Giorgio Giacomelli

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Many galactic and extragalactic astrophysical sources are currently considered promising candidates as high-energy neutrino emitters. Astrophysical neutrinos can be detected as upward-going muons produced in charged-current interactions with the medium surrounding the detector. The expected neutrino fluxes from various models start to dominate on the(More)
Cross-sections and angular distributions for hadronic and lepton pair final states in e+e− collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The results are used to measure the energy dependence of the electromagnetic coupling constant αem, and(More)
The final analysis of atmospheric neutrino events collected with theMACROdetector is presented. Three different classes of events, generated by neutrinos in different energy ranges, are studied looking at rates, angular distributions and estimated energies. The results are consistent for all the subsamples and indicate a flux deficit that depends on energy(More)
The ANTARES collaboration is building a deep sea neutrino telescope in the Mediterranean Sea. This detector will cover a sensitive area of typically 0:1 km and will be equipped with about 1000 optical modules. Each of these optical modules consists of a large area photomultiplier and its associated electronics housed in a pressure resistant glass sphere.(More)
Using data collected by the MACRO experiment from 1989 to the end of its operations in 2000, we have studied in the underground muon flux the shadowing effects due to both the Moon and the Sun. We have observed the shadow cast by the Moon at its apparent position with a significance of 6.5 σ. The Moon shadowing effect has been used to verify the pointing(More)
ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced,(More)
We have searched for unstable neutral and charged heavy leptons, N and L ± , and for excited states of neutral and charged leptons, ν * , e * , µ * and τ * , in e + e − collisions at centre-of-mass energies of 170 and 172 GeV using the OPAL detector at LEP. No evidence for their existence was found. From the analysis of charged-current decays of(More)
QCD coherence effects are studied based on measurements of correlations of particles with either restricted transverse momenta, p T < p cut T , where p T is defined with respect to the thrust axis, or restricted absolute momenta, p ≡ |p| < p cut , using about four million hadronic Z decays recorded at LEP with the OPAL detector. The correlations are(More)