Post on 02-Apr-2015
B. Golob, Belle Charm physics at Belle 1 Belle Rev. Comm. 2007
B. GolobUniversity of Ljubljana
Belle Collaboration
Outline1. Introduction
2. Spectroscopy
3. Semileptonic D decays
4. D0 - D0 Mixing
5. Summary
Charm Physics at Belle
B-factory, c-factory
Introduction
B. Golob, Belle Charm physics at Belle 2 Belle Rev. Comm. 2007
√s = M((4S))c2=10.58 GeV
(B B) 1.1 nb (~750·106 BB pairs)
(c c) 1.3 nb (~850·106 XcYc pairs)
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) - measurements of known and new charmed baryons and mesons - measurements of new “exotic” states - understanding of charmonia production and decay - charm fragmentation - D0 mixing and CPV experimental tests of theor. predictions (most notably of (L)QCD); improve precision of CKM measurements (B physics); - meson decay constants and form factors - confrontation of spectroscopic results and predictions - charm branching fractions
c(2880)
c(2940)
c(2765)
1st observ.signnce > 6
New c-baryons
Spectroscopy
B. Golob, Belle Charm physics at Belle 3 Belle Rev. Comm. 2007
c → c+ K- +;
neutral states also observed, iso-doublet
Charm mesons and baryons laboratory to test predictions of quark model(s), HQS, Skyrme model, Regge trajectories, ....
PRL97, 162001 (2006) 460 fb-1
405 ± 50 evtssignificance 5.7
326 ± 40 evtssignificance 9.2
State Mass [MeV/c2] Width [MeV/c2]
c(2980)+ 2978.5±2.1±2.0 43.5±7.5±7.0
c(3080)+ 3076.7±0.9±0.5 6.2±1.2±0.8
confirmed by BaBar, hep-ex/0607042
hep-ex/0608043, 553 fb-1, subm. to PRL
c(2880) → c(2455) c+- with M(c±) ~ M(c(2455))
JP of c(2880) and c(2940) → c(2455) BaBar, PRL98, 012001 (2007), 287 fb-1
New c-baryons
Spectroscopy
B. Golob, Belle Charm physics at Belle 4 Belle Rev. Comm. 2007
c(2880)→ c(2455) angular distribution
J=1/2
J=3/2
J=5/2
c(2455)
c*
JP=5/2+ strongly favored
hep-ex/0608043, 553 fb-1, subm. to PRL
prospects (1 ab-1)
)%5.22.65.22())2455()2880((
))2520()2880(( *
cc
cc
c(2880)→ c(2455/2520) → ±4.5%;- c(2940) → c(2455) yield ~450, ang. analysis JP;- c (2980)0→ c
+ KS -
sign. → ~ 3 ; confirmation in other decay modes;goal: well established ensemble of hadrons with determined quan. num., to be confronted to theory A. Selem, F. Wilczek, hep-ph/0602128
deviations from linear Regge traj.
& n
ew s
tate
s!
Double cc production
Spectroscopy
B. Golob, Belle Charm physics at Belle 5 Belle Rev. Comm. 2007
J/
X
e- e+
PRL98, 082001 (2007) 350 fb-1
recoil method2
/2
/ )( JJcmsrec pEEM
266±63 evts
M=3943±6±6 MeV/c2
<52 MeV @90% C.L.
c1’ (23P1), c’’ (31S0)?
prospects (1 ab-1) recoil method: “factory” of cc with C=+1;
3 sensitivity min(e+e- →J/X) ~ 5-10 fb ((J/c) = 25 fb)
Spectroscopy
B. Golob, Belle Charm physics at Belle 6 Belle Rev. Comm. 2007
“Exotic” statesno obvious predicted candidates;most prominent X(3872);DD* molecule?number of results, recently:B → (D0 D0 0)K
PRL97, 162002 (2006), 414 fb-1
24.1 ± 6.1 evts 6.4
M=(3875.2 ± 0.7 ± 0.31.6 ± 0.8) MeV/c2
confirmed by BaBar, P. Grenier, 42nd Moriond QCD (2007), 347 fb-1
PRL91, 262001 (2003) 152M BB
B → X(→D0 D0 0) Kif enhancement X(3872)
1.36.3
000
8.8)/(
)(
JXBr
DDXBr
large mixing between c1’ and X(3872)?
other measurements: JPC=1++, 2-+;J=2: supressed decay to DD*, JPC=1++?
hard to accommodate in molecularmodel (~0.08) E.S.Swanson,
Phys.Rept. 429, 243 (2006)
2.5 diff. with X → J/
Spectroscopy
B. Golob, Belle Charm physics at Belle 7 Belle Rev. Comm. 2007
“Exotic” statese+e- → Y(→J/ ) ISR
BaBar, PRL95, 142001 (2005), 233 fb-1
hep-ex/0612006, 553 fb-1
165 +25-33 evts
sign.: 11
M=(4295 ± 10 ± 103 ) MeV/c2
=(133 ± 26 ± 136 ) MeV
2.5 difference with M from BaBar
Y(4260)
D*+D*-
D*+D-
s =
Exclusive (e+e- → D*D(*))
using ISR; partial recon., (Mrec)=1 MeV Mrec= Mrec(D(*)+ ISR) - Mrec(D(*)+ - ISR); data to help understand Y(4260) nature; coupled channels effects (Ds*Ds*, DD1
thresholds), hybrid state (decays to DD1, M?)
M.B. Voloshin, hep-ph/0602233 S.L. Zhu, PLB625, 212 (2005)
PRL98, 092001 (2007), 550 fb-1
in agreement with Cleo-c scans < 4.25 GeV
Spectroscopy
B. Golob, Belle Charm physics at Belle 8 Belle Rev. Comm. 2007
c(2800)
c(2980)
c(3077)
c(2880) hep-ex/0608043
PRL97, 162001
PRL97, 162001
PRL94, 122002
DsJ(2715) hep-ex/0608031
List
X(3872)
X(3940)
Y(3940)
Z(3930)
Y(4260)
hep-ex/0505037
hep-ex/0505038
PRL91, 262001
PRL97, 162021
PRL98, 082001
PRL94, 182002
PRL96, 082003
hep-ex/0612006
prospects (1 ab-1)
X(3872): new results B →XK to test models Br(B0 →KSX)/Br(B+ →K+X) ~ ±15% molecular model: 6-29% M(Xh)-M(Xl) ~ ±1 MeV tetra-q model: 8 ±3 MeV
Y(4260): data to help interpretation combining e+e- → Y(→J/ ) ISR and (e+e- → D(*)D(*)); M ~ ±10 MeV/c2; enough to distinguish from thresholds? min ~ ±15% in each mode
e.g. F.E. Close, P.R. Page, PLB578, 119 (2004)
L. Maiani et al., PRD71, 014028 (2005)
Semileptonic D decays
B. Golob, Belle Charm physics at Belle 9 Belle Rev. Comm. 2007
D0 semileptonic decays determination of form factor; test of LQCD to ±5%;
e+e- → Dtag(*)Dsig*;
inverse reconstruction; start from Dtag
(*) and CMS momentum recoil momentum;
method enables: - good q2 resolution ((q2)~0.0145 GeV2/c2) - absolute normalization (inclusive D0 signal)
signal: p2()=0;
3223
2
2
0
3223
2
2
0
)(24
||)(
)(24
||)(
pqfV
dq
Bd
pqfV
dq
Dd
Bub
Dcd
PRL97, 061804 (2006), 282 fb-1
|Vub| from B0 → l : ±14% from f.f., ±3% from Br
D0 → N=106±12
D0 → e N=126±12
m2 [GeV2]
fake-D0 bkgdata
hadronic bkgdata
Kl bkgdata
l bkgMC
current lumin.
expected accuracy
D0 → K l
D0 → l
Semileptonic D decays
B. Golob, Belle Charm physics at Belle 10 Belle Rev. Comm. 2007
D0 semileptonic decays competitive (K) l Br measurement;
PRL97, 061804 (2006), 282 fb-1
Y. Gao (Cleo-c), ICHEP06, 281 pb-1
first direct Br(D0 → ) determination;
comparison to LQCD;
f+D(0) = 0.624 ± 0.020 ± 0.030
unquenched: C. Aubin et al., PRL94, 011601 (2005)f+
D(0) = 0.64 ± 0.03 ± 0.05
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 11 Belle Rev. Comm. 2007
Mixing phenomena
well known in K0, Bd0 and Bs
0 system (last year); eluded observation so far in the D0 system;
c
u
u
c
d, s, b d, s, b
W+
W-
D0 D0
Vci*
Vcj
Vuj*
Vui
002,1 DqDpD
2
; 2121 ymm
x
d-like quarks exchanged;effective GIM suppression;
D0 decays: CF; mixing: DCS;x, y ~ sin2C (SU(3) breaking)
difficult to calculate;x, y affect the t distribution of D0, observables;largest predictions in SM: |x|, |y| 10-2
I.I. Bigi, N. Uraltsev, Nucl. Phys. B592, 92 (2001);A.F. Falk et al., PRD69, 114021 (2004)
CPV in D0 system:first two generations involved;Wolfenstein param., (Vcs)=A24 ~ O(10-3)
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 12 Belle Rev. Comm. 2007
D0 → KS +- t-dependent Dalitz analysis different decays (CF, DCS, CP eigenstates) identified through Dalitz analysis; their relative phases determined;
titititi eemmp
qeemm
tDftmm
2121 ),(2
1),(
2
1
)(),,(
2222
022
AA
M
MMAA ,1p
q
arXiv: 0704.1000
no CPV
< f | D0 > < f | D0 > 1,2=f(x,y);
analogous for M = < f | D0(t) >
fit M(m-2,m+
2,t) to data distribution x, y
Two recent Belle measurements - decays to CP final state, D0 → K+K-/+-
- decays to hadronic multi-body final state, D0 → KS +-
common:D*+ →D0s
+
p*(D*) > 2.5 GeV/c
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 13 Belle Rev. Comm. 2007
D0 → KS +-
arXiv: 0704.1000
signal in M(KS +- ) and
Q= M(KS +-s)- M(KS +-)- M()
M Q signalrnd slow combin.
(534.4±0.8)x103 evts
Dalitz model: 13 BW resonances, non-resonant contr.;
test of S-wave contr.: K-matrix formalism
K*(892)- K*(892)+
K*X(1400)+
Results (fit fractions, phases) in agreement with (measurement of 3)
PRD73, 112009 (2006)
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 14 Belle Rev. Comm. 2007
D0 → KS +-
arXiv: 0704.1000
t [fs]
x = 0.80±0.29±0.17 %y = 0.33±0.24±0.15 %
= 409.9±0.9 fs
most sensitive meas. 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
t-projection
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 15 Belle Rev. Comm. 2007
D0 → K+K- / +-
hep-ex/0703036v2
CP even final state;t distribution not pure exponential (D1 and D2 contr.);
treated as exponential changed effective
y
xAyKK
Ky
CPVno
MCP
sin
2
1cos1
)(
)(
S. Bergman et al., PLB486, 418 (2000)
AM, : CPV in mixing and interference;
CPV: D0 → f and D0 → f decay rates different; effective different
sideband
K+K- K-+ +-
Nsig 111x103 1.22x106 49x103
P 98% 99% 92%
sincos2
1
)()(
)()(00
00
xyA
KKDKKD
KKDKKDA
M
M, Q, t selection optimized in MC
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 16 Belle Rev. Comm. 2007
D0 → K+K- / +-
hep-ex/0703036v2
simultaneous binned likelihood fit to K+K- /K-+/+- decay-t
)(')'(/' tBdttteN
dt
dN t R
R : ideally each i Gaussian resol. term with fraction fi;pulls: described by 3 Gaussians
N
i kikki tsttGwftt
1
3
10 ),,'()'( R
2/ndf=1.084 (ndf=289)
= 408.7±0.6 fs
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 17 Belle Rev. Comm. 2007
D0 → K+K- / +-
hep-ex/0703036v2
results yCP = (1.31 ± 0.32 ± 0.25) %
evidence for D0 mixing(regardless of possible CPV)
3.2 from zero (4.1 stat. only)
K+K-/+-
and K-+ratio
search for CPV:
A = (0.01 ± 0.30 ± 0.15) %difference of lifetimesvisually observable
KS +- : (x,y)=(0,0) has C.L. 2.6%
K+K- / +-: y=0 has C.L. 6x10-4
D0 - D0 Mixing
B. Golob, Belle Charm physics at Belle 18 Belle Rev. Comm. 2007
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;
preliminary study in KS+-: (|q/p| 1 + AM/2) ~ 0.30, () ~ 17o
K+K- / +-: (A/yCP AM/2 - x/y tan) ~ 0.25
combination at 1 ab-1:
(x) ~ ±0.21%(y) ~ ±0.17%
() ~ 9o, (|q/p|) ~ 0.15
Summary
B. Golob, Belle Charm physics at Belle 19 Belle Rev. Comm. 2007
Belle great exp. environment for charm studies; complementary to c-factories;
In several areas exp. results ahead of theor. predictions in accuracy
Spectroscopic results: conventional states - confrontation with predictions; “exotic” states - new challenge; all - quantum number determ.
(Semi)leptonic D meson decays: tests of non-pert. QCD
First evidence for D0 mixing: more precise determ. of parameters and search for CPV
Spectroscopy, c, bckup
c → c+ K- +;
no reflections in c+ K+ -
Wrong sign charge comb.: c+ K+ -;
possible reflections from c*+ → c
+ + - with misidentified as K would appear here
PRL97, 162001 (2006) 460 fb-1
s s
c+
u
c
d
d
c
u
u
+
K-
u
c+ K-
p
+
67 ± 20 evtssignificance 4.4
neutral states also observed, iso-doublet
State Mass [MeV/c2] Width [MeV/c2]
c(2980)+ 2978.5±2.1±2.0 43.5±7.5±7.0
c(3080)+ 3076.7±0.9±0.5 6.2±1.2±0.8
c(3080)0 3082.8±1.8±1.5 5.2±3.1±1.8
B. Golob, Belle Charm physics at Belle 20 Belle Rev. Comm. 2007
Spectroscopy, c, bckup
c → c+ K- +;
BaBar: 2-D fits in M(cK) and M(c)
hep-ex/0607042
B. Golob, Belle Charm physics at Belle 21 Belle Rev. Comm. 2007
cKnon-res.
Spectroscopy, c, bckup
c → c+ K- +;
new states; Belle discoveries and measurem.
J.L. Rosner, hep-ph/0609195
B. Golob, Belle Charm physics at Belle 22 Belle Rev. Comm. 2007
c
high mass L=2?
Sl = 0 (lightestorbital excit.)JP = 5/2+, 3/2+
5/2+ → c F-wave3/2+ → c P-wave
Spectroscopy, c, bckupBelle, hep-ex/0608043, 553 fb-1, subm. to PRL
c(2455)
c*
J=1/2
J=3/2
J=5/2
2/ndf = 49.9/9 (J=1/2) 36.0/8 (J=3/2) 10.8/7 (J=5/2)
angular analysis
repeat fit in bins of
J=5/2 strongly favored
c(2880) JP
B. Golob, Belle Charm physics at Belle 23 Belle Rev. Comm. 2007
Spectroscopy, c, bckupBelle, hep-ex/0608043, 553 fb-1, subm. to PRL
c(2880)→c(2455)
c(2880)→c(2520)
c(2880)→c
c(2880) JP
repeat fit in bins of M(c±) c(2880)) vs M(c±)
c(2880) P interpretation
HQS: 5/2+ sl l 2+ 3+
c*/c 0.24 0.37
5/2- sl l 2- 3-
c*/c 1.46 0.12M(2880)=2881.2±0.2±0.4 MeV
B. Golob, Belle Charm physics at Belle 24 Belle Rev. Comm. 2007
N. Isgur, M.B. Wise, PRL66, 1130 (1991)
S. Capstick, N.Isgur, PRD34, 2809 (1986)
Spectroscopy, c, bckupBelle, hep-ex/0608043, 553 fb-1, subm. to PRL
comparison of two charged states;
reflections from c(2980, 3077) → c
+K-+ with K- misid.
appear in c++ -
but not in c0 +
c(2880) JP
B. Golob, Belle Charm physics at Belle 25 Belle Rev. Comm. 2007
c++ -
c0 +
Spectroscopy, 2cc, bckup
B. Golob, Belle Charm physics at Belle 26 Belle Rev. Comm. 2007
Double cc production(e+e-→J/X)(fb) exp. LO NLOc 25.6±2.8±3.4 3.78±1.26 18.9
c0 6.4±1.7±1.0 2.40±1.02
c(2S) 16.5±3.0±2.4 1.57±0.52
22S
24S
Belle, PRD70, 071102 (2004)
E. Braaten, J. Lee, PRD67,054007 (2003)
Y. Zhang et al., PRL96 ,092001 (2006)
PRL98, 082001 (2007) 350 fb-1
Spectroscopy, 2cc, bckup
B. Golob, Belle Charm physics at Belle 27 Belle Rev. Comm. 2007
Double cc production
C() = -1
C(J) = -1C(X) = +1
C() = -1
C(X) = -1
X(3940)→D(*)D ?reconstruct J/ + one DMrec(J/D) ~ M(D(*))
constrain Mrec(J/D)=M(D(*))(Mrec(J/))~10 MeV/c2
Mrec(J/D)=M(D)
Mrec(J/D)=M(D*)24.5±6.9evts5
no evidence forX(3940)→J/ X(3940)≠Y(3940)
inclusive/D*D tagged sample,common evts removed
B>2(X→D*D) > 45% @90% C.L.B(X→D D) < 41% @90% C.L.B(X→J/) < 26% @90% C.L.
PRL98, 082001 (2007) 350 fb-1
Spectroscopy, 2cc, bckup
B. Golob, Belle Charm physics at Belle 28 Belle Rev. Comm. 2007
Double cc production
X(3940)=c1’?
DD* mode dominantno c1 in Mrec,
X(3940)=c’’?
expected mass 4040-4060 MeV/c2
PRL98, 082001 (2007) 350 fb-1
Spectroscopy, DsJ, bckup
B. Golob, Belle Charm physics at Belle 29 Belle Rev. Comm. 2007
B+ → D0D0K+
hep-ex/0608031 414 fb-1
fit to E, Mbc
in bins of M(D0K)
J=-1?
Spectroscopy, X, bckup
Possible JPC
C parity B±,0 → K±,0 X (→ J/) 13.6 ± 4.4 evts.(4)
mode with substantial Br
B±,0 → K±,0 c1 (→ J/)serves for calibration of width
hep-ex/0505037, 275M BB
C(X(3872))=C()·C(J/)=+1
05.014.0)/(
)/(
JXBr
JXBrconfirmed by BaBar, PRD74, 071101 (2006), 260 fb-1
B. Golob, Belle Charm physics at Belle 30 Belle Rev. Comm. 2007
Spectroscopy, X, bckup
0-+, 1--, 1+-, 0++, 1++, 2++, 2-+, 2--, 3--
Angular distributions
B±,0 → K±,0 X (→ +- J/)(only examples shown)
-
l+ l-
X(J/)+
|cos()|
2/ndf=31/9 JPC=0++
JPC=1++
|cos()|
-
+
K B
X(J/)
2/ndf=5/9
in the limit where X, J/rest frames coincidedN/d(cos()) sin2()
relative motion of frames included in MC
cc JPC
hep-ex/0505038, 275M BB
B. Golob, Belle Charm physics at Belle 31 Belle Rev. Comm. 2007
Spectroscopy, X, bckup
B. Golob, Belle Charm physics at Belle 32 Belle Rev. Comm. 2007
B → (D0 D*0)K BaBar: D*0 → D0 0 / D0
BaBar, P. Grenier, 42nd Moriond QCD (2007), 347 fb-1
Spectroscopy, Y, bckup
Coupled channels
threshold DD1, 4285 MeV/c2
M(Y)=4295 MeV/c2
parameterization acc. to
Y(4260)
M(D)+M(D1) E [GeV]
(e+e- → D*D*)
arb.
uni
ts
4265 GeVM.B. Voloshin, hep-ph/0602233
B. Golob, Belle Charm physics at Belle 33 Belle Rev. Comm. 2007
hep-ex/0607083
Exclusive (e+e- → DD) BaBar
Semileptonic D decays, bckup
D0 semileptonic decays determination of form factor, test of LQCD;
e+e- → Dtag(*)Dsig*;
inverse reconstruction: Dtag
(*) fully reconst. K n, n=1,2,3; p(Dtag), p(e+e-), p(primary , K) p(Dsig*); +
slow from Dsig*+ →D0 +slow
p(D0sig);
and l p();
PRL97, 061804 (2006), 282 fb-1
D
e+ e-
D
e/µ
D* D*
tag signal
K
K
K
primary mesons
D0 → K eD0 → K N=1318±37N=1249±37
K l signal
m2 [GeV2]
B. Golob, Belle Charm physics at Belle 34 Belle Rev. Comm. 2007
Semileptonic D decays, bckup
D0 semileptonic decays determination of form factor, test of LQCD;
PRL97, 061804 (2006), 282 fb-1
D0 → e
Y. Gao (Cleo-c), ICHEP06, 281 pb-1
f+D(0) = 0.624 ± 0.020 ± 0.030
f+D(0) = 0.670 ± 0.028 ± 0.011 ± 0.009
Br results:
B. Golob, Belle Charm physics at Belle 35 Belle Rev. Comm. 2007
Semileptonic D decays, bckup
D0 semileptonic decays background
fake D0: from WS sample (Dtag, Dsig same flavor);
Kl (in l ): from measured Kl with independently measured fake rate;
hadronic (misid as l): sample with charge of l opposite to the s from D*sig (OS sample); contains no signal and no semil. background;
use K and intentionally misid-ed as l; fit the OS sample amount of and K misid-ed background
PRL97, 061804 (2006), 282 fb-1
B. Golob, Belle Charm physics at Belle 36 Belle Rev. Comm. 2007
D0 - D0 Mixing, KS+-, bckup
B. Golob, Belle Charm physics at Belle 37 Belle Rev. Comm. 2007
D0 → KS+-
Dalitz results
arXiv: 0704.1000
D0 - D0 Mixing, KS+-, bckup
B. Golob, Belle Charm physics at Belle 38 Belle Rev. Comm. 2007
D0 → KS+-
systematics
arXiv: 0704.1000
D0 - D0 Mixing, KS+-, bckup
B. Golob, Belle Charm physics at Belle 39 Belle Rev. Comm. 2007
D0 → KS+-
systematics
arXiv: 0704.1000
Systematics (largest) model dependence [10-4]: x y +12.5 +5.0 variation of DCS/CF - 6.4 -4.4 ratios for K*'s
±7.3 ±5.8 K-matrix --------------------------------- +14.6 +7.8 Total model dep. -13.5 -8.5
t fit: x y +7.6 -7.8 p* variation -5.6 -5.7 Dalitz pdf for bkg. from different t bins ----------------------- +8.6 +7.9 Total t fit -6.7 -11.6
Total [10-4]: x y +17 +11 -16 -15
D0 - D0 Mixing, KS+-, bckup
B. Golob, Belle Charm physics at Belle 40 Belle Rev. Comm. 2007
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:
D0 - D0 Mixing, KS+-, bckup
B. Golob, Belle Charm physics at Belle 41 Belle Rev. Comm. 2007
D0 → KS+-
efficiency and resol. in M(
arXiv: 0704.1000
rnd s
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 ± 0.005
diff. w.r.t. fw=0.5 in systematic error
D0 - D0 Mixing, KS+-, bckup
B. Golob, Belle Charm physics at Belle 42 Belle Rev. Comm. 2007
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 [ (t) + Exp(t) ]R’(t)
D0 - D0 Mixing, K+K- / +-, bckup
B. Golob, Belle Charm physics at Belle 43 Belle Rev. Comm. 2007
M [GeV/c2]
D0 → K+K- / +-
hep-ex/0703036v2
D0 - D0 Mixing, K+K- / +-, bckup
B. Golob, Belle Charm physics at Belle 44 Belle Rev. Comm. 2007
D0 → K+K- / +-
systematics
hep-ex/0703036v2
D0 - D0 Mixing, K+K- / +-, bckup
B. Golob, Belle Charm physics at Belle 45 Belle Rev. Comm. 2007
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
D0 - D0 Mixing, K+K- / +-, bckup
B. Golob, Belle Charm physics at Belle 46 Belle Rev. Comm. 2007
D0 → K+K- / +-
fitted t0 of R in diff. run periods and diff. decay modes
hep-ex/0703036v2
D0 - D0 Mixing, K+K- / +-, bckup
B. Golob, Belle Charm physics at Belle 47 Belle Rev. Comm. 2007
D0 → K+K- / +-
equal t0 assumption
yCP=t0CP - t0
K / K
from MC cocktail, includingrunning periodswith slight misalign.of SVD
hep-ex/0703036v2
D0 - D0 Mixing, K+K- / +-, bckup
B. Golob, Belle Charm physics at Belle 48 Belle Rev. Comm. 2007
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
D0 - D0 Mixing, prosp., bckup
B. Golob, Belle Charm physics at Belle 49 Belle Rev. Comm. 2007
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