Since 2004 we have collected a 1M cosmic-ray events, about 80 had energies exceeding 40 EeV, the energy at which the GZK flux suppression takes place. We found a strong association between the cosmic-ray directions and nearby AGN. 2007 data collected by the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of the cosmic rays with the highest-energies with 99% confidence level. The observed correlation demonstrates the extra-galactic origin of the highest-energy cosmic rays.
COBISS.SI-ID: 775419
The energy spectrum of cosmic rays above 2.5x10^18 eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index of the particle flux at energies between 4x10^18 and 4x10^19 eV is 2.69, steepening to 4.2 for 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.
COBISS.SI-ID: 926459
An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies greater than 10 EeV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays.
COBISS.SI-ID: 871931
Observation of a difference between direct charge-parity (CP) asymmetries for charged and neutral B meson decays into a kaon and a pion is reported. Although it is susceptible to strong interaction effects, this difference could be an indication of a new source of CP violation that is needed to explain the matter-dominated Universe. Experimental results are still consistent with the mechanism proposed by Kobayashi and Maskawa, which has a unique source of CP violation that is known to be too small to explain the elimination of antimatter.
COBISS.SI-ID: 21553703
This paper presents the first measurement of time asymmetries in the decays of pair-produced neutral B mesons into pairs of charged pions with different CP eigenstates as the original B. The measurements were done by the Belle spectrometer at asymmetric electron-positron collider KEK-B. We showed that these decays also manifest the direct violation of CP symmetry.
COBISS.SI-ID: 18417191