematics
arXiv: 0704.1000
model dependence [10-4]: x y -10.3 +0.1 K*0(1430) DCS/CF -15% +12.5 -4.4 K*2(1430) DCS/CF fixed to K*(892) -6.4 +5.0 K*(1410) DCS & CF fixed to K*(892) --------------------------------- +15 +8 +10 +6 Total model dep. -16 -9 -14 -8
B. Golob, Belle D0 Mixing 33 Lepton Photon ‘07, Daegu
KS+- param. (bckup)
D0 → KS+- parameterization
arXiv: 0704.1000
)(),(),(
)(),(),()(
22222
122220
temmmm
temmmmtDKS
AA
AAM
),(),(:
),(),(
),(),(
2222
2222
2222
mmmmCPVdirectno
eammAeamm
eammAeamm
r
iNRr
ir
r
iNRr
ir
NRr
NRr
AA
A
A
)(),(),(
)(),(),()(
22222
122220
temmmm
temmmmtDKS
AA
AAM
B. Golob, Belle D0 Mixing 34 Lepton Photon ‘07, Daegu
KS+- param. (bckup)
D0 → KS+-
arXiv: 0704.1000
CP=+1 states
),(),(
)(
1),(
2222
222222
00
00
0
mmmm
iMmmMMmm
SS
S
KfKf
ffKf
AA
A
)(),(),(
)(),(),()(
22222
122220
temmmm
temmmmtDKS
AA
AAM
11
)1
exp()()(1
11
10
CPCP y
y
ty
tetDCP
M
Cleo, PRD 63, 092001 (2001)
parameterization as in
B. Golob, Belle D0 Mixing 35 Lepton Photon ‘07, Daegu
KS+- param. (bckup)
D0 → KS+-
arXiv: 0704.1000
CP= -1 states
),(),(
)(),(
2222
2222
2222
00
00
0
mmmm
iMmmMM
mmmm
SS
S
KK
K
AA
A
)(),(),(
)(),(),()(
22222
122220
temmmm
temmmmtDKS
AA
AAM
1
1
)1
exp()()(1
11
20
CPCP y
y
ty
tetDCP
M
Cleo, PRD 63, 092001 (2001)
parameterization as in
B. Golob, Belle D0 Mixing 36 Lepton Photon ‘07, Daegu
KS+- K-matrix (bckup)
D0 → KS+-
scalar
arXiv: 0704.1000
BW formalism:M(1) = 527 ±6 MeV/c2
(1) = 442 ± 10 MeV
M(2) = 1031 ±11 MeV/c2
(2) = 94 ± 6 MeV
qkpqjpjkjk TiTTT 2
K-matrix formalism:unit. relat. for 2-body scatt. trans. operator:
T: NchxNch matrixfor Nch coupled chann.;: density of final states
product. process (init. state non-interactingwith channel j); trans. ampl. unitarity:
qjpqpjj TiFFF ** 2
Nch
qjqj TaF1
satisf. by
defining 1)( KiIKT
unitarity satisf. if KK
product. ampl.:1)( KiIaKF
':5:4
4:3:2:1
)()(5
1
111
KK
aKKiIFj
jj
V.V. Anisovich, A.V. Sarantev, Eur.Phys.J. A16, 229 (2003)BaBar, hep-ex/0507101
parameters taken from:
B. Golob, Belle D0 Mixing 37 Lepton Photon ‘07, Daegu
KS+- eff., resol. (bckup)
D0 → KS+-
efficiency and resol. in M(
arXiv: 0704.1000
rnd s bkg.:
Prnd [(1-fw) M(m-2,m+
2,t) +fw M(m+2,m-
2,t)] R(t)
fw from fit to Q side band: fw= 0.452 ± 0.005diff. w.r.t. fw=0.5 in systematic error
comb. bkg.:
Pcmb B(m-2,m+
2) * ([ (t) + Exp(t) ]R’(t)
parameters from fit to Dalitz and t distrib. of M(KS +- ) sideband(systematics: Dalitz distrib. in different t intervals)
B. Golob, Belle D0 Mixing 38 Lepton Photon ‘07, Daegu
KS+- toy MC (bckup)
D0 → KS+-
arXiv: 0704.1000
MC tests, correct reconstruction of input;
t-projection;
Psig M(m-2,m+
2,t) R(t)
Prnd [(1-fw) M(m-2,m+
2,t) +fw M(m+2,m-
2,t)]
R(t)
Pcmb Msideband(m-2,m+
2,t)
* [ (t) + Exp(t) ]R’(t)
B. Golob, Belle D0 Mixing 39 Lepton Photon ‘07, Daegu
K+K- / +-, M, Q (bckup)
M [GeV/c2]
D0 → K+K- / +-
hep-ex/0703036v2
B. Golob, Belle D0 Mixing 40 Lepton Photon ‘07, Daegu
K+K- / +-, systematics (bckup)
D0 → K+K- / +-
systematics
hep-ex/0703036v2
B. Golob, Belle D0 Mixing 41 Lepton Photon ‘07, Daegu
K+K- only: yCP=(1.25 ±0.39)% A=(0.15 ±0.35)%+- only: yCP=(1.44 ±0.57)% A=(-0.28 ±0.52)%
K+K- / +- resolution (bckup)
Fitsimultaneous 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
K-+
parameters of R depend slightlyon data taking conditions
trec-tgen/t
PRL 98, 211803 (2007), 540fb-1
B. Golob, Belle D0 Mixing 42 Lepton Photon ‘07, Daegu
PDG=410.1±1.5 fs
K+K- / +-, t fit (bckup)
D0 → K+K- / +-
running periods w/ diff. conditions
< t >
fitted t0 of R for K
robust to resol. f. shape; R(t): single Gauss →=3.5%, yCP=0.01%;
no bias, reweigted MC: yCP(out) - yCP(in) < 0.04%;
background P=98% (KK), 99% (K), 92% (); changing data side band/MC signal, yCP = -0.04%; bkg. subtracted / no bkg. subtraction, yCP = -0.07%; bkg. subtracted / MC signal subtr., yCP= -0.03%;
systematic checks
hep-ex/0703036v2
B. Golob, Belle D0 Mixing 43 Lepton Photon ‘07, Daegu
K+K- / +-, t0 (bckup)
D0 → K+K- / +-
fitted t0 of R in diff. run periods and diff. decay modes
hep-ex/0703036v2
B. Golob, Belle D0 Mixing 44 Lepton Photon ‘07, Daegu
K+K- / +-, t0 (bckup)
D0 → K+K- / +-
equal t0 assumption
yCP=t0CP - t0
K / K
from MC cocktail, includingrunning periodswith slight misalign.of SVD
hep-ex/0703036v2
B. Golob, Belle D0 Mixing 45 Lepton Photon ‘07, Daegu
K+K- / +-, bkg t distr. (bckup)
D0 → K+K- / +-
background comparison
small tail ofsignal present inside band, only visible in K sample;
fraction of rnd s
negligible:0.3%, 0.3%, 0.2%KK K
hep-ex/0703036v2
B. Golob, Belle D0 Mixing 46 Lepton Photon ‘07, Daegu
K+K- / +-, KS+- comparison (bckup)
KS +- : (x,y)=(0,0) has C.L. 2.6%
K+K- / +-: y=0 has C.L. 6x10-4
Results
B. Golob, Belle D0 Mixing 47 Lepton Photon ‘07, Daegu
Measurements average (bckup) Combination, no CPV sum of likelihood curves, non-Gaussian shapes accounted
yCPx
HFAG charm, http://www.slac.stanford.edu/xorg/hfag/charm/index.html
B. Golob, Belle D0 Mixing 48 Lepton Photon ‘07, Daegu
% 0.321) (1.122 yCP % 0.334) (0.811 x
Measurements average (bckup) Combination, no CPV sum of likelihood curves, non-Gaussian shapes accounted
y
HFAG charm, http://www.slac.stanford.edu/xorg/hfag/charm/index.html
B. Golob, Belle D0 Mixing 49 Lepton Photon ‘07, Daegu
% 0.281) (0.309 y
K
rad ) (0.33 29.026.0
K
Measurements average (bckup) Combination, no CPV sum of likelihood curves, non-Gaussian shapes accounted
y
HFAG charm, http://www.slac.stanford.edu/xorg/hfag/charm/index.html
B. Golob, Belle D0 Mixing 50 Lepton Photon ‘07, Daegu
x
D0 → K+ -
x’2
y’
CPV: AD = (-0.76 ± 3.10)%
Measurements average (bckup)
HFAG charm, http://www.slac.stanford.edu/xorg/hfag/charm/index.html
B. Golob, Belle D0 Mixing 51 Lepton Photon ‘07, Daegu
20.023.0 0.88 |q/p|
rad ) (-0.09 19.017.0
Combination, CPV observables (A, x, ...) → |q/p|, , AD, x, y, RD, K
2 minimization, non-Gaussian shapes not accounted for
|q/p|
overall fit:2/ndf = 14.4 / 7
Measurements Combination
1996 FNAL E791 R M = (0.11 +0.30 −0.27 +0.00 −0.014 )%
2005 CLEO II.V R M = (0.16 ± 0.29 ± 0.29 )% 2004 BaBar R M = (0.23 ± 0.12 ± 0.04 )% 2005 Belle R M = (0.020 ± 0.047 ± 0.014 )
1999 FNAL E791 = (0.04 ± 0.14 ± 0.05 ) ps −1 (yCP = (0.8 ± 3.1)%)2000 FOCUS y CP = (3.42 ± 1.39 ± 0.74 )% 2002 CLEO II.V y CP = (−1.2 ± 2.5 ± 1.4 )% 2003 BaBar y CP = (0.8 ± 0.4 +0.5 −0.4 )% 2002 Belle y CP = (−0.5 ± 1.0 +0.7 −0.8 )% 2007 Belle y CP = (1.31 ± 0.32 ± 0.25 )%
2006 Belle x' 2 = (0.018 +0.021 −0.023 )% y' = (0.06 +0.40 −0.39 )%2007 BaBar x' 2 = (−0.022 ± 0.030 ± 0.021)% y' = (0.97 ± 0.44 ± 0.31)%
2006 BaBar K + π − π 0 RM = (0.023 +0.018 −0.014 ± 0.004)%2006 BaBar K + π − π+ π− RM = (0.019 +0.016 −0.015 ± 0.002)%
2005/2007 CLEO II.V x = (1.9 +3.2 −3.3 ± 0.4 ± 0.4)% y = (−1.4 ± 2.4 ± 0.8 ± 0.4)%2007 Belle x = (0.80 ± 0.29 ± 0.17)% y = (0.33 ± 0.24 ± 0.15)%
2006 CLEO-c RM = (0.17 ± 0.15)% y = (−5.8 ± 6.6)% cos δK π = 1.09 ± 0.66
RM semil.
yCP
x’2, y’
RM Kn
x, y
Cleo-c
B. Golob, Belle D0 Mixing 52 Lepton Photon ‘07, Daegu
Measurements average
Average
fit to individual measurements with x, y, free
assumingGaussianp.d.f.’s;
correlation forK+-;
illustration!
B. Golob, Belle D0 Mixing 53 Lepton Photon ‘07, Daegu
Prospects bckup
Combination numbers very preliminary
(yCP) ~ 0.15%, (A/yCP) ~ 0.10
(x) ~ (y) ~ 0.15%, (|q/p|) ~ () ~ 0.10
(x’2) ~ 0.12x10-3, (y’) ~ 0.20%
(x) ~ (y) ~ 0.10%(cos ) ~ 0.07(|q/p|) ~ 0.09, () ~0.05 rad
D0 → K+K- / +-
D0 → KS+-
D0 → K+-
combined
approximate projections to 5 ab-1
B. Golob, Belle D0 Mixing 54 Lepton Photon ‘07, Daegu