Résumé / Abstract Seminaire_IAP
« Surprises at Ultra High Energies: the cosmic ray neutrino connection »

Angela Olinto
Univ. Chicago (Chicago, Illinois, Etats-Unis d'Amérique)

The Pierre Auger Observatory has surpassed any previous ultrahigh energy observatory by an order of magnitude (or more?). This increase in sensitivity has provided a number of new results, both expected and unexpected. The expected spectral feature at the highest energies was clearly observed, but is it the predicted GZK effect? The hints of anisotropy in the sky distribution above 60 EeV seem to confirm that expectation and the possibility of detecting the first source of ultrahigh energy cosmic rays may be around the corner. However the studies of shower properties at the highest energies seem to point in a different direction.

Are the highest energy cosmic rays heavier nuclei or do proton interaction properties change significantly at energies past 100 TeV center of mass? The answer to this question can lead to orders of magnitude changes in the expected cosmogenic neutrino. Conversely, the observation of neutrinos at ultrahigh energies combined with continuing observations of UHECRs will unable a systematic study of particle interactions at energies well beyond current terrestrial accelerators.
vendredi 22 avril 2011 - 11:00
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage