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Introduction to Heavy Flavour Physics (..more on CKM and CP violation). Achille Stocchi (LAL Orsay/IN2P3-CNRS Universit é Paris-Sud). in 25 minutes. Short introduction. Main motivations. Selection of new measurements. The present situation. How and why.. to go on…. Short Introduction. - PowerPoint PPT Presentation
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B → τ ν
(B→ρ/ω γ)/(B→K*γ)
Moriond QCD17 -24 March 2007 La Thuile, Italy
Achille Stocchi(LAL Orsay/IN2P3-CNRS
Université Paris-Sud)
Introduction to Introduction to Heavy Flavour PhysicsHeavy Flavour Physics
(..more on CKM and CP violation)(..more on CKM and CP violation)
Short introduction. Main motivations
Selection of new measurements
How and why.. to go on…
The present situation.
in 25 minutes
Short Introduction.Main Motivations
Flavour Physics in the Standard Model (SM) in the quark sector:
10 free parameters
6 quarks masses 4 CKM parameters
~ h
alf
of th
e St
anda
rd M
odel
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
Wolfenstein parametrization : ,A,responsible of CP violation in SM
B
+other charmonium
radiative decays Xs,Xd, Xsll
B DK
+from Penguins
The Unitarity Triangle:
Charm Physics(Dalitz)
?
theo. clean
the angles..
sin(
sin(
BB
the sides...
Rare decays...sensitive to NP
ms md Vub/Vcb
CP asymmetries in charmless
…
How measurements constraint UT parameters
From Childhood
In ~2000 the first fundamental test of agreement betweendirect and indirect sin2
To precision era
WE HAVE TO GO ON…
To access the parameters of the Standard Model we need to control the effects induced by strong interactions
We observe hadrons and not quarks ! theory gives us the link from quarks to hadrons OPE /HQET/Lattice QCD …. Need to be tested !
Before starting…
Decay properties and production characteristics
Lifetimes
Masses (spectroscopy)
Form factors
Branching ratios
Many measurements ( with different weights ) are essential
beauty and charm physics are equally important
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
B0
B0
fCP
A1
A2
A1
A2
M12
12
direct
mixing
Inter
fere
nce
mix
ing-
deca
y
Direct also with B+
source 1A
2A
In the double-slit experiment, there are two paths to the same point on the screen.
1A
2A
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.
Analogy: “Double-Slit” Experiments with Matter and Antimatter
The precision on sin2 is still improving..
b
d
c
csd
J/
K0
B0d
0
sin2f
f CP
C
S
~only one amplitude
theoretically cleanat ~0.01
To improved with data!
0.678 0.026 0.002 0.021
( ) cos sinCPff d f da t C m t S m t
t(ps) t(ps)
direct indirect
sin2 gives the best constraint on plane
sin(
d d
sb
W
B0d
t s
s
K0
g
sb b s
~
~ ~
New Physics contribution (2-3 families)
LRd
23
sin2 from “s Penguins”…a lot of progress..
“CP violation observed in ’Ks”
Disagreement between sin2 from bccs and bqqs
still there and intriguing..
Some discrepencies observed between Vub and sin2
sin2 =0.764± 0.039from indirect determination
(all included by sin2)
sin2 =0.764± 0.039from indirect determination
(all included by sin2)
sin2=0.675±0.026From direct measurementsin2=0.675±0.026
From direct measurementWe should keep an eyes on these kinds
of disagreements. Could be NP
Br ~ |Vub|2 in a limited space phase region…
Using Babar El, (Xs
El
Progress on Vub..
Inclusive : improving analyses and improving the control of the theory vs cuts
untagged analysisis the most precise
Exclusive : we start to have quite preciseanalysis of Br vs q2
Important that we measure at high q2 where LatticeQCD calculates better.
B l B Xu l
Confirming disagreement…
LEP/SLD 1999LEP/SLD 2002CDF 2006
SM predictionsof ms
CDF only : signal at 5
Strong impact on NP on Bs sector. See laterLimiting factor : precision on the hadronic parameter
))1(( 2222
2
ss
dd
BB
BB
s
d
Bf
Bf
m
m
A Milestone :the meaurement of the
Bs oscillationsafter a long saga..
-0.21
0.42 -10.21
-1
17.33 0.07 ps
0.507 0.004 pss
d
m
m
ms md
BR(B → τ ν) = (0.85 ± 0.13)10-4
fB = 237 ± 37 GeV from exp+UTfit
fB = 189 ± 27 GeV Lattice QCD
SM expectation
Exp. likelkihood BABAR+BELLEBR(B → τ ν) = (1.31 ± 0.48)10-4
A second milestone :the measurement of the leptonic decay B
First leptonic decay seen on B meson
Mixing in D0 -D0 system Observed !! BaBar
cossin' yxy sincos' yxx
2
, ym
x
Use D0 from D* to tag the flavour of D0
D*+ D0 +
'yRRR DCSDCSWS
2
0
2'2'
0'
2
0
0
)(2)()(/
)(/)(
D
tyx
D
tyRR
tDK
tDKtR DCSDCSWS
DCS decays
Interference Oscillations(1 ± cosm t) ~ x2/2 idem for ~ y2/2
D0
D0
K
mixing
doub
l y C
abi b
bo s
u ppr
ess e
d(D
CS )
Cabib
bo fa
vour
ed(C
F)
Wrong sign : WS
strong phase CF/DCS ampl.rotation (x,y)(x’,y’)
mixingno mixing
3' (9.7 4.4 3.1) 10y
no mixing
'2 3( 0.22 0.30 0.20) 10x
3.9 evidence
Submitted to PRL (hep-ex/0703020)
2.4
Method using Dalitz ex : D0 K0S
RS and WS occupy the same Dalitz plot Measurement of strong phase Constraint on x,y2
( also sensitive to sign of x)
1)()(
)(
2
orKK
K
KK+ (or ) pure CP D10
K 50% D10 + D2
0
Constraint on y
CP eingenstate lifetimes
Two talks tomorrow+theory talk….
Belle :
Compare assuming =0: (x'=x, y'=y)
Best fit
Within 2less if 0
Belle life. (1)
ALL is very exciting. D mixing isNow observed, we need more
Measurements with different techniquesto get x and y parameters.
Belle Dalitz
fDs, FD from CLEO-C
Semileptonic D decays. example DK l
Precise measurement, test of the QCD calculation on charm sector Could be used on B sector : , Vub..
Testing lattice QCD on charm sector : form factors
D
The present situationHow 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
= 0.344 ± 0.016 = 0.344 ± 0.016 = 0.163 ± 0.028 = 0.163 ± 0.028
md,ms,Vub,Vcb,k + cos2 + + + + 2+
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 ~ 0.5, 1…1016 TeV
The quantum stabilization of the Electroweak Scalesuggest that ~ 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 NPflavour structure of the NP - we can explore NP scaleNP scale beyond the LHC reach
f
bq
e f
5 new free parameters Cs,s Bs mixing
Cd,d Bd mixing
CK K mixing
Today : fit possible with 10 contraints and 7 free parameters (Cd,d ,Cs,s, CK)
Con
stra
ints
Parametrizing NPphysics in F=2 processes
2 2 2
2
d
NP
q
SMi B B
SMB
CQ Q
eQ
F=2Fit in a NP model independent approach
0( / ) sin(2 2 )
| | | |
EXP SMd q d
CP d
EXP SMd
EXP SMK K
m C m
A J K
C
Cd d Cs s CK
D X
Vub/Vcb X
md X X
ACPJ X
X
ASL X X
X X
ACH X X X X
ss X X
ms X
K X X
In future :
ACPJ ~X X
ASL(Bs) X X
DsK) X
Treeprocesses
13 family
23 family
12 familiy
No new physicsC=1 =0
Model Indep. Analysis in B=2
C = 1.24 ± 0.43 = (-3.0 ± 2.0)o
C = ± 0.031 = (± 0.5)o
2 2 2
2
d
NP
q
SMi B B
SMB
CQ Q
eQ
Factor 3-4 gain on NP scale
if SuperB
NP scale ~200GeVwith MFV couplings
Similar plots in Bs sector where the impact of LHCb is crucial
NP~700 GeV
Precision will be enough to have 5discrepancy with todaycentral values In some more favourable case
MH
(TeV
)
tan
In the red regions the are measured with a
significance >3 away from zero
23| |LR
(TeV)gluinom 1 10
g
sb b s
~
~ ~ New Physics contribution (2-3 families) LR
d23
With the today precisionwe do not have 3 exclusion
for any set of parameters
(TeV)gluinom
MSSM
1
10-1
10-2
Example on how precise measurementscould allow to explore NP scale
beyond the TeV scale
Some final considerations
Flavour Physics is now in mature age. Many measurements have been performedand many new we will discuss at this conference. Some stringent test of SM has been done (sin2, ms…)
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%)
It is a very active an lively field with many new results : highlight D0 mixing !!
We need to go on in measuring precisely many different quantites
ACP(BX)AFB(BXll)CPV in CF and DCS D decaysBr()……
CKM angles randDl|Vub|,|Vcb|radiative decays : Br(B, K*)many other measurements…
..but I’m sure it will be a dream !!
Keeping the central values as measured today
Could be a nightmare….
Adjusting the central values so that they are all compatible
BACKUPMATERIAL
bcℓ and buℓ Bd and Bs mixingK : CPV in K decaysBccs : 1 /B// : 2/BDK : 3/
An example on how to fit the UT parameters and fit new physics
B0 D0 h0
0.56 0.23 0.05
0.23 0.16 0.04
S
C
Together with J/ K , D*D*K
Help in distinguishing between thetwo solution from sin2 measurement
modes
0 0 6( ) (1.07 0.33 0.19) 10
3.5 evidence
Br B
modes
consistent with no CP violation eff~90o (0/180)o
Many novelties on the measurement of the angle
New results also on (time dep. Dalitz analysis)
Not only “Tree” diagrams contribute to final states but also “Penguins”.
Isospin analysis necessary to extract
Important measurement because it givesthe contributions of Penguins diagram
The angle : still quite a lot of work to do…
critical the value of rb
Babar more precise than Belle on x,ybut found a smaller rB larger error on
cos( )
sin( )B
B
x r
y r
0
0
( )
( )B
A B D Kr
A B D K
1518
(92 41 10 13 ) BaBar
(53 3 9 ) Bellestat
ostat syst Dalitz
osyst Dalitz
Most precise measurement come from Dalitz analysis with D0Ks
New D0 decay explored
(25 48)o
BaBar
(82 20)o (0.075 0.030)Br
Precision measurements of |Vcb|
limiting factor F(1)
3.(41.93 0.65 0.07 0.67 )10
(4.564 0.076 0.003 )
(1.105 0.116 0.005 )
(10.590 0.164 0.006 )%
s
s
s
s
cb fit theo
b fit
c fit
cl fit
V
m GeV
m GeV
Br
Inclusive Vcb still progress…
3
.(41.96 0.23 0.35 0.59 )10scb fit theoV
BaBar/CLEO/CDF/DELPHI Kinetic scheme
(1) cbF Vhere we extract :
BD*l
Essential point isto control /“measure”the effects of strong
interaction
Same for exclusive..
Study on charm sector help in the understanding of strong dynamics
(Babar)
Eve
nts/
0.5
0 0B
Radiative B decays : moving beyond BK*
- many measurement on Bs- measurements of Br on B- measurement of ACP on exclusive and inclusive modes
No disagreement for et ms
Are there evidence of disagreement in the actual fit ?
agreement between the predicted values and the measurements at better than :
6
5 3
4
1
2
SM Fit
today
LHCb
Re (d13)LLvs Im (d
13)LL
with present disagreement
Constraint from md Constraint from sin2cos2
Constraint from sin2 All constraints
Re (d13)LLvs Im (d
13)LL
superB if disagreement disapper.
iAd j
Bd dijδ
AB
SM
Due to the actual disagreement betweenVub and sin2b we see a slight hint of new physics
NP at high significance !
NP scale at 350 GeV
23Re d
LL
23Im d
LL
23Im d
LL
23Im d
LL
23Re d
LL
23Re d
LL
In the red regions the are measured with a
significance >3 away from zero
13| |LL
1 10
1
10-1
23| |LR
(TeV)gluinom
1 10
g
sb b s
~
~ ~New Physics contribution (2-3 families)
LRd
23
With the today precisionwe do not have 3 exclusion
(TeV)gluinom
MSSM
(TeV)gluinom
1
10-1
10-2
In this case the mainconstraints are bs
ACP(bs)
Today we would have magenta contour covering all the space 23Re d
LR
23Im d
LR