Transcript Diapositive 1

B
→
K
*
γ
)
Introduction to
Heavy Flavour Physics
(..more on CKM and CP violation)
Achille Stocchi
(LAL Orsay/IN2P3-CNRS
Université Paris-Sud)
in 25 minutes
Short introduction. Main motivations
Selection of new measurements
The present situation.
How and why.. to go on…
Moriond QCD
17 -24 March 2007
La Thuile, Italy
Short Introduction.
Main Motivations
~ half of the
Standard Model
Flavour Physics in the Standard Model (SM) in the quark sector:
10 free parameters
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
The Unitarity Triangle:
radiative decays Xsg,Xdg, Xsll
B pp, rp, rr...
theo. clean
?
B DK
Charm Physics
(Dalitz)
+other charmonium
+from Penguins
How measurements constraint UT parameters
a
g
sin(b+g)
the angles..
sin(2b)
Dms
Dmd
Vub/Vcb
the sides...
BK*(r)g
Btn
CP asymmetries in charmless
…
Rare decays...
sensitive to NP
From Childhood
In ~2000 the first fundamental
test of agreement between
direct and indirect sin2b
To precision
era
WE HAVE TO GO ON…
Before starting…
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
Branching ratios
beauty and charm physics
are equally important
Form factors
Masses (spectroscopy)
Kinematic distributions
Selection of
new measurements(*)
(*) some (partial) selection of important measurements which will be
discussed at this conference. Touch and go. A sort of “fil rouge”
There are many others, apologies for not treating them.
I put some results on the backup material
Angles are accessible through CP violating measurements
A1
B0
g
Direct also with B+
fCP
direct
A2
a,b
A1
M12
G12
A2
B0
Analogy: “Double-Slit” Experiments with Matter and Antimatter
source
A1
A2
A1
A2
In the B experiment, we must choose final
states that both a B0 and a B0 can decay into.
In the double-slit experiment, there are
We perform the B experiment twice (starting
two paths to the same point on the screen.
from B0 and from B0). We then compare the
results.
The precision on sin2b is still improving..
b
B
c
c
s
d
0
d
d
J/y
K0
~only one amplitude
a fCP (t )  C f cos Dmdt + S f sin Dmdt
direct
indirect
Cf  0
S f  hCP sin2b
theoretically clean
at ~0.01
To improved with data!
Dt(ps)
0.678  0.026
Dt(ps)
0.002  0.021
sin2b gives the best
constraint on rh plane
sin(2b)
sin2b from “s Penguins”…a lot of progress..

W
b
B
t
0
d
d
s
s
f
s
d
K0
~
g
b
~
b
( )
d
~
s
s
23 LR
New Physics contribution (2-3 families)
Disagreement between
sin2b from bccs and bqqs
still there and intriguing..
“CP violation observed
in h’Ks”
Some discrepencies observed between Vub and sin2b
sin2b=0.675±0.026
From direct measurement
sin2b =0.764± 0.039
from indirect determination
(all included by sin2b)
We should keep an eyes on these kinds
of disagreements. Could be NP
B Xu l n
Progress on Vub..
Inclusive : improving analyses and
improving the control of the theory vs cuts
Br ~ |Vub|2 in a limited
space phase region…
B p l n
Exclusive :
we start to have quite precise
analysis of Br vs q2
untagged analysis
is the most precise
Using Babar El, (Xsg)
Important that we measure
at high q2 where Lattice
QCD calculates better.
El
Confirming
disagreement…
2
f
B Bd
m
D
B
d 
d
A Milestone :
f B2s B B s
the meaurement of the Dm s
Bs oscillations
after a long saga..
1/x2
l 2 ((1  r ) 2 + h 2 )
Dms
Dmd
LEP/SLD 1999
CDF 2006
LEP/SLD
2002
SM predictions
of Dms
-0.21
CDF only : signal at 5s
-1
Dms  17.33+0.42

0.07
ps
0.21
Dmd  0.507  0.004 ps-1
Strong impact on NP on Bs sector. See later
Limiting factor : precision on the hadronic parameter x
A second milestone :
the measurement of the leptonic decay Btn
First leptonic decay seen on B meson
SM expectation
BR(B → τ ν) = (0.85 ± 0.13)10-4
Exp. likelkihood BABAR+BELLE
BR(B → τ ν) = (1.31 ± 0.48)10-4
fB = 237 ± 37 GeV from exp+UTfit
fB = 189 ± 27 GeV Lattice QCD
Use D0 from D* to tag
the flavour of D0
D*+ D0 +

p
x 
Dm
,
G
0
RWS (t )

 K p + / D (t ) 
Mixing in D0 -D0 system Observed !!
BaBar
y 
x'
y'
DG
2G
2

 K p + / D 0 (t ) 
 RDCS
D0
Submitted to PRL (hep-ex/0703020)
RDCS
DCS
decays
RWS
Wrong sign : WS
+
+
RDCS
 x cos + y sin
  x sin + y cos
'



y
0 
t
(
D
)


t
Interference
RDCS y
'
+
x '2 + y '2
2
 t 


 t (D0 ) 


D0
2
Oscillations
(1 ± cosDm t) ~ x2/2
idem for DG ~ y2/2
K p+
 strong phase CF/DCS ampl.
rotation (x,y)(x’,y’)
3.9s evidence
no mixing
mixing
no mixing
y '  (9.7  4.4  3.1) 103
x'2  (0.22  0.30  0.20) 103
Belle :
Method using Dalitz ex : D0 K0S p  p +
RS and WS occupy the same Dalitz plot
Measurement of strong phase 
Constraint on x,y2
( also sensitive to sign of x)
CP eingenstate lifetimes
DG
t ( K p + )

2G
t ( K  K + )ort (p +p  )
 1
KK+ (or p p +) pure CP D10
Kp+
50% D10 + D20
Constraint on y
Compare assuming =0:
(x'=x, y'=y)
2.4s
Best fit
Belle life. (1s)
Belle Dalitz
ALL is very exciting. D mixing is
Now observed, we need more
Measurements with different techniques
to get x and y parameters.
Within 2s,
less if 0
Two talks tomorrow
+theory talk….
Testing lattice QCD on charm sector : form factors
fDs, FD from
CLEO-C
Semileptonic D decays.
example DK l n
D
Precise measurement, test of the QCD calculation on charm sector
 Could be used on B sector : x, Vub..
The present situation
How and Why.. to go on…
I’ll discuss the present knowledge of the CKM matrix and CP violation in
the SM and beyond and at the same time try to see what do we need ( theory
and next facilities) to effectively look for NP
I’ll use some simulation done for a possible SuperB facility with 75ab-1
Global Fit
Dmd,Dms,Vub,Vcb,ek + cos2b + b + a + g + 2b+g
r = 0.163 ± 0.028
h = 0.344 ± 0.016
We are beyond the era of « alternatives» to the CKM picture.
NP should appear as «corrections» to the CKM picture
SM Fit
The problem of particle physics today is :
where is the NP scale L ~ 0.5, 1…1016 TeV
The quantum stabilization of the Electroweak Scale
suggest that
L ~ 1 TeV
LHC will search on this range
What happens if the NP scale is at 2-3..10 TeV
…naturalness is not at loss yet…
Flavour Physics explore also this range
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
 bq
L ef f
Fit in a NP model independent approach Dm EXP  C Dm SM
d
q
d
ACP ( J / K 0 )  sin(2b + 2fd )
Parametrizing NP
physics in DF=2 processes
Cq e
2ijd
a EXP  a SM  fd
SM
QDNP
+
Q
 B 2 SM DB 2
QDB 2
| e K |EXP  Ce | e K |SM
r,h
Constraints
Tree
processes
13
family
g (DK)
X
Vub/Vcb
X
Dmd
X
ACP (J/ K)
X
ASL
a (rr,rp,pp)
Cd
jd
Cs
js
5 new free parameters
Cs,js Bs mixing
Cd,jd Bd mixing
CeK
K mixing
X
X
X
X
X
X
X
X
X
23
family
DGs/Gs
X
Dms
X
12
familiy
eK
X
g (DsK)
~X
X
X
X
Today :
X
In future :
ASL(Bs)
No new physics
C=1 j=0
CeK
X
X
ACH
ACP (J/ f)
DF=2
X
fit possible with 10 contraints
and 7 free parameters
(r, h, Cd,jd ,Cs,js, CeK)
if SuperB
Model Indep. Analysis in DB=2
C = ± 0.031
f = (± 0.5)o
C = 1.24 ± 0.43
f = (-3.0 ± 2.0)o
Cq e
2ijd
SM
QDNP
+
Q
 B 2 SM DB 2
QDB 2
Factor 3-4 gain
on NP scale
NP~700 GeV
NP scale ~200GeV
with MFV couplings
In some more favourable case
MH (TeV)
Precision will be enough to
have 5s discrepancy with today
central values
Similar plots in Bs sector
where the impact of LHCb is crucial
tanb
Example on how precise measurements
could allow to explore NP scale
beyond the TeV scale
~
g
~
b
b
( )
d
|  23 |LR
MSSM
~
s
s
23 LR
New Physics contribution
(2-3 families)
1
In the red regions the 
are measured with a
significance >3s away
from zero
10-1
10-2
mgluino (TeV)
1
10
mgluino (TeV)
With the today precision
we do not have 3s exclusion
for any set of parameters
Some final considerations
Flavour Physics is now in mature age.
Many measurements have been performed
and many new we will discuss at this
conference. Some stringent test of SM
has been done (sin2b, Dms…)
It is a very active an lively field with many new results :
highlight D0 mixing !!
Our goal is to find NP or to measure the parameters of NP.
Quite a lot of work has been done
More we need to to..
For it we need :
Precise measurements (at 1%)
Precise theory (Lattice calcs at 1%)
We need to go on in measuring precisely many different quantites
ACP(BXg)
AFB(BXll)
CPV in CF and DCS D decays
Br(tmg)
……
Could be a nightmare….
Adjusting the central values so
that they are all compatible
CKM angles a,b,g
Br(Btn) and B Dln
|Vub|,|Vcb|
radiative decays : Br(Brg, K*g)
many other measurements…
..but I’m sure it will be a dream !!
Keeping the central values as
measured today
BACKUP
MATERIAL
An example on how to fit the UT parameters and fit new physics
bcℓn
B
Bccs
and
and
B: sdecays
f:mixing
/b
: f2/a
BDK
dBpp/rp/rr
1fbuℓn
eK : CPV
in K
3/g
B0  D0 h0
Together with
J/y Kp , D*D*K
Help in distinguishing between the
two b solution from sin2b measurement
S  +0.56  0.23  0.05
C  0.23  0.16  0.04
Many novelties on the measurement of the angle a
pp modes
Not only “Tree” diagrams contribute to
final states but also “Penguins”.
Isospin analysis necessary to extract a
rr modes
Br (B  r 0 r 0 )  (1.07  0.33  0.19)  106
3.5s evidence
Important measurement because it gives
the contributions of Penguins diagram
consistent with no CP violation
aeff~90o (0/180)o
New results also on rp (time dep. Dalitz analysis)
The angle g : still quite a lot of work to do…
Most precise measurement come
from Dalitz analysis with D0Kspp
x  rB cos(
g)
y  rB sin( g )
rB 
A(B   D 0K  )
0
A(B   D K  )
critical the value of rb
Babar more precise than Belle on x,y
but found a smaller rB larger error on g
g  (92  41stat  10syst  13Dalitz )o
BaBar
o
g  (53+15

3

9
)
18 stat
syst
Dalitz
Belle
New D0 decay explored
BaBar
g  (25  48)o
g  (82  20)o
rB  (0.075  0.030)
Precision measurements of |Vcb|
Essential point is
to control /“measure”
the effects of strong
interaction
Inclusive Vcb still progress…
Same for exclusive..
BD*ln
(Babar)
Vcb  (41.93  0.65 fit  0.07as  0.67theo . )10 3
mb  (4.564  0.076 fit  0.003as )GeV
mc  (1.105  0.116 fit  0.005as )GeV
here we extract : F (1) Vcb
limiting factor F(1)
Brcln  (10.590  0.164 fit  0.006as )%
BaBar/CLEO/CDF/DELPHI
Kinetic scheme
3
Vcb  (41.96  0.23fit  0.35as  0.59theo. )10
Study on charm sector help in
the understanding of strong dynamics
Radiative B decays : moving beyond BK*g
- many measurement on Bsg
- measurements of Br on Bg
- measurement of ACP on
exclusive and inclusive modes
B0  r 0g
Are there evidence of disagreement in the actual fit ?
agreement between the predicted values and the measurements at better than :
1s
3s
5s
2s
4s
6s
No disagreement for g et Dms
SM Fit
t
o
d
a
y
L
H
C
b
(δ )
dij
diA
AB
NP scale at 350 GeV
dBj
Im ( d 23 )
LL
Due to the actual disagreement
betweenVub and sin2b we see a
slight hint of new physics
Im ( d 23 )
Re (d13)LL vs Im (d13)LL
superB if disagreement
disapper.
LL
Re ( d 23 )
SM
Im ( d 23 )
Re ( d 23 )
Constraint from Dmd
Constraint from sin2b
LL
LL
Re (d13)LL vs Im (d13)LL
with
present disagreement
LL
Constraint from sin2b cos2b
All constraints
Re ( d 23 )
NP at
high significance !
LL
MSSM
~
g
With the today precision
we do not have 3s exclusion
~
b
b
( )
d
~
s
s
New Physics contribution
(2-3 families)
23 LR
|  23 |LR
| 13 |LL
1
1
In the red regions the 
are measured with a
significance >3s away
from zero
10-1
10-1
10-2
mgluino (TeV)
1
mgluino (TeV) 10
mgluino (TeV)
1
10
In this case the main
constraints are bsg
Today we would have
magenta contour covering all the space
Im ( d 23 )
LR
ACP(bsg)
Re ( d 23 )
LR