Telescope Array Experiment:Status and ProspectsPierre SokolskyUniversity of Utah

Cosmic Ray Spectrum

5 Observation of the GZK Suppression (mono)

HiRes/Auger spectra comparisonAuger confirms all spectral features of HiRes spectrum

UHECR Status and IssuesGZK cutoff exists HiRes and PAO observe at 5-6 sigma levelAnisotropy ( sources ) remain unclear- 2-3 sigma correlation in South with AGNs (PAO), no correlations in North (HiRes).Composition light (proton) favored by HiRes. Light-heavy-light(?) favored by PAO>>> A lot more work is required>>> Unravelling galactic/extragalactic transition

Motivation for TAAGASA and HiRes give conflicting results on GZK. Why?Increase SD by 10 x. Coincident event observation with FD. Keep AGASA and HiRes energy scales Hybrid events > calibrate SDSD 10 x higher statistics than HiRes

Motivation for TALESources of cosmic rays above knee (1015 eV) are unknown.What is the Emax of the galactic accelerator?Connect energy scale established by GZK to all the other structures in the cr spectrum ( ankle, second knee etc.)Study the composition change from galactic to extragalactic cosmic rays.

TALE Proposal under consideration by PASAG

Thank You!