Enorme quantita’ di risultati presentati

piu’ di 300 articoli sottomessi a EPS e Lepton-PhotonPer un report e’ ovviamente necessario fare una severa selezione

Highlights from summer conferences

L. Bellagamba (INFN Bologna)

• WMAP: towards a high-precision cosmology• Dark matter: DAMA result

• News from CP violation in the b-sector• EW tests: possible disagreements with SM expectations

- NuTeV result- sin2θθW from forward-backward/left-right asymmetries- (g-2)µµ

OverviewNon accelerator physics

Gruppo I physics

-Disomogeneity 1/100000 (COBE beginning ‘90)

Important discovery: first observations of CRB anysotropies

- Disomogeneity 1/1000dipole due to Doppler effect

WMAP: towards a high-precision Cosmologystudying the cosmic radiation background (CRB)

At first sight CRB is isotropic

Looking to details:T=2.73 K

The Cosmologic Principle states that Universe is isotropic and homogenous at large scaleThis was confirmed by the first CRB observations (Penzias e Wilson 1965)

Recent results from WMAP

CRB patternsnapshot of theUniverse at the decoupling time

1. Gravity fluctuations acts on baryon-photon gasoscillation (compression – rarefaction) due to gravity and

pressure of the plasma

Where the CRB pattern come from ?

2. At the decoupling time the photons are released (the Universe become trasparent)

Compress the CMB map to study cosmology

δT (θ,ϕ ) == a lmYlm (θ ,ϕ )l ,m∑∑

Express sky as:

C l ==1

2 l ++1alm

2

m

∑∑

5 degrees

all the statistical information is contained in the angular power spectrum

Fit of the cosmological parameters

Age of Universe:13.4 ±± 0.3 Gyr

Age at decoupling:372 ±± 14 Kyr

Baryon density:0.047 ±± 0.006

Matter density:0.29 ±± 0.07

Before (11 feb. 2003)

WMAP

Fundamental mode

Primordial ripples

compressionrarefaction…

Geometry

baryons

Using a flat Universe(6 parameters)Acceptable χχ2

1.02 0.02mΛΩ = Ω + Ω = ±Flat within errors

Verde et al 2002Galactic clusters

Removing the flat condition in the modelImprovement precision respect to previous results (Boomerang)Using also results from SN 1A and galactic clusters

strong constraints on ΩΛ and Ωm

Geometry of the Universe

Riess et al. 2001Extragalactic SN 1A

We (and all of chemistry) are a small minority in the Universe

Now the question is:What are Dark Matter and

Dark Energy?

Dark matter properties WIMPsDark matter natural candidate: LSP in Rp conserving SUSY

LSP in the MSSM is the lightest neutralino:

3 0 01 2 3 1 4 2a B a W a H a Hχ = + + +

Neutral gauginos Higgsinos

elastic scattering off a target nucleus:- cross section depends on the relative velocity between WIMP and target- the nuclear recoil energy is the measured quantity.

Direct detection in underground experiments

- Very low energy : ER ∼ 10 keV- Very small interaction rate : down to ∼ 10-5 c/kg/day

Dark matter (I)

See annual modulationsignal (hearthorbital motion)Effect ≈ 5-7%

100 kg NaI(Tl) detector mass (scintillation)

Dark matter (II)

~30 km/s

60 °

~220 km/s

Jun

Dec

Sun

Earth

Latest results astro-ph/0307403(7 annual cycles)58000 + 49800 = 107800 Kg.days

DAMA experiments at Gran Sasso claims model independent evidence for WIMPS in the galactic halo

Allowed region for spin independent coupled WIMPS considering few different halo models and different values for the local WIMP velocity (170-270 Km/s)

Isotropic halo and dispersoin velocity

NaIAD 2002 (new 25 kg.yrs)

UK/Boulby : NaIAD (NaI) x-check for DAMAUK/Boulby : ZEPLIN (Liq.Xe)Stanford : CDMS (Ge e Si)Frejus, France : EDELWEISS (Ge)

Dark matter (III)Other experiments:

RemarksComparison between different exps. extremely difficultDifferent targets can result in very different cross sections

Number of counts other expts. could expect on the basis of DAMA modulation results varies from few to zero.

DAMA new

The precision CMB studies opens a new era for CosmologyWe are close to a Standard Cosmology able to fit a large number of observationsActivity is going on:- polarization study on WMAP data still going on

possible discrimination between different inflation models - new satellite (Planck) will be launched in 2007

SUSY, offering a natural DM candidate, contributed to strengthen the link between high-energy physics and Cosmology.The detection of WIMP/LSP in underground detector is an extremely difficult task at the limit of the present technology. The techniques are anyway going better and better.Can we discover first sparticle before LHC ?DAMA already claimed to have it, but it is not a direct evidence and an independent check, also considering the difficult of the measurement, is certainly required.

Summary of the cosmological section

New Physics in B →→ ΦΦ Ks ?CP violation in the b sector:• B → J/ψ Ks dominated by a tree-level amplitude

bc

csW

J/ψ

K:

Hint of new physics in B →→ φφ K ?(NP effects might be large in loop induced processes)

Belle (2003) 140 fb-1 :BaBar (2002) 81 fb-1 :

sin(2ββ) =0.733±0.057±0.028sin(2ββ) =0.741±0.067±0.033

Closer to SM respect to previous results

Belle 2003: sin2ββeff = -0.96 ±0.50Belle result 3.5ó off respect to SM

2.1 σ between BaBar and Belle: more data absolutely needed to clarify the situation

BaBar 2003: sin2ββeff (ö KS) = +0.45±0.43±0.07

NEW: MW(Aleph) lower, small shiftsin heavy flavors, atomic PV close to SMnew Mt D0 Run I and CDF Run II not included

OVERALL SM fineexcept for NuTeV

Fit:MH=96 GeV, MH<219 GeV at 95%CL÷2/dof=25.4/15 4.5% prob

without NuTeVMH=91 GeV, MH<202 GeV at 95%CL

÷2/dof=16.8/14 26.5% prob

Global EW fit

NuTeV main new feature is having both ν and ν beams

Independent measure of sin2θ using νν/νν NC/CC cross sections exploiting the PASCHOS-WOLFENSTEIN ratio

Most uncertainties and O(αs) corrections cancel in the PW ratio

Corrections needed for:

non isoscalar target (2Z≠≠A), ννe in the beam, higher twist, radiative corrections, effects of flavour asymmetries in the pdfs

-

The NuTeV result (I)NuTeV at FERMILAB measures NC/CC cross sections in ν DIS

-

0

0

NNC

NNC

rν

ν

σσ

≡0 0

0 0

2 22

2n

1

1si

N NNC NC

PW N N WR

C

L

C CC

R r RR

rg g

ν ν

ν νν ν

θσ σ

σ σ

− − ⋅ = = = = −− −

−

0

0

/

/ /

NNC

NCC

Rν ν

ν ν ν ν

σσ

=

sin2θθw(NuTeV)=0.2276±0.0013stat ±0.0006syst ±0.0006th-0.00003(Mt/GeV-175)+0.00032 lnMH/100GeV

sin2θθw= 0.2229 ±0.0004

~ 2.8 σσ

NuTeV works at LO in QCD and finds

Global EW fit:

The NuTeV result (II)

Dalla misura separata di Rνν, Rνν

2Lg

2Rg i

NuTeV suggests a smaller left-handed coupling

i

( )1PW sR u d c s O α− − − − ∆ ∝ − + − + ( ) ( )

1 _

0

q x q x q x dx− = − ∫Isospin violation

( ) ( )P Nu x d x≠Strange asymmetry

New MRST fit confirms such estimation but very large uncertainties

NuTeV finds much smaller effect

(III) NuTeV result O(1%) effectpossible SM explanations related to hadronic structure

A positive s- reduces the anomalyNaturally of O(1%), δδs2W ≈≈ 0.002

Different models give this order of magnitude, δδs2

W<0

mH = 500 GeV

Sather,Rodionov et al,Londergan&Thomas

Discrepancy reduced ~ 30% i

( ) ( )s x s x≠

0.002sδ − =

NuTeV (IV) Strange Asymmetry

- relies on inconsistent parameterization (total strangeness S ≠ 0)- does not fit s- in the context of global fit

Recall: positive s- reduces the NuTeV anomaly

• NuTeV: Dimuons (charm production)s-=-0.0027±0.0013 (low x) BUT NuTeV fit to s-

• New CTEQ fit- includes all available data- accounts for strangeness conservation (S=0)- fits s,sbar together with other pdfs

Negative s- strongly disfavoured, acceptable fits have 0.001< s- <0.0031

Final remarks:Few issues still open: large sea uncertainties and shift from s- could reduce discrepancy below 2óGiven present understanding of hadron structure, RPW is no good place for high precision physics

2 22 Vf Af

fVf Af

g gA

g g=

+

Asymmetries at the Z pole (I)Problem: ~3ó discrepancy between LR asymmetry of SLD and FB b asymmetry of LEP: in SM they measure the same quantity, sin2èeff

, , , , 3

4F L B L F R B Rpol

FB ftot

A Aσ σ σ σ

σ− − +

= =

SLD: Z with beam pol.L R

LR etot

A Aσ σ

σ−

= =

0, 3

4f F B

FB e ftot

A A Aσ σ

σ−

= = (e,µ,τ,c,b)

, , , ,F R B R F L B Lpol f

tot

A Aσ σ σ σ

σ+ − −

= =(τ)

LEP: Z→ff

, , , , 3

4F R B R F L B Lpol

FB etot

A Aσ σ σ σ

σ− − +

= = −

New AFB(b) preliminaries from OPAL and DELPHI

2 possibilities, both involving new physics:- AFB(b) points to new physics- it’s a fluctuation or due to unknown syst.

In case, it is possible to find NP that mimics a light Higgs. For example SUSY can do that with light sleptons, tanâ>4

Altarelli et al

without AFB(b) , the MH fit is very goodMH=42 GeV, MH<120 GeV at 95%CL

Asymmetries (II)The Chanowitz argument

But it is AFB(b) which pushes Higgs mass up !

but in conflict with direct lower bound MH>114.4 GeV

Conclusion is sensitive to top massimprovement precision of Mtop is the priority Tevatron II

(g-2)µ news (I)

No experimental news: BNL g-2 experiment latest result from 2000 µ+ datareleased 2002 :

soon result of 2001 µ−dataexpected 30% error reductions

Excellent place for new physics unexplored loop effects ~ m2µ/Ë2

but needs chiral enhancementSupersymmetry is natural candidate at moderate/large tanâ

Some theory developments:

4loop big, never checked!

( ) 10- 2 / 2 11659203(8) 10a gµ−= = ⋅

LxL changeof sign

Revised CMD-2

CMD-2

Incomplete compilation of theory predictionsEidelman-Jegerlehner,Davier et al,Hagiwara et al

Vacuum polarization integrals involve vector spectral functionswhich can be experimentally determined from two sources:- e+e- annihilation cross section (CMD-2)- Hadronic tau decays (ALEPH, CLEO, OPAL)

(g-2)µ news (II)Largest theoretical uncertainties from

aµµhad,LO

Hagiwara et al (HMNT) NEW result:a ì

had,LO=691.7±5.8exp±2.0r.c.

Final CMD-2 ð ð data (2002) 0.6% syst error!CMD-2 have recently reanalyzed their data

~ 2-2.5ódepending on which e+e- analysis

Davier at al (DEHZ)a ì

had,LO=709.0±5.1exp±1.2r.c±2.8SU(2)

Good agreement between Aleph, CLEO, Opal ôdata

Agreement with exp. results

Tau datae+e- data

(g-2)µ news (III)

e+ e-

ð- ð+

ã

ô- í

ð- ð0

W

CVC + isospin symmetry Corrections by Cirigliano et al 02

ISR reduces the effective energy of the collision: even e+e- colliders at fixed energy can investigate range of s profit of large luminosities of meson

factories (DAΦNE, CLEO-C, BaBar, BELLE)

- interesting NEW results from KLOE (e+e- → ππ in the region 0.37 < sð <0.93 GeV )

äa ì(had)=374.1±1.1stat±5.2syst±2.6th+(7.5-0.0)FSR

- to be compared with the NEW CMD-2 (same s range)äa ì(had)=378.6±2.6stat±2.2syst&th (it was 368.1)Discrepancy with τ data confirmed by KLOE

Possible violation of CVC or isospin symmetry? - KLOE is soon expected to improve the

precision- BaBar is finalising similar analysis- Maybe new inputs will come from BELLE

Further understanding needed

SM works fineDespite the severe tests performed in the attempt to discover some sign of new physicsno really convincing BSM signal so far

There are few points to clarify that will be further investigated in the next future

One of the next future priority is certainly improving the top mass precision.A routine job for TEVATRON II but fundamental to better understand the few obscurities of the SM and eventually to discover the first convincing signs of new physics.

SM status summary

• WMAP: towards a high-precision cosmology• Dark matter: DAMA result• News on solar νν oscillations

• News from CP violation in the b-sector• EW tests: possible disagreements with SM expectations

- NuTeV result- sin2θθW from forward-backward/left-right asymmetries- (g-2)µµ

• Single top production: example of complementarity between different colliders

OverviewNon accelerator physics

Gruppo I physics

FCNC couplings involving the top quark ?Anomalous couplings between top, γ/Z and u/c may arise in SM extensions

• single top production @ LEP & HERA• t → u/c + γ/Z @ Tevatron

• not excluded by LEP & Run I data• ZEUS vs H1 : too few events so far…

→ looking forward to doubling L !

H1 Prelim., Contrib. Paper #181ZEUS Collab., PLB 559, 153 (2003)Final DELPHI results, Contrib. Paper #53L3, PLB 549 (2002) 290

H1 : 5 candidates, 1.7±0.4 expected (Prelim.)

Sensitivity @Tevatron :• mainly via radiative top decays• u/c γ → t : σ quite large but huge bckgd !

ZEUS Collab., PLB 559, 153 (2003)

ktuγγ

HERA events with isolated lepton + PT,miss (I)

µµ

jet

ep

e p → µ + jet + X e p → τ + jet + X

HERA events with isolated lepton + PT,miss (II)- No excess in H1 e- p data- No excess in ZEUS data in e & µchannels, τcandidates- Agreement in the had. channel (but large bckgd)- W prod full NLO corrections included

(recently available)

e p → l + jet + PT,missMain SM contribution :

1 / 0.06 ±± 0.01PTX > 40 GeV

2 / 0.12 ±± 0.02PTX > 25 GeV

ττ channelZEUS e±± p data

ZEUS Prelim

ττ →→ had130 pb-1

σ(W)~1pb

6 / 1.08 ±± 0.223 / 0.55 ±± 0.123 / 0.54 ±± 0.11PTX > 40 GeV

10 / 2.92 ±± 0.496 / 1.44 ±± 0.254 / 1.48 ±± 0.25PTX > 25 GeV

Combined e & µµµµ channel e channel H1 e+ p data

e & µe & µ

H1 e+ p data, 105 pb-1

H1 Collab., PLB 561, 241 (2003)

Descrizione del fit

Flat LCDM still fits

Fits not only the CMB but also a host of other cosmological observations.

The simplest best fit model has 6 parameters and

χ 2

ν==

1431

1342== 1.07

The probability to

exceed is 5%

Can combine data with external surveys as well.

Baryon density Ωbh2 0.024 ± 0.001Matter density Ωmh2 0.14 ± 0.02Hubble constant h 0.72 ± 0.05Amplitude A 0.9 ± 0.1Optical Depth τ 0.166 + 0.076 – 0.071Spectral index ns 0.99 ± 0.04

02.002.1 ±=ΩVerde et al 2002

WMAP TE data in bins of Äl=10

Primordial Adiabatic i.c.

Causal Seed model (Durrer et al. 2002) Primordial

Isocurvature i.c.

Flat within errorsImprovement precisionrespect to BoomerangUsing also results from SNand galactic clusters

strong constraints onΩΛ and Ωm

Geometry

Preliminary studies

Anti-correlationTemperature-polarization

Data supports inflationTo some extent is possible to discriminate among different models

Riess et al. 2001

Beauty production at HERA

- Previously reported anomalies from HERA TEVATRON and LEP

Phot.

DIS

- b tagged exploiting semileptonicdecay b → cµµUnfold from charm, uds using δδ(Si) and Pt

rel (µµ-jet)

- Compare with NLO QCD directly in measured rangeZEUS results in quite good agreement with SM predictions H1 photoproduction a bit above

- Larger statistics with HERA II data in the next futureb-tagging also will profit of the detectors upgrading in the vertex region

CP violation in SM due to a complex phase in CKM matrixB-factories allow precise measurements in b-sectorand explore possible beyond SM sources of CPV

Belle : sin(2ββ) = 0.99±0.14±0.06

Babar : sin(2ββ) = 0.59±0.14±0.05

Belle (2003) 140 fb-1 :

BaBar (2002) 81 fb-1 :

Updated results:

sin(2ββ) =0.733±0.057±0.028

sin(2ββ) =0.741±0.067±0.033

CPV news (I)

Really going towards a precise measurement

K (εk) and B (∆md,Vub , Vtd , sin (2β)) sectors consistent with each other and SM

ρρ

ηη

• B → J/ψ Ks dominated by a tree-level amplitude

- 2001 first signals for CPV outside of the kaon sector

bc

csW

J/ψ

K

DAMA experiments at Gran Sasso claims model independent evidence for WIMPS in the galactic halo

See annual modulation signal (hearth orbital motion)

100 kg NaI detector mass (scintillation)

- First results (2002) based on58000 kg-days exposure (4 years)

Mχ χ ~ 52 GeVσσp ~ 7x10-6 pb

- Latest results astro-ph/0307403(3 more annual cycles)58000 + 49800 = 107800 Kg-days

Dark matter (II)

CPV news (II)Search for New Physics in rare B-decays

In the SM

Theoretically cleanest example:

BaBar 2003: sin2ββeff (ö KS) = +0.45±0.43±0.07Closer to SM respect to previous results

Belle 2003: sin2ββeff = -0.96 ±0.50Belle result 3.5ó off respect to SMCurrent WA: sin(2ββ)=0.731±0.056

sin(2β)eff = sin(2β) (Bà φφ KS )

But 2.1 σ between BaBar and Belle: more data absolutely needed to clarify the situation

E158 (SLAC) new results for PV in Moller scattering

• suppressed at tree level• sensitive to sin2θ• sensitive to new physics complementary to collider exps.

Results in agreement with SMsin2θθeff(Q2=0.027 GeV2)=

0.2371 ±± 0.0025 ±± 0.0027

Soon results from Run IILast run (III) is going very well

Final results next year

Huge luminosityHigh polarization (~80%)

HERA multilepton eventsSearch for events with several leptons in final stateMainly produced via γγ collisions

0 / 0.37 ±± 0.043 / 0.23 ±± 0.043e, M > 100 GeV2 / 0.77 ±± 0.083 / 0.30 ±± 0.042e, M > 100 GeV

ZEUS ( 130 pb-1)H1 ( 115 pb-1)selectionexpt

(different angular ranges in H1 / ZEUS analyses)

observed / expected

3e2e+3e

H1, hep-ex/0307015, submitted to Eur. Phys. J

M12(GeV)

Solar νν news

• SNO, (April 2002)

ΦΦSSM=5.05+1.01-0.81

ΦΦSNO=5.09+0.44-0.43

+0.46-0.43

106 cm-2 s-1

• KamLAND (December 2002)observed evidence for reactor neutrino disappearence at ~ 180 Km distance

LMA

SMA

LOW

VAC

Assuming CPT only LMAsolution compatible with deficit observed by KamLANDBest fit (thres. 2.6 MeV):sin22θθ=1.0∆∆m2=6.9 10-5 eV2

Solar neutrinos not a problem anymore:

Predicted region at 95% CL from solar nu expts assuming LMA

MNSP matrix

Atmospheric, K2Kθθ23~450

Solar, KamLANDθθ12~300

Accelerator, reactorθθ13 not measured yet

νν physics is certainly the sector with the most impressive developments in the last few years.-In this sector we discovered the only BSM physics so far, even if a natural extension of the SM can accommodate νν masses and mixing.- the old solar νν problem, which tormented us since 60’, has been finally understoodIn the next few years accelerator and reactor experiments will give insight on the still unmeasured mixing angle and, hopefully, the first “appearance” signal will give us the direct evidence that ν do oscillate.

Summary on ν