Diapositive 1

1
B physics at ee- Colliders
Achille Stocchi (LAL Orsay/IN2P3-CNRS Université
Paris-Sud)
Alex Bondar (Budker INP,Novosibirsk)
Short introduction. Main motivations
Selection of new measurements
The present situation.
How and why.. to go on
11th INTERNATIONAL MOSCOW SCHOOL OF PHYSICS
(36th ITEP WINTER SCHOOL OF PHYSICS)
Session "Particle Physics" February 8-16, 2008
2
1
Short Introduction. Main Motivations
3
Flavour Physics in the Standard Model (SM) in the
quark sector
10 free parameters
half of the Standard Model
6 quarks masses
4 CKM parameters
Wolfenstein parametrization l ,A, r, h h
responsible of CP violation in SM
In the Standard Model, charged weak interactions
among quarks are codified in a 3 X 3 unitarity
matrix the CKM Matrix.
The existence of this matrix conveys the fact
that the quarks which participate to weak
processes are a linear combination of mass
eigenstates
The fermion sector is poorly constrained by SM
Higgs Mechanism
mass hierarchy and CKM parameters
4
Wolfenstein parametrization 4 parameters l
,A, r, h
The CKM Matrix
d
s
b
u
1-l2/2
l
c
-l
1-l2/2
t
The b-Physics plays a very important
role in the determination of those
parameters
5
Also for angles B physics is crucial
1
a b g p
6
The Unitarity Triangle
radiative decays Xsg,Xdg, Xsll
B? pp, rp, rr...
theo. clean
B? DK
?
other charmonium
Charm Physics (Dalitz)
from Penguins
7
The zoology of the Feynman diagrams (examples..)

• Tree

d
t,sparticules..

• Box

Sensitive to New Physics
FCNC
(Higgs)

• Penguins..

(sparticules..)
8
But finally the diagrams are more..like that
We observe hadrons and not
quarks ! theory gives us the link
from quarks to hadrons OPE /HQET/Lattice QCD
. Need to be tested !
To access the parameters of the Standard
Model we need to control the effects induced by
strong interactions
Many measurements ( with different weights ) are
essential
Decay properties and production characteristics
Lifetimes
Form factors
Branching ratios
Masses (spectroscopy)
Kinematic distributions
beauty and charm physics are equally important
9
Before starting
Exploration of two frontiers
10
2
B factories
11
from O. Schneider
12
Events produced at rest E(B)E(beam)
p350MeV/c? L30?m - Topology isotropical.
-Absence of fragmentation
CLEO/ARGUS
For asymmetric B factories ?? 0.425(0.55)
KEKB(PEP) L200?m (see just later)
e
L1 coherent state
e-
K
The B mesons are produced in pair with no other
accompanying particle. The system B B is in a
coherent L1 state.It means that the two
particles evolve in time in phase, so that at any
time, before the first decay, there are exactly
one B and one B. After the decay of one of the
two mesons the other evolves ( for instance
oscillating between B0 and B0)
?-
?
?????(K ? -) ?
Comments for B0s . The situation is not so
favorable at the U(5S)
13
KEKB asymmetric ee- collider
Two separate rings
e (LER) 3.5 GeV
e- (HER) 8.0 GeV
bg 0.425
ECM 10.58 GeV at ?(4S)
Design
Luminosity1034 cm-2s-1
Current 2.6 / 1.1A
(LER HER)
Beam size sy ?3 mm sx ? 100
mm
11 mrad crossing angle
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At the ?(4S) resonance
ee- ? ?(4S) ? B B
Flavor tag and vertex reconstruction
Boost bg 0.55
?(4S)
m-
B0
m
KS
p
Coherent BB pair, L1
p-
Exclusive B meson and vertex reconstruction
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Reconstruction of B mesons
Initial state kinematic constraint
mbc
energy substituted mass
J/? KS
signal region
DE
sidebands
energy difference
18
3
Introduction to the
Oscillation and CP Violation
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Study of the time dependent behaviour of the B0
-B0 Oscillation
The probability that the meson B0 produced (by
strong interaction) at t 0 transforms (weak
interaction) into B0 (or stays as a B0 ) at time
t is given by
Dmq can be seen as an oscillation frequency 1
ps-1 6.58 10-4 eV
In SM DF2 process
W-
d,s
b
GIM mechanism (Rate m12- m22)
t,c,u
t,c,u
B0d,s
B0d,s
Dominated by t exchange
Rate LARGE
W
d, s
b
Allow to access fundamental parameters
of the Standard Model
Vts
Vtd
23
xgtgt1 rapid oscillation xltlt1 slow oscillation
x is a number the mixing frequency in unit of
lifetime
We also define
Bd
u
W-
d
b
d
t
t
B0d
B0d
W
b
c
d
b
Slow oscillations
24
BB oscillations
25
u
W-
s
Bs
b
d
t
t
B0s
B0s
W
b
c
s
b
Rapid oscillations
u
D0
W-
u
c
d
d,s
d,s
D0
D0
W
c
s
u
c
u
K0
W-
d
s
d
c
c
K0
K0
W
s
u
d
s
26
2
B
f
D
m
B
B
2
2
2
d
h
r
l

-
µ
)
)
1
((
d
d
2
D
m
B
f
s
B
B
s
s
1/x2
Circle around (1,0) in the r-h plane
27
b/b at the production time
B/B at the decay time
Purity of tagging at production time ep
Purity of tagging at decay time ed
Measurement of the decay time
Example at LEP/SLD
All these variables are important and in
particular the time resolution
As soon as Dms becomes larger the precision on
the time measurement becomes crucial
28
LEP
Inclusive Vtx. Dmd 0.5310.0250.007 ps-1
NoMix(t)-Mix(t) NoMix(t)Mix(t)
T2p/Dm
D
Dm (0.516 ? 0.016 ? 0.010) ps-1
29
A Milestone the meaurement of the Bs
oscillations after a long saga..
2
D
B
f
m
B
B
2
2
2
d
h
r
l

-
µ
)
)
1
((
d
d
2
D
m
B
f
s
B
B
s
s
1/x2
CDF only signal at 5s
-0.21
Strong impact on NP on Bs sector. See
later Limiting factor precision on the hadronic
parameter x
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Angles are accessible through CP violating
measurements
B-gtD0K, Kp-
g
a,b,g
B-gtJ/YK, pp-, B-gtDp-
BS-gtDSK-
Analogy Double-Slit Experiments with Matter
and Antimatter
source
In the B experiment, we must choose final states
that both a B0 and a B0 can decay into. We
perform the B experiment twice (starting from B0
and from B0). We then compare the results.
In the double-slit experiment, there are two
paths to the same point on the screen.
34
Direct CP violation occurs because there are
two different ways of reaching the same final
state
In this particular case sensitive to g
D0 and D0 are involved
K-
Color suppressed also possible
s
Vub Vub e-ig
l
W
u
b
b
c
W
Vcb
B-
B-
D0
s
K-
u
u
strong amplitude (the same for Vub and Vcb
mediated transitions
strong phase difference between Vub and Vcb
mediated transitions
Look at D0(CP) states
GLW (Gronau,London,Wyler) Method
ADS (Atwood, Dunietz, Soni) Method
D0 and D0 ? f
D0 and D0 give the same final
35
GLW (Gronau,London,Wyler) Method
ADS (Atwood, Dunietz, Soni) Method
(3.62 0.29)10-3
rB is a crucial parameter. It drives the
sensitivity on g
36
Dalitz method

• Measure B/B- asymmetry across Dalitz plot
• Includes GLW (D0 ? Ks ?0, CP eigenstate) and ADS
  (D0 ? Kp-, DCS 2-body decay)

amplitude
decay
Mirror symmetry between D0 and D0 Dalitz plots
Sensitivity to g in interference term
Determine f in flavor-tagged D?D0p decays
2-fold ambiguity on g (g, dB) ? (gp, dBp)
Model uncertainty
37
Dalitz analysis D0 ? Kspp decay
Statistical sensitivity of the method depends on
the properties of the 3-body decay involved
(For M2Const there is no sensitivity to the
phase ?) Large variations of D0 decay strong
phase are essential
Use the model-dependent fit to experimental data
from flavor-tagged D ?D0p sample ( gt2x105
events) Model is described by the set of
two-body amplitudes flat nonresonant term
As a result, model uncertainty in the ?
measurement
38
Dalitz analysis sensitivity to the phase
39
Belle/Babar results

• HFAG averages for x rB cos( dB g ) , y rB
  sin( dB g )
• Belle/Babar measurements in good agreement
• Note s(f3) depends significantly on the value of
  rB

Contours do not include Dalitz model errors
Contours do not include Dalitz model errors
?82 20 (UTfit)
40
Model-independent analysis
Model-independent way obtain D0 decay strong
phase from ?(3770)?DD data
where
Free parameters
Unknown, can be obtainedfrom charm data
DCP?KSpp
?(3770)?(KSpp)D (KSpp)D
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W-
d
b
t,c,u
t, c, u
B0d
W
d
b
b
c
J/y
c
B0d
s
K0
d
d
B decay
K mixing
Is a general result if the decay is
dominated by a single amplitude Iml is always
given by the sine of twice an angle in the
Unitarity Triangle
45
Direct CP violation
only one amplitude
For J/y K0
46
J/y
b
s
b
c
J/y
t
c
B0d
K0
B0d
s
W
K0
d
d
d
d
Vts Vtb
Vcb Vcs
1) The diagram at tree level is dominant
2) The second diagram (Penguin) has the same
phase at order l2 since Vts is complex and
differs from Vcb at order l4
Extraction of sin2b from J/y K0 theoretically
clean at 1 level
47
Experimental aspects of the sin2b measurement
Acp(Dt)
F(Dt)
F(Dt)
sin2b
Everything perfect ?
D sin2b
Add tag mistakes ? Dilution D1-2w
Add imperfect Dt resolution
?
Dt(ps)
Dt(ps)
Must understand tagging/mistagging and Dt
resolution !!
48
The precision on sin2b is still improving..
direct
indirect
b
c
only one amplitude
J/y
c
B0d
s
K0
d
d
theoretically clean at 0.01 To improved with
data!
Dt(ps)
Dt(ps)
sin2b gives the best constraint on r-h plane
49
Many other modes to measure the angle b. One
example where you can also measure cos2 b
D0gKspp-
50
Many novelties on the measurement of the angle a
Not only Tree diagrams contribute to final
states but also Penguins. Isospin analysis
necessary to extract a
pp modes
rr modes
Important measurement because it gives the
contributions of Penguins diagram
consistent with no CP violation aeff90o (0/180)o
New results also on rp (time dep. Dalitz analysis)
51
4
Determination of the Vub and Vcb
52
n
n
l
l
b
c
b
u
Vcb
Vub
Determined from semileptonic B decays. Decays
at the tree level not affected by New Physics
Circle around (0,0) in the r-h plane
53
Determination of Vcb
Inclusive Method
2
.
exp
theo
.
Br
-

sl
n

G
V

F
cl
b
)
(
cb
sl
t
b
f(m2p , mb , as , rD(or 1/mb3)
Based on OPE
m2p
(l1 Fermi movement)
( also named L)
mb
Essential point is to control /measure the
effects of strong interaction
?Determination of Vcb limited by theoretical
uncertainties ..
54
Issues in Vub measurement

• Experimentally challenging
• Tight selection criteria results in
• Limited phase space
• ? Extra theoretical uncertainties (from
  extrapolation)

55
Main features

• Measure DB(B ? Xu e n, pe gt pcut)
• Kinematic selection
• pe gt pcut
• pcut 1.9, 2.0, 2.1, 2.2, 2.3 and 2.4 GeV/c
• No requirement other than on the
• signal electron
• high statistics
• Large background from B ? Xc e n
• bkg. sys. uncertainty

OPE breaks down ? need shape ftn.!
56
b-quark Shape Function

• What is it?
• b-quark Fermi motion inside the B-meson
• How to get it?
• Universal at leading order for all b ? light
  quark transitions
• Use E(g) in B ? Xs g

57
E(e) spectrum for B ? Xu e n
58
Kinematic selections
(New)
59
Full Reconstruction Method

• Fully reconstruct one of the Bs to tag
• B production
• B flavor/charge
• B momentum

Decays of interests B?Xu l n, p l n ...
B
e- (8GeV)
e(3.5GeV)
?(4S)
p
full (0.10.3) reconstruction B?Dp etc.
B
Single B meson beam in offline !
Powerful tools for B decays study
60
Progress on Vub..
B? Xu l n
Inclusive improving analyses and improving the
control of the theory vs cuts
Br Vub2 in a limited space phase region
Using Babar El, (Xsg)
El
61
B? p l n
B? (exclusive) l n
untagged analysis is the most precise
62
B? p l n
Progress on Vub..
B? Xu l n
Exclusive we start to have quite
precise analysis of Br vs q2
Inclusive improving analyses and improving the
control of the theory vs cuts
Br Vub2 in a limited space phase region
untagged analysis is the most precise
Using Babar El, (Xsg)
Important that we measure at high q2 where
Lattice QCD calculates better.
El
63
5
Extraction
of the
Unitarity triangle parameters
Search for New Physics
64
How measurements constraint UT parameters
g
a
the angles..
sin(2b)
Dms
Dmd
Vub/Vcb
the sides...
CP asymmetries in charmless
B?tn
B?K(r)g

Rare decays... sensitive to NP
65
Crucial Test of the SM in the quarks sector
DONE!!
determination of CP violating parameters
measuring CP-conserving observables
CP-violating observables
was/is the strong motivation of the
B-Factories
B ? J/y K0
sin2b 0.726 0.037
Coherent picture of CP Violation in SM
from sides-only
We are probably beyond the era of  alternatives
to the CKM picture. NP should appear as
corrections to the CKM picture
66
TODAY SITUATION
Total Fit
Dmd,Dms,Vub,Vcb,ek cos2b b a g 2bg
h 0.340 0.017
r 0.164 0.029
67
We want to perform flavour measurements such that
- if NP particles are discovered at LHC we
able study the flavour structure of the NP -
we can explore NP scale beyond the LHC reach
68
(MFV), no new sources of flavour and CP
violation NP contributions governed by SM Yukawa
couplings.
To help with a more specific example
Example for B oscillations (FCNC-DB2)
dbd
pr upper limit of the relative contribution
of NP dbd NP physics coupling Leff NP
scale (masses of new particles)
Minimal Flavour Violation
If couplings 1
all possible intermediate possibilities
dbq 1
Leff 10/?pr TeV
(couplings small as CKM elements)
dbs 1
Leff 2/?pr TeV
dbq 0.1
Leff 1/?pr TeV
Leff 0.08/?pr TeV
Leff 0.2/?pr TeV
dbs 0.1
69
NP physics could be always arround the corner
WHAT IS REALLY STRANGE IS THAT WE DID NOT SEE
ANYTHING.
With masses of New Particles at few hundred
GeV effects on measurable quantities should be
important
Problem known as the FLAVOUR PROBLEM
Leff lt 1TeV flavour-mixing
protected by additional
symmetries (as MFV)
Couplings can be still large if Leff
gt 1..10..TeV
70
Super Flavour Factory
Definition of a Super Flavour Factory (SFF)
gt 1036cm-2 sec-1 ? gt15ab-1 per year (today
1034cm-2 sec-1 Babar400fb-1 Belle700fb-1 )
Background machine to the present one
Possibility of running at lower (t-charm) and
higher energy (Bs)
Simulations are done with 75ab-1
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Super B Factory at KEK
Interaction Region Crab crossing q30mrad. by
3mm New QCS
New Beam pipe
More RF power
Damping ring
Linac upgrade
Lf 8?1035/cm2 /sec
L0 2?1035/cm2 /sec
73
Preliminary schedule for Super Belle Detector
Upgrade
2007
2008
2009
2010
2011
2012
4
7
1
10
4
1
4
7
1
10
4
7
1
10
4
7
1
10
10
Experiment at KEKB
KEKB/Belle upgrade
TDR
Detector Study Report (March 08)
Final detector design (April 09)
2007
2008
2009
4
7
1
1
4
2
10
10
3
5
8
9
11
12
2
3
11
12
6
Detector proposals
Internal review
Pre kick-off meeting (March 08)
BNM (January 08)
Kick-off meeting (July 08)
Meeting plan
One-day general meeting and an IB meeting at
every BGM
We invite new collaborators
74
New site next to Frascati
The Competition based in Italy
Conceptual Design Report has been finished.
Review committee.
Beam size

Question 12 nanometer beam spot in y, 2.7
microns in x. Is this possible in a real 2-3 km
circumference multi-orbit machine ?
(Collaboration on beam dynamics with Ohnishi,
Ohmi)
75
Expected Sensitivities
5ab-1
50ab-1
Super B factory
CPV (b g s)
FCNC
w/ n
CKM
of produced Bs irrelevant to physics reach
comparison
76
Adjusting the central values so that they are
all compatible
Keeping the central values as measured today with
errors at the SuperB
77
At any one time there is a natural tendency among
physicists to believe that we already know the
essential ingredients of a comprehensive theory.
But each time a new frontier of observation is
broached we inevitably discover new phenomena
which force us to modify substantially our
previous conceptions. I believe this process to
be unending, that the delights and challenges of
unexpected discovery will continue always.
Val Fitch, Nobel Prize Speech 1980
78
BACKUP MATERIAL
79
Complementarity LHC/precise measurments
today
r 20 ? Leff 180 GeV
tomorrow
Leff 0.08/?r TeV
r 10 ? Leff 250 GeV
after tomorrow
electroweak scale
r 1 ? Leff 800 GeV
You need to improve 20 times your precision if
you want to span the region from the EW scale to
the TeV scale.
NP scale 200GeV with MFV couplings
NP800 GeV
80
Testing lattice QCD on charm sector form factors

Semileptonic D decays. example D?K l n
fDs, FD from CLEO-C
Precise measurement, test of the QCD calculation
on charm sector ? Could
be used on B sector x, Vub..
81
Variables to suppress b ? c l n
(10 phase sp.)
(80)
(30)
82
Limiting factor F(1) theo. error gt
twice the exp. error
F(1)Vcb 36.2 0.8 ? Vcb 41.4 2.1
inclusive Vcb?Vcb 41.6 0.7 0.6
83
Precision measurements of Vcb
Inclusive Vcb still progress
New technique in b-FACTORIES full
reconstruction of one of the B
BaBar/CLEO/CDF/DELPHI Kinetic scheme
84
Example of single best Inclusive lifetime
measurement
Measurement of Br(sl)
tb 1.570 ? 0.005stat.? 0.008sys. ps
World average
New ideas came few years ago
Which are sensitive to m2p , mb
85
in fact Vcb is the Unitarity triangle
normalization. It enters everywhere !
The precise determination of Vcb is primordial
86
Summary

• Large CP violations seen in B decays
• Excellent agreement with KM ansatz
• sin2f1 ? a new gold standard for New Physics
  searches
• Room for New Physics is pretty small
• either the NP mass scale is very high
• or NP is somehow hidden from the flavor sector
• NP searches with Bs have another
  order-of-magnitude of reach
• A phased approach to Super-KEKB/Belle seems
  likely

87
Time Dependent CPV in B0 decays
e.g. for B?J/? Ks S -?CPsin2f1 sin2f1 A
0 (?CP CP eigenvalue ?1)
Mixing-induced CPV
Direct CPV
N.B. Time integrated mixing-induced asymmetries
vanish
88
leptonic decay B?ln
SM expectation
Milestone First leptonic decay seen on B meson
First test can be done, not yet precise
BR(B ? t ?) (0.85 0.13)10-4
SuperB
Exp. likelihood BABARBELLE BR(B ? t ?) (1.31
0.48)10-4
() systematically limited (to be studied with
the improved detector)
Br(B?tn) up to 3-4 (below limited by
systematics) ..probably not
with improved detector. Br(B?mn) can be measured
with the same precision not
limited by syst.
89
sin2b from s Penguins
Many channels can be measured with DS(0.01-0.04)
W-
s
b
SuperB
f
t
s
B0d
s
K0
d
d

g


s
b
b
s
() theoretical limited
90
The angle a
rr modes
Isospin analyses performed at the
B-factories s(a) _at_ 100
Important measurement because it gives the
contributions of Penguins diagram
Some very important measurements start to be
possible only now with about 0.5ab-1
consistent with no CP violation aeff90o (0/180)o
Each of pp,rp,rr analysis will be allow to get
s(a)2 degrees
It allow consistency checks and to control
theoretical uncertainties on data
SuperB
s(a)1o possible
() theoretical limited
91
Best measurements from Dalitz analysis with
D0?Kspp
The angle g
The model error can be reduced by running at
threshold
New D0 decays starting to be explored
Error vs DCP statistics
BaBar
Bondar Poluektov hep-ph/0510246
Many independent methods GLW, ADS, Dalitz, with
many different decay channels
SuperB
s(g)1o possible
92
Radiative B decays
SuperB

• - many measurements on B?sg
• - measurements of Br on B?rg
• measurement of ACP on
• exclusive and inclusive modes

() systematically limited
() theoretically limited
Significant improvement on b?dg ACP in inclusive
decay at 0.5 ! (SM0.5)

• Measurements of Br done
• We start to perform AFB measur.

SuperB
CP and FB asymetries in sll exclusive and
inclusive decays at few per cent
93
B?tn at 4
B?mn at 5
CP asymetries in radiative exclusive and
inclusive decays at a fraction of 1
CP and FB asymetries in sll exclusive and
inclusive decays at few per cent
94
Example other modes B0 ? D0 h0
SuperB will be able to make complementary
measurements (beyond J/y K0) that help to
ensure that the theoretical uncertainties are
under control and to control them on data
Babar
SuperB
Important points - We know how to perform
these analyses - Very significant improvement
from now?2ab-1? Superb luminosity
95
angle g
Dalitz Method -
new technique which make use of the D0 three-body
decays
Plot of the weights (second derivative wrt g)
Ks r(pp-) CP-GLW method
D0 ? KS p p-
BaBar
Interference due to the overlap of large
resonances from Cabibbo allowed Vcb and Vub
transitions
K (1430)
K (892)(Ks p) p-) ADS method
96
The way out is to use neutral and charged B and
to measured all the possible branching fractions
and CP asymmetries in the given system and rely
on SU(2)
Starting from SU(2) amplitudes
pp-
pp0
p0p0
Uknowns 6 T, P, TC ,,dP, dTC, a
Observable 8 3Br-fractions,
C-,S-,ACP(0),C00,S00
The angle a is measured using pp,rr and rp
97
Angles are accessible through CP violating
measurements
g
a,b
Analogy Double-Slit Experiments with Matter
and Antimatter
source
In the B experiment, we must choose final states
that both a B0 and a B0 can decay into. We
perform the B experiment twice (starting from B0
and from B0). We then compare the results.
In the double-slit experiment, there are two
paths to the same point on the screen.
98
We want now to have the evolution of a meson B0
(flavour eigenstate) after the time t0 of its
creation (consider
)
It follows
MASTER FORMULA
99
Violation in the interference between decay and
mixing in case B decays in CP state
decay
B0
f ( f )
decay
mixing
B0
100
Back to B0
Introducing
Similar equations for
Here t should be changed in Dt(t(CP-decay)
- ttag)
101
Observation of direct CP violation in B0?Kp-
232x106 BBs
New Belle Result -0.113/- 0.022/- 0.008
But angle g cannot extracted from it, since it
depends upon weak phase and strong amplitude and
phase
102
Large ACP
requires amplitudes of similar order Example
b?u suppressed tree charmless decays
(competitive channels , as Penguins)
Acp(B0?Kp-) -0.095/- 0.013
So far the only confirmed case for direct CP
violation in B decays
103
K-
Direct CP Violation - Generalia
s
W
W
s
b
u
b
K-
Vub
t
B-
B-
p0
u
p0
u
u
In this case
104
Considering only the mixing
If you add DG (useful for the discussion on
charm) the previous formula become
105
In a general way we can write
If CPT
Solving the eigenvalues equation it follows
For B system
useful def.
B0 bd B0 bd
Eigenstates of flavours
def hh1
CP Eigenstates
106
Dms
Combine many different analyses which give limits
Combination using the amplitude method
Measurement of A at each Dms
107
Flavour is treated in great details at this school
108
Some discrepencies observed between Vub and sin2b
sin2b0.6750.026 From direct measurement
We should keep an eyes on these kinds of
disagreements. Could be NP
sin2b 0.764 0.039 from indirect
determination (all included by sin2b)
109
SM Fit
No disagreement for g et Dms
110
Comparison measurements with angles wrt with
sides
111
From Childhood
In 2000 the first fundamental test of agreement
between direct and indirect sin2b
To precision era
WE HAVE TO GO ON
112
An example on how to fit the UT parameters and
fit new physics
113
Higgs-mediated NP in MFV at large tanb
Similar formula in MSSM.
Excl. 2s
B?ln
MH (TeV)
tanb
2ab-1 MH0.4-0.8 TeV for tanb30-60
SuperB MH1.2-2.5 TeV for tanb30-60
114
Constraints on b -gt s transitions

g
CFMS


s
b
s
b
New Physics contribution (2-3 families)
115
Example on how precise measurements could allow o
explore NP scale beyond the TeV scale

g
MSSM


New Physics contribution (2-3 families)
s
b
s
b
1 10-1 10-2
In the red regions the d are measured with a
significance gt3s away from zero
1 10
ACP(b?sg)
With the today precision we do not have 3s
exclusion for any set of parameters
116
A milestone in B physics the measurement of the
leptonic decay B?tn First leptonic decay seen on
B meson
SM expectation
BR(B ? t ?) (0.85 0.13)10-4
Exp. likelkihood BABARBELLE BR(B ? t ?) (1.31
0.48)10-4
fB 237 37 MeV from expUTfitfB 189 27
MeV Lattice QCD
117
Leptonic B rare decays B?Xs l l -
Sensitive to new physics
l
l
l
g
l
All perfectly agree with theory predictions.

• Measurements of Br done
• We start to perform AFB measur.

118
Observation of the b?dg decays B?r (w) g
119
b?s,d penguins radiative decays (dominated by a
single amplitude in SM)
? small predicted ACP
Fantastic probe of NP
120
Radiative penguin decays of B mesons
Now its a physics program!
Observation of B?K g CLEO II (1993) Loops in B
decays
121
B oscillations allow to address Vtd and Vts CKM
elements
also radiative and leptonic rare B decays
K
g
W -
Radiative B decays
u,c,t
b
p-
s,d
g
Vtd , Vts
q
q
b? s (d) g
B ? K(K p -) g
Inclusive decays are cleaner
(excl. depends upon not very well known form
factors)
Loops sensitive to New Physics (heavy objects
in the loop). ACP one of the best probe of NP in
the b?s sector
Photon energy spectrum depends on the quark mass
and Fermi movement ? important for
addressing theoretical error for Vcb (see later)
if b? dg is also measured Br(b? dg )/
Br(b? sg )? Vtd/Vts 2
same constraint as Dmd/ Dms
122
fBd (-3.0 2.0)o
CBd 1.24 0.43
ANP/ASM vs fNP
With present data ANP/ASM0 _at_ 2s
ANP/ASM 1 only if fNP0 ANP/ASM 0-40 _at_95
prob.
123
Fit in a NP model independent approach
DF2
Parametrizing NP physics in DF2 processes
Tree processes
5 new free parameters Cs,js Bs mixing
Cd,jd Bd mixing CeK K mixing
1?3 family
Constraints
2?3 family
Today fit possible with 10
contraints and 7 free parameters (r, h,
Cd,jd ,Cs,js, CeK)
1?2 familiy
124
sin2b from s Penguinsa lot of progress..

g


s
b
b
s
New Physics contribution (2-3 families)
Disagreement between sin2b from b?ccs and
b?qqs still there and intriguing..
125
Life is not always so simple.
Phase of Vub
Tree diagrams(T)
p
p-
b
b
u
u
B0d
B0d
p-
p
d
d
d
d
Order Vub l3
BUT

• Two kind of diagrams are of the same order

W
2) and different phases Vub and Vtd
t
b
d
u
the amplitudes of different contributions have
to be taken into account to know the total weak
phase
B0d
u
d
d
Penguin diagrams (P)
In fact also Color suppressed diagrams contribute
Order Vtd l3
So in this case we measure both C and S
126
RESULTS ON g
r comes out to be small. more difficult to get a
precise measurement of g
? (83 19)o (up to p ambiguity)
rDK 0.071 0.024
127
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128
Impressive experimental activity in the last 12
year
LEP/SLD/CDF 1993-2002
B-factories 2000?
129
Today
Bit of history
130
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131
An example on how to fit the UT parameters and
fit new physics
132
B0 ? D0 h0
Together with J/y Kp , DDK
Help in distinguishing between the two b solution
from sin2b measurement
133
The angle g still quite a lot of work to do
Most precise measurement come from Dalitz
analysis with D0?Kspp
critical the value of rb
Babar more precise than Belle on x,y but found a
smaller rB larger error on g
New D0 decay explored
BaBar
134
Precision measurements of Vcb
Essential point is to control /measure the
effects of strong interaction
Inclusive Vcb still progress
Same for exclusive..
B?Dln
(Babar)
Events/0.5
here we extract
limiting factor F(1)
BaBar/CLEO/CDF/DELPHI Kinetic scheme
Study on charm sector help in the understanding
of strong dynamics
135
Radiative B decays moving beyond B?Kg
- many measurement on B?sg - measurements of Br
on B?dg - measurement of ACP on exclusive and
inclusive modes
136
SM Fit
No disagreement for g et Dms
137
Violation in the interference between decay and
mixing
mixing
decay
In general you should study
And fit
decay
B0
f ( f )
decay
mixing
Special case the final state f is a CP
eigenstate
B0
Only one quantity
138
t o d a y L H C b
139
NP scale at 350 GeV
Due to the actual disagreement betweenVub and
sin2b we see a slight hint of new physics
Re (dd13)LL vs Im (dd13)LL superB if disagreement
disapper.
SM
Re (dd13)LL vs Im (dd13)LL with
present disagreement
NP at high significance !
Constraint from Dmd Constraint
from sin2b cos2b Constraint from sin2b
All constraints
140
MSSM

g
With the today precision we do not have 3s
exclusion
New Physics contribution (2-3 families)


s
b
b
s
1 10-1 10-2
1 10-1
In the red regions the d are measured with a
significance gt3s away from zero
1 10
1 10
In this case the main constraints are b?sg
ACP(b?sg)
Today we would have magenta contour
covering all the space