a. bay lphe epf lausanne1 summary b factories and lhcb
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A. Bay LPHE EPF Lausanne 1
Summary
B factories and LHCb
A. Bay LPHE EPF Lausanne 2
CP & T violation only in K0 system ???
Since 1964, CP and or T violation was searched for in othersystems than K0, other particles decays, EDM...
No other signal until 2001...
A. Bay LPHE EPF Lausanne 3
production of(4s) (10.58GeV/c2) = 0.425(4s) B0 B0
B+ B
BaBar (SLAC) and Belle (KEK)
in 2001: observation of CP violation in the B mesonsystem, using "asymmetric collider" B factories.KEKB machine:
8 GeVelectrons
3.5GeV positron
A. Bay LPHE EPF Lausanne 4
KEKB24% Y(4s)76% continuum
year 2003: crossing the(psychological) luminositybarrier of 1034 cm-2s-1
1.5807 1034
on 18-May-2005
A. Bay LPHE EPF Lausanne 5
Pea
k lu
min
osit
y cm
s
Luminosity trend in the last
30 years
A. Bay LPHE EPF Lausanne 6
BaBar and Belle
Study of the time dependent asymmetry in decay rates ofB0 and anti-B0
m = mass difference of "mass eigenstates" ~ 0.49 1012 h/s
€
ACP(t) =N(B 0 → J /Ψ KS) − N(B0 → J /Ψ KS)
+(t) = S sin Δm t( )
CP violated S ≠ 0
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CP measurements at B factories
Difficult: B0 mean life 1.54 10 s. Lorentz boost very small.B factories are asymmetric: the c.m. is moving.The two B decay at different position ~ on the z axis.We measure de difference z of the 2 vertices. r is small.
Δz cβγΔt ~ 200 m at Belle
(4s)
zz1 z2
z
J/Ks
e
Dr
A. Bay LPHE EPF Lausanne 8
CP measurements at B factories
(4s)
zz1 z2
z
J/Ks
fCP
B0 and anti-B0 oscillate coherently (QM entangled state).When the first decays, the other is known to be of the oppositeflavour use the other side to infer the flavour, B0 or anti-B0,of the fCP parent
e
D
€
e+ → B0
e− → B 0 ⎧ ⎨ ⎩
region of B0 & B0
coherentevolution
A. Bay LPHE EPF Lausanne 9
Belle experiment
Central Drift Chamber He/C2H5(Pt/Pt)2=(0.0019 Pt)2+(0.0030)2
CsI(Tl) 16X0
E/E ~ 1.8% @1GeV
Aerogel Cherenkov n=1.015~1.030
Si Vertex detector3 layers mid 2003now 4 layers Impact parameter resolution 55m for p=1GeV/c
TOF counter
SC solenoid 1.5T
8GeV e
3.5GeV e
Started in 1999~300 physicists from ~60 institutes in14 countries.
/ KL detection 14/15 layers of RPC+Fe : efficiency > 90%<2% fake at p > 1GeV/c
Particle ID : dE/dx in CDC dE/dx =6.9% TOF TOF = 95ps Aerogel Cerenkov ACC Efficiency = ~90%, Fake rate = ~6% 3.5GeV/c
A. Bay LPHE EPF Lausanne 10
Belle
ACC
Silicon Vertex Detector SVD Impact parameter resolution 55m for p=1GeV/c at normal incidenceCentral Drift Chamber CDC (Pt/Pt)2 = (0.0019 Pt)2 + (0.0030)2 K/ separation : dE/dx in CDC dE/dx =6.9% TOF TOF = 95ps Aerogel Cerenkov ACC Efficiency = ~90%, Fake rate = ~6% 3.5GeV/c, e : CsI crystals ECL E/E ~ 1.8% @ E=1GeV e : efficiency > 90% ~0.3% fake for p > 1GeV/cKL and : KLM (RPC) : efficiency > 90% <2% fake at p > 1GeV/c
~ 8 m
€
Ldt ≈∫ 400 fb
4 108 B pairs
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spatial resolution for Blepton + Xz (lepton) ~ 100 m
Belle micro-vertex detector
A. Bay LPHE EPF Lausanne 12
Belle event
A. Bay LPHE EPF Lausanne 13
Particle ID in Belle
Particle ID uses information fromACC, TOF, dE/dx( CDC)
€
Prob to be a K{ } =L(K)
L(π) + L(K)
Barrel ACC
Endcap ACC
dE/dx
TOF
p (GeV/c)
cut
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Experimental program: measure sides and anglesof the CKM matrix
* CP violated in the SM => the area of triangle 0* Any inconsistency could be a signal of the existence of phenomena not included in the SM
~Vub ~Vtd
~Vcb
€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
Use B mesonsphenomenology
t quark
oscillations
CP asymmetries
b quark
decays
A. Bay LPHE EPF Lausanne 15
Analysis and results
•Continuum rejection•Kinematics at the Y(4s)
•The Unitary triangle: determination of Vub
" Vcb" Vtd" " "
•No time for other topics
~Vub ~Vtd
~Vcb
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Continuum rejection24% Y(4s)76% continuumfrom event topology which
is ~spherical for BB, jet like for continuumand angular distributions
BB
Build Likelihood L for B and qq hypothesisusing event shape variables and cos B
0 0.2 0.4 0.6 0.8 1
€
LB
LB + L qq
cut
A. Bay LPHE EPF Lausanne 17
How to find a B meson?Kinematics variables at the Y(4S)
Mbc
5.2 5.24 5.28 GeV/c2
0
E0.2
0.2
GeV/c2
€
Mbc = (E beam* )2 −
r p B
* 2
€
E = EB* − E beam
*
Gather candidates Band calculate (pB,EB).Boost to c.m. (pB
*,EB*)
"beam constrained mass"
€
Ebeam* ≡
s
2
Example:B D0
with
A. Bay LPHE EPF Lausanne 18
Determination of Vcb
€
l −
W
b c
Vcb
World Average: |Vcb| (inclusive) (42.0 0.6 0.8) 10-3
|Vcb| (exclusive) (40.2 +2.1 ) 10-3
-1.8
€
Vcb = (40.2 ±1.9)10−3
D0
€
dΓ
dy=
GF
2
48π 3MD*
3 MB 0 − MD*( )
2g(y)Vcb
2F(y)2
g(y) known function of y
€
B 0 → D*+e−ν e
d
D*+B0
q
F(y) hadronic form factor
plus ~5% error on F(1)
A. Bay LPHE EPF Lausanne 19
Determination of Vub
€
l
W
b u
Vub
bc
bu
0 1 2 3 GeV/cLepton momentum
(in c.m.)
Exemple: use lepton momentum distributionfrom inclusive semileptonic decays
€
B → Xul ν
Less than 10% of thespectrum background free
hep-ex/0305037, with reconstruction
|Vub| (10-3) = 3.96 0.17(stat) 0.44(syst) 0.29(theo) 0.34(bc) 0.26(bu)
Average(inclusive) Vub=(4.12±0.13±0.60)10-3
A. Bay LPHE EPF Lausanne 20
Determination of Vtd
B0 B0
t
d
b
tW W
b
d
Vtd
0 3 6 9 ps
Probability1
B0
B0
Starting from a pure sampleof B0, for instance,a B0 component builds upin a time scale of a few ps:
€
P(B0)∝ e−t /τ 1+ cos Δmd t( )[ ]
P(B 0)∝ e−t /τ 1− cos Δmd t( )[ ]
measure oscillation frequency
€
Vtd ∝ Δmd
A. Bay LPHE EPF Lausanne 21
region of B0 & B0
coherentevolution
md with di-lepton events
* KEK-B boost <Δz> cβγ ~ 200 m
(4s)
zz1 z2
z
e+
* Tag B flavour from semileptonic B0 X l B0 X l
X
Y
* B0 and B0 oscillate coherently (QM entangled state).When the first decays, the other is known to be of the oppositeflavour.
t ~ z/c
A. Bay LPHE EPF Lausanne 22
md from di-lepton events .2
-12 -8 -4 0 GeV2
NMissing mass
Background: B+ X l B X l
Selection strategy of the "soft pion tag"B0 D* l Br3%
D0 Br70%
Event selection:- 1st lepton P*> 1.8 GeV- 1 pion of opposite sign P* < 1 GeV- 2nd lepton P*> 1.3 GeV- cut on M
2
(Frederic Ronga, PhD thesis, 2003)
A. Bay LPHE EPF Lausanne 23
md from di-lepton events .3
Get z distributionsfor "Same Sign"and "Opposite Sign"leptons couplesand fit for md...
OSSS
J/ l+ l toinfer resolution
-2 -1 0 1 2 z (mm)
SS
-2 -1 0 1 2 z (mm)
OS
0 1 2 z (mm)
€
Asymmetry(t) =OS −SS
OS + SS(t)
A. Bay LPHE EPF Lausanne 24
F. Ronga
average
md and Vtd HEP-PH/0206171
€
Vtd ∝ Δmd fB BB
Bagparameter
B decayconstant
|Vtd | ~ (8±2)10-3
~20% error !
{
A. Bay LPHE EPF Lausanne 25
UT sides
The UnitaryTriangle
inferred from its sides
and fromK0 data
Vub/Vcb
From K0
md & ms
10
Excluded area has <0.05 CL
A. Bay LPHE EPF Lausanne 26
from B0 J/ Ks
b
dB0
Vcb
cc
sKs
J/
d
B0
Vcbc
sKs
J/
Vtd
Vtb
VtdVtb
c
b
Interference between the 2 amplitudes gives a "time-dependent CPV"
€
AsymCP (t) =N(B 0 → J /Ψ KS ) − N(B0 → J /Ψ KS )
N(B 0 → J /Ψ KS ) + N(B0 → J /Ψ KS )(t)∝ SCP sin Δmd t( )
CKM phase 0 !
CKM phase = 0
sin2
}
SM:
B0
d
Golden ChannelGolden Channel
A. Bay LPHE EPF Lausanne 27
Any "direct" CP violation ?
b
dB0
Vcb
cc
sKs
J/
dB0
Vtb c
K
s
J/c
b
s
No "direct CPV" expected in SM in B J/ Ks, but who knows ?...
CKM phase = 0
CKM phase = 0
t
Vts
€
AsymCP (t) =N (B
0→ J / Ψ KS ) − N (B
0→ J / Ψ KS )
+(t)∝ ACP cos Δmd t( ) + SCP sin Δmd t( )
sin2
}
SM:
}
0
A. Bay LPHE EPF Lausanne 28
Time dependent asymmetry measurement
(4s)
zz1 z2
z
J/Ks
fCP
e
D
€
e+ → B0
e− → B 0 ⎧ ⎨ ⎩
region of B0 & B0
coherentevolution
€
ACP (t) =N (B
0→ J / Ψ KS ) − N (B
0→ J / Ψ KS )
N (B 0
→ J / Ψ KS ) + N (B0
→ J / Ψ KS
(t)
Need to "tag" the flavour: B0 or B0.B0 and B0 oscillate coherently (QM entangled state) use the other side to infer the flavour
t ~ z/c
ftag
A. Bay LPHE EPF Lausanne 29
b ccs reconstruction
140 fb1, 152M BB pairs
B 0 J/KL
b ccs (J/KL excluded)
5417 events are used in the fit.pB GeV/c
A. Bay LPHE EPF Lausanne 30
A large CP asymmetry has been observed!
World average (October 2005): SCP = 0.726 ± 0.037
J/KL
ACP~ 0, compatible with no direct CPV
SM: SCP = sin(2) => or 66.3°)
J/KL is OK
€
AsymCP (t) =N (B
0→ J / Ψ KS ) − N (B
0→ J / Ψ KS )
+(t)∝ ACP cos Δmd t( ) + SCP sin Δmd t( )
A. Bay LPHE EPF Lausanne 31
SM & KM model is verified !
= 23.7°± 2.1° = 66.3°± 2.1°
A. Bay LPHE EPF Lausanne 32
UT with sin2
The UnitaryTriangle
fit including sides,
K0 data,and
sin2
A. Bay LPHE EPF Lausanne 33
b sss, a B0 Ks puzzle ?
b to s transition is second order
(gluonic penguin).Prediction from SM: ~
same value of sin(2) as in ccs because no additional
phase from the loop.
VtsV
tb*
B0
b
d
s
s
d Ks
s
W
t
??????
B0
b
d
s
s
d
s
squark
unless new physics entersthe loop. For instance:
A. Bay LPHE EPF Lausanne 34
B0 Ks .2
6811 signals106 candidates in the fitpurity = 0.640.10efficiency = 27.3%
B 0 KS
5.2 5.4 5.28 GeV/c2
€
SφKs = −0.96 ± 0.50−0.11+0.09
€
AφKs = −0.15 ± 0.29 ± 0.07
BaBar
€
SφKs = +0.45 ± 0.43± 0.07
Beam-Energy Constrained Masssin2(ccs)
A. Bay LPHE EPF Lausanne 35
from BD0K D0 Ks +-
See A.Giri, Yu.Grossman, A.Soffer, J.Zupan hep-ph/0303187
u
uB+
bc
s
D0
Ks+
-
K+
u
B+
c
s
D0
Ks+
-
b u
K+
€
A1 ~ VcbVus* ~ Aλ3
€
A2 ~ VubVcs* ~ Aλ3 ρ + iη( ) ~ exp iγ{ }
D0 and D0 decay to same final state mixed state is produced:
€
˜ D 0 = D 0 + ae iθ D0
€
˜ D 0 = D 0 + ae i(δ +γ ) D0
Dalitz's analysis with variables and
€
m2(Ks,π +)
€
m2(Ks,π −)
a, , unknown
A. Bay LPHE EPF Lausanne 36
from BD0K D0 Ks +- .2
0.5 1 1.5 2 2.5 3
3
2
1
€
m2(Ks,π +)
€
m2(Ks,π −)D0 Ks +- as a sum of 2 body decays
Fit Dalitz plot witha, , as free parameters
a = 0.33±0.10±0.03±0.03 = 162° +20
-25 ±12°±24° = 95° +25
-20 ±13°±10°
90%CL: 61°< < 142° preliminary
A. Bay LPHE EPF Lausanne 37
Belle:very, verypreliminary
A. Bay LPHE EPF Lausanne 38
from B0
€
Asym t( ) = Aππ cos Δmd t( ) + Sππ sin Δmd t( )
0Bd
bW
d
uud
+
A = 0S = sin(2+2)= sin(2)
without penguin contributions:
Isospin analysis needed for the extraction of .Need to measure also B0 B+
d
b
W
tg
d
uu
d
0B
+
-
This is not the case: large"penguin pollution" expected(but intrinsically interesting..!)
Consider B0 first:
A. Bay LPHE EPF Lausanne 39
B0
Phys Rev
from ~231 : A = +0.58 0.15 0.07 S = 1.00 ± 0.21 ± 0.07
charmless 3-body B decay
K
continuum
syst. primarily frombackground fraction
BABAR:
A = 0.30 ± 0.25 ± 0.04
S = .02 ± 0.34 ± 0.05
A0
hep-ex/0401029
A. Bay LPHE EPF Lausanne 40
B0
Belle
BaBardirectCVP
A. Bay LPHE EPF Lausanne 41
First signal from B0
Mbc [GeV/c2]
using 152 M BB: Br(B0 ) = (1.7 ± 0.6 ± 0.2)10-6
B+
continuum
BABAR: Br(B0 ) = (2.1 ± 0.6 ± 0.3)10-6
Phys. Rev. Lett. 91 (2003) 261801
(hep-ph/0306058 gives 74° < < 132°... )
A. Bay LPHE EPF Lausanne 42
Global fit of data from all sources
A. Bay LPHE EPF Lausanne 43
Test of SM in quark sector:check the triangle !
Does SM give a coherent picture of CP violation ?
Unitary triangle can be build using its sides
or the angles.
Other information comes form CPV with Kaons and B.
All the information must be consistent (else new physics ? or measurement error ? or bad supporting theory ?)
A. Bay LPHE EPF Lausanne 44
Test of SM in quark sector
Summer 2004
sin(2) = 0.726 ± 0.037 from J/K0
sin(2) = 0.734 ± 0.043 from sides
(68% and 95% CL contours)
from sides
Summer 2005
sin(2) = 0.687 ± 0.032 from J/K0
sin(2) = 0.793 ± 0.033 from sides 2.3
2005 test not sogood...
Compare unitarity triangle from CP-violating processes K CPV in K sector and sin(2) CPV in B sector
with unitarity triangle measured from the sides only i.e.from
CP-conserving processes
(|Vub| and md, ms)
A. Bay LPHE EPF Lausanne 45
Test of SM in quark sector .2
Measure unitarity triangle only from the angles in B decays: sin(2) from B0 (cc)K0 interference of bc amplitude with B0_B0 mixing (or +) from B , , interference of bu amplitude with B0 _B0 mixing from B D(*)K interference of bc and bu amplitudes
Test passed.
Compare again with trianglefrom (CP conserving) side measurements
A. Bay LPHE EPF Lausanne 46
sin(2) from bs penguin
Naive average of all bs modesdeviated from B(cc)K0 modesby 3.8 in 2003, now only 2.6
sin(2)eff=0.43±0.07to be comparedwith all charmoniumresult 0.726±0.036
A. Bay LPHE EPF Lausanne 47
Other topics (a few hep-ex)
• sin(2) from J/ hep-ex/0308053
• from BD* hep-ex/0308048
Rare B decays:•B hh {, K, KK, } hep-ex/0307077, hep-ex/0306007
•BKhh {K } hep-ex/0307082
•B pph, p hep-ex/0302024
•BK(*), K(*) K(*)ll hep-ex/0308044
•B K hep-ex/0305068
•B cp Phys. Rev . Lett. 90 (2003) 121802
CPV results:
EPR & Bell test of QM: hep-ex/0310192
Phys. Rev. Lett. 91 (2003) 262001New charmonium X(3871):
A. Bay LPHE EPF Lausanne 48
down strange beauty up 0.1% 1% 5%charm 2% 2% 3% top 5% 5% 29%
CKM matrix 2007
* Vij)/Vij ~€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
CDF + D0: 4 fb-1 eachBABAR + Belle: ~1000 fb-1
CLEO-C
(sin(2)) ≈ 0.03 from B0 J/ KS
* no precise measurement of other angles
A. Bay LPHE EPF Lausanne 49
CKM triangle in 2007 (SM)
Picture will be already inconsistent ?
from m
from bc
from bu from B J/ Ks
A. Bay LPHE EPF Lausanne 50
BEYOND 2007 QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
A. Bay LPHE EPF Lausanne 51
Landscapecancelledproposed
under constr.running
2000 2002 2004 2006 2008 2010 2012
BES II BES IIICLEO-ccharm factories
CLEO IIIBABAR
Belle Super-B
B factoriese+e–, √s = m(4S)
ATLASCMSLHCb
LHCpp, √s = 14 TeV We
are here
K experiments BNL E949
KOPIONA48/3CKM
KAMIKEK E391a
CDF IID0
BTeVTevatronpp, √s = 2 TeV
From O.SchneiderInternational WE Heraeus Summer School, Dresden
A. Bay LPHE EPF Lausanne 52
Experiments in hadronic flavour physics
Physics Exp. Machine LaboratoryOperation
dates
B and charm
BABAR PEP-II, ee (4S) SLAC (USA) 1999–2008
Belle KEKB, ee (4S) KEK (Japan) 1999–2009
CDF IITevatron, pp √s = 2 TeV
Fermilab (USA)
2001–2009D0
charm CLEO-c CESR-c, ee (3770), …Cornell (USA)
2003–2008
K E391a 12 GeV PS KEK (Japan) 2004–2006
B
(and high pT)
ATLAS
LHC, pp √s = 14 TeV CERN 2007–CMS
B and charm LHCb
charm BES III BEPC II, ee (3770), … IHEP (China) 2007–B and charm
Super-Belle
Super-KEKB, ee (4S) KEK (Japan) 2011–
K NA48/3 SPS CERN 2009–
K (proposals expected end 2005) JPARC ?
Proposed
Coming soon
Running
A. Bay LPHE EPF Lausanne 53
~Vub
from BXu+l
B0B0
B0
J Ks
W Wt
t
CP Asym ~ sin{ 2 }
t
d
b
tW W
b
d
~
~Vtd
SM view of the unitary triangle from m:
A. Bay LPHE EPF Lausanne 54
~Vub
from BXu+l
new
B0B0
B0
J Ks
W Wt
t
CP Asym ~ sin{2(new)}
t
d
b
tW W
b
d
~
d
b
b
dNEWFCNC
Unchanged
rnew
NEW
Im
Re
~Vtd
SM + New FCNC from m:
A. Bay LPHE EPF Lausanne 55
~Vub
from BXu+l
new
B0B0
B0
J Ks
W Wt
t
CP Asym ~ sin{2(new)}
t
d
b
tW W
b
d
~
d
b
b
dNEWFCNC
Unchanged
rnew
NEW
Im
Re
~Vtd
SM + New FCNC (bis) from m:
A. Bay LPHE EPF Lausanne 56
and new physics from Bd D*n+, D*+n, etc.
Idem with Bs decays:Idem with Bs decays:
snew from CP in Bs J
snew from CP in Bs Ds
K, Ds
K
comparethe two determinations(then combinethem)
Bd D* n vs Bd D* n
Bd D* n vs Bd D* n
From 2( new) +
CP in BJ/ Ks ~ 2( + new)
need to trigger and select hadronic decay channels,
need to study the Bs system, have K/ separation, access to Br < 107….
A. Bay LPHE EPF Lausanne 57
B physics at LHC(b)
• bb ~500 b, 1012 bb / year at L=21032 cm2s
• Bu (40%), Bd (40%), Bs (10%), Bc, and b-baryons (10%)• Many primary particles to determine b production vertex
bb / inelastic ~ 0.6% => triggering problem
Many particles not associated to b hadrons
No B0-B0 entangled states: mixing dilutes tagging
good things:
not so good:
A. Bay LPHE EPF Lausanne 58
LHCb
Forward detector (1.9 4.9)~ 50% acceptance for bb pairs
3 2 1b [rad] 0 1 2 3
b [rad]
B shieldingremoved !
A. Bay LPHE EPF Lausanne 59
LHCb
— RICH detectors for PID—vertex detectors inside beam vacuum
A. Bay LPHE EPF Lausanne 60
VErtex LOcator (VELO)
21 stations, ~200k channels, analogue R/O (Beetle)r- and -measuring stations with Si “striplets”
IP= 14 + 35 /pT
From tracking: p/p = 0.35% – 0.55%
can observe 5 signal if ms < 68 ps1
ms = 25 ps1
BBss oscillation oscillation from Bs Ds
sample
0 1 2 3 4 5 6 [ps]
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
A. Bay LPHE EPF Lausanne 61
LHCbATLAS
0 20 40 60 80 GeV/c
ParticleID
€
B0 → π +π−
RICH1 RICH2
Aerogel& C4F10
CF4
prob ( K)
K efficiency
A. Bay LPHE EPF Lausanne 62
Triggers
1 MHz
40 MHz
Detached vertex
+ IP of pT
candidate
Medium pT hadron,,e,
+ pileup veto
(12.4 MHz of inelastic interactions)
LHCb
40 kHz
L0
L1
B0 J/ KS Bs DsK+ B0
0.88 0.54 0.76 0.90 0.70 0.72
0.79 0.38 0.55
Efficiencies for signal eventsaccepted by offline selection
ln pT ln pT
ln
IP/
IP
ln
IP/
IP
L1L1Signal
Min.Bias
B0 Bs DsK+
Final statereconstruction
~2 kHz
HLT
A. Bay LPHE EPF Lausanne 63
LHCb after 107 seconds
Parameter Channels N untagged
Bd+ 20k @P/T = 30°, |P/T|=0.200.02, =90° 2-5
Bd0 4k @ =50° 5
2+ Bd D* 200k @2+=0 12
BdJ/Ks 200k <0.6
-2 Bs DsK 5400 @ ms=20ps-1 14
Bd D(KK)K* 600 =55°-105° <8
Bs J/ 120k 0.6
Bd + / K+K- 20k/30k @=55°-105° <6 BdKs 0.8k <20 ? ms Bs Ds 80k s/b~3, up to 68 ps-1 (5)
A few penguins : Bs 1.2k Bd K+- 135k Bs K+K- 37k Bd K*0 35k
Bs 9.3k Bd K*0 4.4k(Using PDG branching ratios or SM predictions)
not possibleat B factory
A. Bay LPHE EPF Lausanne 64
CKM triangle in 2007+107 s ?
from B J/ Ks
from md, ms
from bu
from LHCb
Re
Im
A. Bay LPHE EPF Lausanne 65
Key contributions expected from charm factories
• Improve determination of from BDK tree processes:– Measure more precisely D0KS+– Dalitz plot
– Measure D meson strong phase differences appearing in ADS analyses of B+DK+
• Improve extraction of right side of UT from B oscillations measurements:– Measure decay constants fD+ and fDs
from purely leptonic decays:
– Compare with lattice QCD calculations: reduce uncertainty on theory predictions for fB0 and fBs (e.g. rely on LQCD only to predict ratio between B and D constants) reduce theory error in extraction of |Vtd|/|Vts| from md/ms
new,50 evts
new,201±3±17 MeV
€
Γ(D+ → l +ν) =GF
2
8πVcd
2fD+
2 ml2M
D+ 1−ml
2
MD+2
⎛
⎝ ⎜
⎞
⎠ ⎟
2
A. Bay LPHE EPF Lausanne 66
Charm factories
• CLEO-c experiment (Cornell):– Taking data above charm threshold since 2003:
• e+e– (3770) D+D– or D0D0 (281 pb–1 so far)– Plan to go also above Ds threshold (s=4.1 GeV):
• e+e– (…) Ds+Ds
–, …
– May still spend one year on J/ or (2S)– End in 2008
• BES III experiment (Beijing):– BES II stopped in 2004
• 27.7 pb–1 recorded at (3770)– Old BEPC storage ring dismantled this summer to install a new double-
ring machine, BEPCII • design luminosity 1033 cm–2s–1 at (3770) (= 100 times BEPC)
– Major detector upgrade: BESII BESIII – Start of physics commissioning in 2007– Will run on J/, (2S), (3770), etc …