The energy spectrum of cosmic rays above 2.5 x 10^18 eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional to E^(-gamma), at energies between 4 x 10^18 eV and 4 x 10^19 eV is 2.69 +- 0.02(stat) +- 0.06(syst), steepening to 4.2 +- 0.4(stat) +- 0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz’min.

The energy spectrum of cosmic rays above 2.5 x 10(18) eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional to E(-gamma), at energies between 4 x 10(18) eV and 4 x 10(19) eV is 2.69 +/- 0.02(stat) +/- 0.06(syst), steepening to 4.2 +/- 0.4(stat) +/- 0: 06 (syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Observation of the suppression of the flux of cosmic rays above 4 x 10^19 eV

Blasi P;De Mitri I.;
2008

Abstract

The energy spectrum of cosmic rays above 2.5 x 10^18 eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional to E^(-gamma), at energies between 4 x 10^18 eV and 4 x 10^19 eV is 2.69 +- 0.02(stat) +- 0.06(syst), steepening to 4.2 +- 0.4(stat) +- 0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz’min.
The energy spectrum of cosmic rays above 2.5 x 10(18) eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional to E(-gamma), at energies between 4 x 10(18) eV and 4 x 10(19) eV is 2.69 +/- 0.02(stat) +/- 0.06(syst), steepening to 4.2 +/- 0.4(stat) +/- 0: 06 (syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.
Raggi cosmici; Energia ultra alta; Sciami atmosferici estesi; Osservatorio Pierre Auger
File in questo prodotto:
File Dimensione Formato  
2008_PhysRevLett_101_Abraham.pdf

non disponibili

Tipologia: Versione Editoriale (PDF)
Licenza: Non pubblico
Dimensione 263.07 kB
Formato Adobe PDF
263.07 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/20.500.12571/3114
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 641
  • ???jsp.display-item.citation.isi??? 484
social impact