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Towards the trans-GZK area ray (from AGASA, AUGER, HIRES TO JEM -EUSO). J. N. Capdevielle , APC, University Paris Diderot capdev@apc.univ-paris7.fr. Outline. Towards Gamma ray Astronomy at UHE from the sky Energy overestimation in AGASA (treatment of inclined showers)
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Towards the trans-GZK area ray (from AGASA, AUGER, HIRES TO JEM -EUSO) J. N. Capdevielle, APC, University Paris Diderot capdev@apc.univ-paris7.fr
Outline • Towards Gamma ray Astronomy at UHE from the sky • Energy overestimation in AGASA (treatment of inclined showers) • Difficulties in AUGER for Tmax and attenuation length measurements • convergence to GZK and unified tendancy • The JEM-EUSO experiment
From a Centaurus (4 l.y.) pair of g ’s (1019 eV) separated by D~ 700 km time delay t for a pair p-g (t as 1/ gL2 , gL lorentz factor) a proton (or n) of 1020 eV is delayed by 0.6µs From spiral arms(6000 l.y) pair of g ’s lost ! Time delay t for a pair p(or n)-g ~1ms t still interesting in the case of sources D, t analysis possible in JEM-EUSO up to 100 l.y. Geminated Cascades
Extrapolation des modèles d’interactions hadroniques Distribution de pseudo-rapidité 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 Pythia 6.122 A Pythia 6.122 modele 4 Pythia 5.724 Atlas PHOJET 1.11sajet Herwig 5.9 Isajet 7.32 Incertitudes Prédictions pour le LHC à 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
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 AGASA conversion600 600: 1 = 500 g/cm2 2 = 594 g/cm2 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 Conversion to ''vertical density'' example: Results of CORSIKA simulations show complicated and energy dependent form
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 spectrum using AGASA conversion Red points: AGASA energy spectrum Grey area: D.R.Bergman et al. (HiRes Collaboration) 29th ICRC, Pune, India, 2005 • 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 Auger Simulation densité de particules Détecteurs 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 AREA • New scales • Adequate Advanced Technologies • Milesbornes to Quantum Gravity • earliest approaches, EUSO and JEM-EUSO
JEM-EUSO FoV JEM-EUSO tilt-mode EUSO ~ 1000 x AGASA ~ 30 x Auger EUSO (Instantaneous) ~ 5000 x AGASA ~ 150 x Auger AGASA
Progress of the study of EECR expected in the near future: JEM-EUSO (tilt) JEM-EUSO(nadir) 4×105 by Boris Khrenov 2006
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