Highlights from summer conferences
1 / 39

Enorme quantita’ di risultati presentati piu’ di 300 articoli sottomessi a EPS e Lepton-Photon - PowerPoint PPT Presentation

  • Uploaded on

Highlights from summer conferences. L. Bellagamba (INFN Bologna). Enorme quantita’ di risultati presentati piu’ di 300 articoli sottomessi a EPS e Lepton-Photon Per un report e’ ovviamente necessario fare una severa selezione. Overview. Non accelerator physics.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Enorme quantita’ di risultati presentati piu’ di 300 articoli sottomessi a EPS e Lepton-Photon' - ismail

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Highlights from summer conferences

L. Bellagamba (INFN Bologna)

Enorme quantita’ di risultati presentati

piu’ di 300 articoli sottomessi a EPS e Lepton-Photon

Per un report e’ ovviamente necessario fare una severa selezione


Non accelerator physics

  • 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

    • - sin2qW from forward-backward/left-right asymmetries

    • (g-2)m

Gruppo I physics

Recent results from WMAP

WMAP: towards a high-precision Cosmology

studying the cosmic radiation background (CRB)

The Cosmologic Principle states that Universe is isotropic and homogenous at large scale

This was confirmed by the first CRB observations (Penzias e Wilson 1965)

At first sight CRB is isotropic

T=2.73 K

Looking to details:

- Disomogeneity1/1000

dipole due to Doppler effect

  • Disomogeneity1/100000

  • (COBE beginning ‘90)

  • Important discovery: first observations of CRB anysotropies

Where the CRB pattern come from ?

  • Gravity fluctuations acts on baryon-photon gas

  • oscillation (compression – rarefaction) due to gravity and pressure of the plasma

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


snapshot of the

Universe at the

decoupling time

Compress the CMB map to study cosmology

5 degrees

Express sky as:

all the statistical information is contained in the angular power spectrum





Before (11 feb. 2003)

Primordial ripples

Fundamental mode


Fit of the cosmological parameters

Using a flat Universe

(6 parameters)

Acceptable c2

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

Flat within errors

Geometry of the Universe

Removing the flat condition in the model

Improvement precision respect to previous results (Boomerang)

Using also results from SN 1A and galactic clusters

strong constraints on WL and Wm

Riess et al. 2001

Extragalactic SN 1A

Verde et al 2002

Galactic clusters

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 (I)

Dark matter properties WIMPs

Dark matter natural candidate: LSP in Rp conserving SUSY

LSP in the MSSM is the lightest neutralino:


Neutral gauginos

Direct detection in underground experiments

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.

- Very low energy : ER 10 keV

- Very small interaction rate : down to 10-5 c/kg/day

60 °



~30 km/s

~220 km/s



Dark matter (II)

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

100 kg NaI(Tl) detector mass (scintillation)

Seeannual modulation signal (hearthorbital motion)

Effect  5-7%

Isotropic halo and dispersoin velocity

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

Latest results astro-ph/0307403

(7 annual cycles)

58000 + 49800 = 107800 Kg.days

NaIAD 2002 (new 25 kg.yrs)

Dark matter (III)

Other experiments:

DAMA new

UK/Boulby : NaIAD (NaI)x-check for DAMA

UK/Boulby : ZEPLIN (Liq.Xe)

Stanford : CDMS (Ge e Si)

Frejus, France : EDELWEISS (Ge)


Comparison between different exps. extremely difficult

Different 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.

Summary of the cosmological section

The precision CMB studies opens a new era for Cosmology

We are close to a Standard Cosmology able to fit a large number

of observations

Activity 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.

New physics in b k s








New Physics in B   Ks ?

CP violation in the b sector:

  • B  J/ Ks

dominated by a tree-level amplitude

Belle (2003) 140 fb-1:

sin(2b) =0.733±0.057±0.028


sin(2b) =0.741±0.067±0.033

BaBar (2002) 81 fb-1:

Belle 2003: sin2beff = -0.96 ±0.50

Belle result 3.5σ off respect to SM

BaBar 2003: sin2beff (φ KS) = +0.45±0.43±0.07

Closer to SM respect to previous results

Hint of new physics in B   K ?

(NP effects might be large in loop induced processes)

2.1 s between BaBar and Belle:

more data absolutely needed to clarifythe situation

Global EW fit

NEW: MW(Aleph) lower, small shifts

in heavy flavors, atomic PV close to SM

new Mt D0 Run I and CDF Run II

not included


MH=96 GeV, MH<219 GeV at 95%CL

χ2/dof=25.4/15 4.5% prob

without NuTeV

MH=91 GeV, MH<202 GeV at 95%CL

χ2/dof=16.8/14 26.5% prob


except for NuTeV

The NuTeV result (I)

NuTeV at FERMILAB measures NC/CC cross sections in n DIS


NuTeV main new feature is having both n and n beams

Independent measure of sin2q using n/nNC/CC cross sections exploiting the PASCHOS-WOLFENSTEIN ratio

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

Corrections needed for:

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


The NuTeV result (II)

NuTeV works at LO in QCD and finds

sin2qw(NuTeV)=0.2276±0.0013stat ±0.0006syst ±0.0006th

-0.00003(Mt/GeV-175)+0.00032 lnMH/100GeV

Global EW fit:

sin2qw= 0.2229 ±0.0004

~ 2.8 s

Dalla misura separata di Rn, Rn

NuTeV suggests a smaller left-handed coupling

(III) NuTeV result O(1%) effect

possible SM explanations related to hadronic structure

Strange asymmetry

Isospin violation

A positive s- reduces the anomaly

Naturally of O(1%), ds2W 0.002

Different models give this order of magnitude, ds2W<0

Sather,Rodionov et al,Londergan&Thomas

Discrepancy reduced ~ 30%

New MRST fit confirms such estimation but very large uncertainties

NuTeV finds much smaller effect

mH = 500 GeV

NuTeV (IV) Strange Asymmetry

Recall:positive s- reduces the NuTeV anomaly

  • NuTeV: Dimuons (charm production)

  • s-=-0.0027±0.0013(low x) BUT NuTeV fit to s-

- relies on inconsistent parameterization (total strangeness S 0)

- does not fit s- in the context of global fit

  • 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:

Fewissues still open: large sea uncertainties and shift from s-could reduce discrepancy below 2σ

Given present understanding of hadron structure,

RPW is no good place for high precision physics

Asymmetries at the Z pole (I)

Problem: ~3σ discrepancybetween LR asymmetry of SLD and FB b asymmetry of LEP: in SM they measure the same quantity, sin2θeff

New AFB(b) preliminaries from OPAL and DELPHI

LEP: Zff



SLD: Z with beam pol.

Asymmetries (II)

The Chanowitz argument

2 possibilities, both involving new physics:

-AFB(b) points to new physics

-it’s a fluctuation or due to unknown syst.

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

without AFB(b) , the MH fit is very good

MH=42 GeV, MH<120 GeV at 95%CL

but in conflict with direct lower bound MH>114.4 GeV

In case, it ispossible to find NP that mimics a light Higgs.

For example SUSY can do thatwith light sleptons, tanβ>4

Altarelli et al

Conclusion is sensitive to top mass

improvement precision of Mtop is the priority Tevatron II

(g-2)m news (I)

Excellent place for new physics unexplored loop effects ~ m2µ/Λ2

but needs chiral enhancement

Supersymmetry is natural candidate at moderate/large tanβ

No experimental news: BNL g-2 experiment latest result from 2000 m+data

released 2002 :

soon result of 2001 m-data

expected 30% error reductions

Some theory developments:

4loop big, never checked!




Revised CMD-2

LxL change

of sign

(g-2)m news (II)

Incomplete compilation of theory predictions


Davier et al,

Hagiwara et al

Largest theoretical uncertainties from

Vacuum polarization integrals involve vector spectral functions

which can be experimentally determined from two sources:

- e+e- annihilation cross section (CMD-2)

- Hadronic tau decays (ALEPH, CLEO, OPAL)

Tau data

e+e- data

Final CMD-2 π π data (2002) 0.6% syst error!

CMD-2 have recently reanalyzed their data

Good agreement between Aleph, CLEO, Opal τ data

Davier at al (DEHZ)


Hagiwara et al (HMNT) NEW result:


~ 2-2.5σ

depending on which e+e- analysis

Agreement with exp. results

(g-2)m news (III)

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

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

- interesting NEW results from KLOE (e+e-  ppin the region0.37 < sπ<0.93 GeV)


- to be compared with the NEW CMD-2 (same s range)

δaμ(had)=378.6±2.6stat±2.2syst&th(it was 368.1)

Discrepancy with t data confirmed by KLOE

Further understanding needed

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











CVC + isospin symmetry

Corrections by Cirigliano et al 02

SM status summary

SM works fine

Despite the severe tests performed in the attempt to discover some sign of new physics

no 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.


Non accelerator physics

  • WMAP: towards a high-precision cosmology

  • Dark matter: DAMA result

  • News on solar n oscillations

  • News from CP violation in the b-sector

  • EW tests: possible disagreements with SM expectations

    • - NuTeV result

    • - sin2qW from forward-backward/left-right asymmetries

    • (g-2)m

  • Single top production: example of complementarity between different colliders

Gruppo I physics

Fcnc couplings involving the top quark
FCNC couplings involving the top quark ?

ZEUS Collab.,

PLB 559, 153 (2003)

Anomalous couplings between top, /Z and u/c may arise in SMextensions

  • single top production @ LEP & HERA

  • t  u/c + /Z @ Tevatron

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

  • not excluded by LEP & Run I data

  • ZEUS vs H1 : too few events so far…

  •  looking forward to doubling L !

  • Sensitivity @Tevatron :

  • mainly via radiative top decays

  • u/c  t :  quite large but huge bckgd !


H1 Prelim., Contrib. Paper #181

ZEUS Collab., PLB 559, 153 (2003)

Final DELPHI results, Contrib. Paper #53

L3, PLB 549 (2002) 290

Hera events with isolated lepton p t miss i
HERA events with isolated lepton + PT,miss (I)

e p   + jet + X

e p   + jet + X




Hera events with isolated lepton p t miss ii
HERA events with isolatedlepton+ PT,miss(II)

- No excess in H1 e- p data

- No excess in ZEUS data in e &  channels,  candidates

- Agreement in the had. channel (but large bckgd)

- W prod full NLO corrections included

(recently available)

H1 Collab., PLB 561, 241 (2003)

ZEUS Prelim

e & m

  had

130 pb-1

H1 e+ p data, 105 pb-1

e p  l+ jet + PT,miss

Main SM contribution :


Descrizione del fit

The simplest best fit model has 6 parameters and

The probability to exceed is 5%

Can combine data with external surveys as well.

Flat LCDM still fits

Baryon density Wbh2 0.024  0.001

Matter density Wmh2 0.14  0.02

Hubble constant h0.72  0.05

Amplitude A 0.9  0.1

Optical Depth t0.166 + 0.076 – 0.071

Spectral index ns0.99  0.04

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


Riess et al. 2001

Flat within errors

Improvement precision

respect to Boomerang

Using also results from SN

and galactic clusters

strong constraints on

WL and Wm

Verde et al 2002



Causal Seed model (Durrer et al. 2002)

Primordial Isocurvature i.c.

Preliminary studies

Data supports inflation

To some extent is possible to discriminate among different models

WMAP TE data in bins of Δl=10

Primordial Adiabatic i.c.


Beauty production at HERA

- Previously reported anomalies from HERA TEVATRON and LEP

  • btagged exploiting semileptonic

  • decay b  cm

  • Unfold from charm, uds using

  • d(Si) and Ptrel (m-jet)

  • Compare with NLO QCD directly in measured range

  • ZEUS results in quite good agreement with SM predictions

  • H1 photoproduction a bit above

- Larger statistics with HERA II data in the next future

b-tagging also will profit of the detectors upgrading in the vertex region









CPV news (I)

CP violation in SM due to a complex phase in CKM matrix

B-factories allow precise measurements in b-sector

and explore possiblebeyond SM sources of CPV

  • B  J/ Ks

dominated by a tree-level amplitude

- 2001 first signals for CPV outside of the kaon sector

Belle : sin(2b)=0.99±0.14±0.06

Babar : sin(2b) = 0.59±0.14±0.05

Updated results:

Belle (2003) 140 fb-1:


sin(2b) =0.733±0.057±0.028

BaBar (2002) 81 fb-1:

K (ek) and B (md,Vub , Vtd , sin (2)) sectors consistent with each other and SM

sin(2b) =0.741±0.067±0.033

Really going towards a precise measurement


DAMAexperiments at Gran Sasso

claims model independent evidence for

WIMPS in the galactic halo

Dark matter (II)

100 kg NaI detector mass (scintillation)

- First results (2002) based on

58000 kg-days exposure (4 years)

Mc ~ 52 GeV

sp ~ 7x10-6 pb

See annual modulation signal (hearth orbital motion)

  • Latest results astro-ph/0307403

  • (3 more annual cycles)

  • 58000 + 49800 = 107800 Kg-days

CPV news (II)

Search for New Physics in rare B-decays

Theoretically cleanest example:

In the SM

sin(2b)eff = sin(2b) (Bf KS )

BaBar 2003: sin2beff (φ KS) = +0.45±0.43±0.07

Closer to SM respect to previous results

Belle 2003: sin2beff = -0.96 ±0.50

Belle result 3.5σ off respect to SM

Current WA: sin(2b)=0.731±0.056

But 2.1 s between BaBar and Belle:

more data absolutely needed to clarifythe situation

E158 (SLAC) new results for PV in Moller scattering

Huge luminosity

High polarization (~80%)

  • suppressed at tree level

  • sensitive to sin2q

  • sensitive to new physics

  • complementary to collider exps.

Results in agreement with SM

sin2qeff(Q2=0.027 GeV2)=

0.2371  0.0025  0.0027

Soon results from Run II

Last run (III) is going very well

Final results next year

Hera multilepton events


H1 ( 115 pb-1)

ZEUS ( 130 pb-1)


2e, M > 100 GeV

3 / 0.30  0.04

2 / 0.77  0.08

3e, M > 100 GeV

3 / 0.23  0.04

0 / 0.37  0.04

HERA multilepton events

Search for events with several leptons in final state

Mainly produced via  collisions

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




observed / expected

(different angular ranges in H1 / ZEUS analyses)

Solar nnews





Assuming CPT only LMA solution compatible with deficit observed by KamLAND

Best fit (thres. 2.6 MeV):


Dm2=6.9 10-5 eV2

Solar neutrinos not a problem anymore:


  • SNO, (April 2002)

106 cm-2 s-1





  • FSNO=5.09

  • KamLAND (December 2002)

  • observed evidence for reactor neutrino disappearence at ~ 180 Km distance



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

Summary onn

MNSP matrix

Atmospheric, K2K


Accelerator, reactor

q13 not measured yet

Solar, KamLAND


  • n 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 n masses and mixing.

  • the old solar n problem, which tormented us since 60’, has been finally understood

  • In 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 n do oscillate.