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Register a new userEvidence for Declination Dependence of Ultrahigh Energy Cosmic Ray Spectrum in the Northern Hemisphere
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R.U. Abbasi
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The energy of the ultrahigh energy spectral cutoff was measured, integrating over the northern hemisphere sky, by the Telescope Array (TA) collaboration, to be $10^{19.78 pm 0.06}$ eV, in agreement with the High Resolution Flys Eye (HiRes) experiment, whereas the Pierre Auger experiment, integrating over the southern hemisphere sky, measured the cutoff to be at 10$^{19.62 pm 0.02}$ eV. An 11% energy scale difference between the TA and Auger does not account for this difference. However, in comparing the spectra of the Telescope Array and Pierre Auger experiments in the band of declination common to both experiments ($-15.7^{circ} < delta < 24.8^{circ}$) we have found agreement in the energy of the spectral cutoff. While the Auger result is essentially unchanged, the TA cutoff energy has changed to $10^{19.59 pm 0.06}$ eV. In this paper we argue that this is an astrophysical effect.
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