occasional meanderings in physics' brave new world

Name:
Location: New Zealand

Marni D. Sheppeard

## Sunday, June 01, 2008

### Neutrino08 Day 6b

E. Roulet reported from the Pierre Auger Cosmic Ray Observatory in Argentina. This consists of 1600 detectors spread over 3000 $\textrm{km}^{2}$ along with 24 telescopes looking at the sky over the region. Pierre Auger recently confirmed the infamous GZK cutoff (more on this later) associated to proton energies greater than $6 \times 10^{19}$ eV. Rather, although high energy events were observed, the flux falls off by about a half with more than $6 \sigma$. High energy events are extragalactic. For 2006-2007 data, 8 strong correlations between events and nearby AGN were found, as compared to 3 expected. Centaurus A (the closest AGN) corresponds to 2 events located within 3 degrees. No candidates for diffuse neutrino flux were observed. Construction of Pierre Auger is almost completed.