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