Towards the trans-GZK area ray (from

AGASA, AUGER, HIRES TO JEM -

EUSO) J. N. Capdevielle, APC, University Paris Diderotcapdev@apc.univ-paris7.fr

OutlineOutline Towards Gamma ray Astronomy at UHE Towards Gamma ray Astronomy at UHE

from the skyfrom the sky Energy overestimation in AGASA Energy overestimation in AGASA

(treatment of inclined showers)(treatment of inclined showers) Difficulties in AUGER for Tmax and Difficulties in AUGER for Tmax and

attenuation length measurementsattenuation length measurements convergence to GZK and unified convergence to GZK and unified

tendancytendancy The JEM-EUSO experimentThe JEM-EUSO experiment

Xmax (g/cm2) and Nmax Xmax (g/cm2) and Nmax for p, Fe initiated showersfor p, Fe initiated showers

Geminated CascadesGeminated Cascades From From Centaurus (4 Centaurus (4

l.y.)l.y.) pair of pair of  ’s (10 ’s (1019 19 eV) eV)

separated by separated by 700 700 kmkm

time delay time delay for a for a pair p-pair p-((as 1/ as 1/ LL

22 , , L L lorentz factor)lorentz factor)

a proton (or n) of a proton (or n) of 101020 20 eV is delayed by eV is delayed by 0.6µs0.6µs

From spiral From spiral arms(6000 l.y)arms(6000 l.y)

pair of pair of  ’s lost ! ’s lost ! Time delay Time delay for a for a

pair p(or n)-pair p(or n)- ~ ~1ms1ms still interesting in still interesting in

the case of sourcesthe case of sources analysis analysis

possible in JEM-possible in JEM-EUSO up to 100 l.y.EUSO up to 100 l.y.

Extrapolation des modèles Extrapolation des modèles d’interactions hadroniquesd’interactions hadroniques

Première interaction importante donne les caractéristiques générales

de la gerbe (Nmax, Xmax et profil latéral)

Modèles théoriques sont ajustés sur les données expérimentales

Or pas de données au-delà de 1,8 TeV

dans le centre de masse (collisions pp) extrapolation

Distribution de pseudo-rapidité

Distribution de pseudo-rapidité

Pythia 6.122 APythia 6.122 modele 4

Pythia 5.724 AtlasPHOJET 1.11sajet

Herwig 5.9Isajet 7.32

Incertitudes Incertitudes

Prédictions pour le LHCà 14 TeV dans le centre de masse

Multiplicité entre 70 (Isajet ) et 125 (Pythia 6.122A)

• Combien de particules ?• Quelle énergie emportée par la particule leader

Violation du scaling de KNO (1000 collisions) 1020 eV

String Model and di-quark breaking

Valence quark

Valence diquark

2

Slope Regge :

/fmGeV 12

1Tension

Tp

L

qq21qq

3q

The pair is created when thedistance L exceeds a threshold value.

Above a threshold energy, the di-quarkis broken excluding recombinationof the leading cluster.

qq

Very large tension for the diquark partners ?Very large tension for the diquark partners ?

1q

3q

2q

Maximal tensionwhen the 3

valence quarksare at the largestdistance fromeach other, then

aligned.

Diquark separation

1 = 500 g/cm2 2 = 594 g/cm2

AGASA conversion 600 600

Treatment of inclined EAS data from surface arrays and GZK prediction

Jean Noël CAPDEVIELLE, F.COHEN, B.SZABELSKA, J.SZABELSKI

Measured: lateral distribution + direction (θ, φ)

Density (600m, θ) Density(600m, 0) Energy

That conversion is energy/size independent

Treatment of inclined EAS data from surface arrays and GZK prediction

Jean Noël CAPDEVIELLE, F.COHEN, B.SZABELSKA, J.SZABELSKI

Results of CORSIKAsimulations showcomplicatedand energy dependentform

example:

Conversion to ''vertical density''

Treatment of inclined EAS data from surface arrays and GZK prediction

Jean Noël CAPDEVIELLE, F.COHEN, B.SZABELSKA, J.SZABELSKI

How does the conversion to ''vertical density'' work ?

Treatment of inclined EAS data from surface arrays and GZK prediction

Jean Noël CAPDEVIELLE, F.COHEN, B.SZABELSKA, J.SZABELSKI

Cascade theory and CORSIKA simulations

results for the highest energies depend on interaction model,but suggest overestimation of energy at AGASA

Treatment of inclined EAS data from surface arrays and GZK prediction

Jean Noël CAPDEVIELLE, F.COHEN, B.SZABELSKA, J.SZABELSKI

From Bergman spectrum to AGASA spectrumusing AGASA conversion

Grey area: D.R.Bergman et al. (HiRes Collaboration) 29th ICRC, Pune, India, 2005

Red points: AGASA energy spectrum

histograms:MC generated spectrum following Bergman approximately recalculated spectrum using AGASA conversion

Treatment of inclined EAS data from surface arrays and GZK prediction

• The spectrum from surface array has to be corrected from the overestimation of the primary energy between 10°-35° in the last decade

• the amended spectrum of AGASA (ISVHECRI aug. 06) is progressing in this direction

• GZK after 4 decades is going to be confirmed by HIRES, AUGER, AGASA…

• The overestimation in AGASA data is mainly coming of the special properties of 3D Electromagnetic cascade near maximum, however this correction is small if the distance between maximum and AGASA level is more than 3 c.u. or for heavy composition

Signal dans AugerSignal dans Auger

Simulation densité de particulesDétecteurs Auger signal en Vertical Equivalent Muons (VEM)

Signal (r) = C1 e+e- (r) + C2 (r) VEM

Des simulations avec géant4 de la cuve d’Auger :C1 = 0,47

C2 = 0,9 – 1

Trans GZK AREATrans GZK AREA New scales New scales Adequate Adequate

Advanced Advanced TechnologiesTechnologies

Milesbornes to Milesbornes to Quantum GravityQuantum Gravity

earliest earliest approaches, EUSO approaches, EUSO and JEM-EUSOand JEM-EUSO

EUSO ~ 1000 x AGASA ~ 30 x AugerEUSO (Instantaneous) ~ 5000 x AGASA 　　　　　　　　　　　　　　　　　　　~ 150 x Auger

AGASA

JEM-EUSO tilt-mode

JEM-EUSO FoVJEM-EUSO FoV

by Boris Khrenov 2006

Progress of the study of EECR expected in the near future:

4×105JEM-EUSO(nadir)

JEM-EUSO　 (tilt)

Conclusions Conclusions

New chances for Gamma ray Astronomy at UHE from ISS with JEM-EUSO

New results of LHC updating the simulation

GZK behaviour confirmed but some ambiguities on composition remain

Xmax different from Xmax via fluorescence ?

Change in p-Air interaction above 3 EeV?

New Astrophysics with heavy component at UHE?

Crucial period for JEM-EUSO entering in the trans GZK area