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B physics at Belle (and beyond)
Aurelio BayLPHE/IPEP
CP violation and B physics, introduction KEK-B and the BELLE detector Results from Belle: constraining the UTBeyond 2007 (LHCb)
Summary:
v2
Colloquium, PSI January 2004
A. Bay 30 I 2004 2
CP violation
K0L
e
e CPMIRROR {
CP symmetry implies identical rates. Instead...
K0L is its own antiparticle
K0L
S. Bennet, D. Nygren, H. Saal, J. Steinberg, J. Sunderland (1967):
July 1964: J. H. Christenson, J. W. Cronin, V. L. Fitch et R. Turlay
small CP violation with K0 mesons
e Ne N e Ne N + %
providesan absolutedefinition
of + charge
Asymmetry =
A. Bay 30 I 2004 3
K0
K0
€
K0 → π +π−
CP b
K 0 → π +π−
Processes should beidentical but CPLearfinds that
neutral kaondecay time distribution
anti-neutral kaon
decay time distribution
Other experiments: NA48, KTeV, KLOE factory in Frascati, ...
CPLear
A. Bay 30 I 2004 4
Baryogenesis
1) processes which violate baryonic number conservation:
B violation is unavoidable in GUT.
2) Interactions must violate C and CP.
C violated in Weak Interactions.CP violation observed in K and B decays
.
3) System must be out of thermal equilibrium
OK : Universe expands.
Starting from a perfectly symmetric Universe: 3 rules to induce matter-antimatter asymmetry during evolution
Andrej Sakarov 1967
B(t=0) = 0 B(today)>0
e+e annihilation fromthe center of the Galaxy
rate compatible with secondary production !
A. Bay 30 I 2004 5
How to generate CPVHamiltonian H = H0 + HCPV with HCPV responsible for CP violation.Let's take HCPV = gH + g*H† where g is some coefficient.The second term is required by hermiticity.
CP HCPV CP† = CP (gH + g*H†) CP† = gH† + g*H
CP is violated, HCPV CP HCPV CP† if gH + g*H† gH† + g*H
The conclusion is that CP is violated if g g*
CP violation is associated to the existence of a complex component in thehamiltonian.
A. Bay 30 I 2004 6
CPV and the Standard Model .2
L = L W,Z + L H + L Fermions + L interaction
L Fermions contains the (Yukawa) mass terms:
€
H
vevu L c L t L( )MU
uR
cR
tR
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
+ d L s L b L( )MD
dR
sR
bR
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
⎡
⎣
⎢ ⎢ ⎢
⎤
⎦
⎥ ⎥ ⎥
MU and MD complex matrices, diagonalized by a couple ofnon-singular matrices, to get the physical mass values:
€
ALMUAR−1 =
mu
mc
mt
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
€
BLMDBR−1 =
md
ms
mb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
A. Bay 30 I 2004 7
CPV and the Standard Model .3
€
uR
cR
tR
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟→ AR
−1
uR
cR
tR
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
uL
cL
tL
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟→ AL
−1
uL
cL
tL
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
After the transformation
(idem for D quarks)
e.m. and neutral currents unaffected. The charged currents are modified:
€
Jμch arg ed ∝ d L s L b L( )γμBLA R
−1
uL
cL
tL
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟= d L s L b L( )γμ V
uL
cL
tL
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
"mixing matrix" V unitary
s
uW
Vus
A. Bay 30 I 2004 8
CPV and the SM .4Parameters Vij are used to calculate the
transitions quark(i) quark(j)first introduced by N. Cabibbo for i,j=u, d, s
In 1972 Kobayashi & Maskawa show that, in order to generateCP violation (i.e. to get a complex phase), V must be (at least) 3x3 prediction of the three quark families of the SM: (u, d), (c, s), (t, b)
VCabibbo is real. CPV implies that some of the Vij are complex !
s
uW
Vus
€
Vud Vus
Vcd Vcs
⎛
⎝ ⎜
⎞
⎠ ⎟=
cosθ sinθ
−sinθ cosθ
⎛
⎝ ⎜
⎞
⎠ ⎟≈
0.97 0.22
0.22 0.97
⎛
⎝ ⎜
⎞
⎠ ⎟VCabibbo=
The c introduced in 1970 (GIM), discovered in 1974.
Cabibbo~ 12°
A. Bay 30 I 2004 9
down strange beauty up 0.97 0.22 0.002charm 0.22 0.97 0.03 top 0.004 0.03 1
CKM matrix
€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟≈
1− λ2 /2 λ Aλ3 ρ − iη( )
−λ 1− λ2 /2 Aλ2
Aλ3 1− ρ − iη( ) −Aλ2 1
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟+ O(4)
= sin(Cabibbo) ~ 0.22 phase: changesign under CP
parametrized by 4 real numbers (not predicted by the SM).Need to measure them.
Magnitude ~
Wolfestein (1983)
A. Bay 30 I 2004 10
down strange beauty up 0.1% 1% 17%charm 7% 15% 5% top 20% ?% 29%
CKM matrix
€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
Vij)/Vij ~
From direct measurements, no unitarity imposed:
A. Bay 30 I 2004 11
CKM matrix .2
€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟≈
1− λ2 /2 λ Aλ3 ρ − iη( )
−λ 1− λ2 /2 Aλ2
Aλ3 1− ρ − iη( ) −Aλ2 1
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟+ O(4)
down strange beauty up 0 0 115°charm 0 0 0 top 25° 0 0
Phase ~ down strange beauty up 0 0 115°charm 0 0 0 top 25° 0 0
Wolfestein (1983)
A. Bay 30 I 2004 12
CKM Matrix and the Unitary Triangle(s)
€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟≈
1− λ2 /2 λ Aλ3 ρ − iη( )
−λ 1− λ2 /2 Aλ2
Aλ3 1− ρ − iη( ) −Aλ2 1
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟+ O(4)
SM Unitarity Vji*Vjk=ik VudVub + VcdVcb
+ VtdVtb = 0
V udV ub
VcdVcb
Vtd V
tb *
*
*
Re
Im
The UnitaryThe Unitary TriangleTriangle
A. Bay 30 I 2004 13
CKM Matrix and the Unitary Triangle(s)
+ O(4)
€
Vud Vus Vub
Vcd Vcs Vcb
Vtd Vts Vtb
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟≈
1− λ2 /2 λ Aλ3 ρ − iη( )
−λ 1− λ2 /2 Aλ2
Aλ3 1− ρ − iη( ) −Aλ2 1
⎛
⎝
⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟
SM Unitarity Vji*Vjk=ik VudVub + VcdVcb
+ VtdVtb = 0
Area CPV !
The UnitaryThe Unitary TriangleTriangle
afternormalization byVcdVcb*=A3
Re
Im
1€
−iη
€
1− ρ − iη
A. Bay 30 I 2004 14
Experimental program: measure sides and angles
* 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 30 I 2004 15
QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
The B mesons family
€
B 0 = bd B− = bu
B s0 = bs Bc
− = bc + antiparticles
M (B) ≈ M (B0) ≈ ≈ 5279 MeV/c2
lifetime ≈ 1.5 1012 s
mixing/oscillation
b s,d
u,c,t
WQuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
B0 B0
d
b
u,c,t
W W
b
d
QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
€
l
W
b u,c
direct decay
loop decay
B factories
u,c,t
A. Bay 30 I 2004 16
New Physics...may modify rates and inject new phases in the processes. For instance:
d
b
W W
b
d
d
b
b
d
NewFCNC
VtsV
tb*
B0b
d
s
s
d K0
s
W
t
??????
b
d
s
s
d K0
s
squark+?
+?
( MSSM has 43 additional CP violating phases ! )
A. Bay 30 I 2004 17
(Open a parenthesis: masses & mixingsIn the SM, CPV is related to the mass generation mechanismfor the fermions. The fermionic system is far to be understood.
Is there any "periodicity" in the mass spectrum?
Similar question for the mixing matrices.
A. Bay 30 I 2004 18
Any horizontal symmetry ?
CPV, mix., baryogenesis: hep-ph/0108216v2 *Neutrino mix and CPV in B: hep-ph/0205111v2Bs-Bs mixing in SO(10) SUSY GUT linked to mix. hep-ph/0312145
A. Buras, J. Ellis, M.K. Gaillard and D.V. Nanopoulos, Nucl. Phys. B135 (1978) 66
Lepton-quark mass relations first (?) discussed by
...close the parenthesis)€
u c t
d s b
⎛
⎝ ⎜
⎞
⎠ ⎟e μ τ
ν ν ν
⎛
⎝ ⎜
⎞
⎠ ⎟
€
SU(3)C ⊗ SU(2)L ⊗U(1)Y ⊗ SU(x)H
V
H
(CKM)(NMS)
?
A. Bay 30 I 2004 19
KEK-B
8 GeVelectrons
3.5GeV positron
IP: IP: xx7777 µm µm y y 2 2 µm µm z z 4 4 mmmm
E*E*beambeam) = 2.6 MeV) = 2.6 MeV
LLdt ~ 180 fbdt ~ 180 fb–1–1
at at (4S)+off res(~10%)(4S)+off res(~10%)
production of(4s) (10.58GeV/c2) = 0.425(4s) B0 B0
B+ B
24% Y(4s)76% continuum
A. Bay 30 I 2004 20
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
KEK-B year 2003: crossing the(psychological) barrier of 1034 cm-2s-
1 Luminosity trend in the last 30 years
Pea
k lu
min
osit
y cm
s
24 I 20004: 24h integrated lumi record: 730.3 pb
A. Bay 30 I 2004 21
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.Has collected ~150 million BB pairs
Particle ID : dE/dx in CDC dE/dx =6.9% TOF TOF = 95ps Aerogel Cerenkov ACC Efficiency = ~90%, Fake rate = ~6% 3.5GeV/c
/ KL detection 14/15 layers of RPC+Fe : efficiency > 90%<2% fake at p > 1GeV/c
A. Bay 30 I 2004 22
Micro-vertex detector
A. Bay 30 I 2004 23
event Belle
x
z1 mm
A. Bay 30 I 2004 24
Particle ID in BelleParticle ID uses information from
ACC, TOF, dE/dx( CDC)
€
Prob to be a K{ } =L(K)
L(π) + L(K)
Barrel ACC
Endcap ACC
dE/dxTOF
p (GeV/c)
cut
A. Bay 30 I 2004 25
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
A. Bay 30 I 2004 26
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 30 I 2004 27
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 B daughtersand calculate its (pB,EB)Boost to c.m.
"beam constrained mass"
€
Ebeam* ≡
s
2
Example:B D0
A. Bay 30 I 2004 28
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 30 I 2004 29
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 neutrino 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 30 I 2004 30
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 30 I 2004 31
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 30 I 2004 32
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 30 I 2004 33
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 30 I 2004 34
F. Ronga
average
md and Vtd HEP-PH/0206171
From: F. Ronga, PhD Thesis, Lausanne XII 2003
€
Vtd ∝ Δmd fB BB
Bagparameter
B decayconstant
|Vtd | ~ (8±2)10-3
~20% error !
{
A. Bay 30 I 2004 35
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 30 I 2004 36
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 30 I 2004 37
Any "direct" CP violation ?
b
dB0
Vcb
cc
sKs
J/
dB0
Vtb c
Ks
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 30 I 2004 38
ime 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 30 I 2004 39
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 30 I 2004 40
A large CP asymmetry has been observed!
Belle: SCP = 0.733 ± 0.057 ± 0.028
BABAR: SCP = 0.741 ± 0.067 ± 0.033
World average: SCP = 0.736 ± 0.049
J/KL
ACP~ 0, compatible with no direct CPV
SM: SCP = sin(2) => or 66.3°)
mainly tag and vtx reconstruction
J/KLv is OK
A. Bay 30 I 2004 41
SM & KM model is verified ! sin2 (Belle, 140 fb-1) =
0.733±0.057±0.028
sin2 (BaBar, 81 fb-1) =
0.741±0.067±0.033
sin2 (World Av.)
=0.736±0.049
= 23.7°± 2.1° = 66.3°± 2.1°
A. Bay 30 I 2004 42
UT with sin2
The UnitaryTriangle
fit including sides,
K0 data,and
sin2
A. Bay 30 I 2004 43
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 30 I 2004 44
B0 Ks .26811 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 30 I 2004 45
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 30 I 2004 46
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° very preliminary
A. Bay 30 I 2004 47
Belle:very, verypreliminary
A. Bay 30 I 2004 48
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 alsoB0B+
d
b
W
tg
d
uu
d
0B
+
-
This is not the case: large"penguin pollution" expected(but intrinsically interesting..!)
Consider B0first:
A. Bay 30 I 2004 49
B0
Submitted to 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 30 I 2004 50
B0
Belle
BaBardirectCVP
A. Bay 30 I 2004 51
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 30 I 2004 52
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 30 I 2004 53
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: 500–1000 fb-1
CLEO-C
(sin(2)) ≈ 0.03 from B0 J/ KS
* no precise measurement of other angles
A. Bay 30 I 2004 54
CKM triangle in 2007 (SM)
Picture will be already inconsistent ?
from m
from bc
from bu from B J/Ks
A. Bay 30 I 2004 55
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 30 I 2004 56
~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 30 I 2004 57
~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:
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~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 30 I 2004 59
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
compare the two determinations(then combine them)
Bd D*nvs 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….
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B physics at LHC(b)
• bb ~500b, 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:
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LHCb
Forward detector (1.9 4.9)~ 50% acceptance for bb pairs
3 2 1b [rad] 0 1 2 3
b [rad]
B shieldingremoved !
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LHCb
— RICH detectors for PID—vertex detectors inside beam vacuum
Magentic momentumanalysis in the vtx detector
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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.
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LHCbATLAS
0 20 40 60 80 GeV/c
ParticleID
€
B0 → π +π−
RICH1 RICH2
Aerogel& C4F10
CF4
prob ( K)
K efficiency
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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
200 Hz
HLT
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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
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CKM triangle in 2007+107 s ?
from B J/Ks
from md, ms
from bu
from LHCb
Re
Im
A. Bay 30 I 2004 68
Summary
Measurements of B0 hh, ... Observation of X(3872), narrow D2state or a DD* molecule ?
Tests of QM, EPR&Bell.
Many other results
The main goal of Belle experiment is CPV study in B decays:
sin2 = 0.733±0.057±0.028 Large CPV in B0 (direct CPV ?)S : sin2 = –0.96 ±0.50 ±0.11: hint of New Physics or statistical fluctuation?
B physics at LHC will get a big boost from 1012 bb / year at 21032 cm2s1 including Bs mesons
LHCb is an experiment dedicated to B physicshadronic trigger and topological trigger, optimized particle ID and proper time resolution
Precise determination of the Unitary Triangles angles, in particular, with different methods.If new physics shows up, measure the relevant parameters.
