From direct observations of the longitudinal development of ultra-high energy air showers performed with the Pierre Auger Observatory, upper limits of fraction of cosmic-ray photons. The results complement previous constraints on top–down models from array data and they reduce systematic uncertainties in the interpretation of shower data in terms of primary ?ux, nuclear composition and proton-air cross-section.
COBISS.SI-ID: 1144059
Data collected at the Pierre Auger Observatory are used to establish an upper limit on the diffuse ?ux of tau neutrinos in the cosmic radiation. Earth-skimming tau neutrinos may interact in the Earth’s crust and produce a lepton by means of charged-current interactions. The lepton may emerge from the Earth and decay in the atmosphere to produce a nearly horizontal shower. No neutrino candidates have been found. For neutrinos in the energy range 2x10^17 eV ( E ( 2x10^19 eV a 90% con?dence-level upper limit of E^2 dN/dE ( 9x10^8 GeV / cm^2 s sr. was obtained.
COBISS.SI-ID: 1160699
We studied B--)K(*) l+ l- decays (l=e,mu) based on a data sample of 657 million BB pairs collected with the Belle detector at the KEKB e+e- collider. We reported the differential branching fraction, isospin asymmetry, K* polarization, and the forward-backward asymmetry (AFB) as functions of q^2. The fitted AFB spectrum exceeds the Standard Model expectation by 2.7 standard deviations allowing for new physics.
COBISS.SI-ID: 23094055
Single photons detected by the DELPHI experiment at LEP2 in the years 1997-2000 are reanalysed to investigate the existence of a single extra dimension in a modified ADD scenario with slightly warped large extra dimensions. The data collected at centre-of-mass energies between 180 and 209 GeV for an integrated luminosity of ~650 pb^{-1} agree with the predictions of the Standard Model and allow a limit to be set on graviton emission in one large extra dimension. The limit obtained on the fundamental mass scale M_D is 1.69 TeV/c^2 at 95% CL, with an expected limit of 1.71 TeV/c^2.
COBISS.SI-ID: 1108731
We have developed an accurate simulation model of the large 9 inch photomultiplier tubes (PMT) used in water-Cherenkov detectors of cosmic-ray induced extensive air-showers. This work was carried out as part of the development of the \Offline simulation software for the Pierre Auger Observatory surface array, but our findings may be relevant also for other astrophysics experiments that employ similar large PMTs.
COBISS.SI-ID: 1324539