We perform a new, detailed calculation of the flux and energy spectrum of Earth-emerging leptons generated from the interactions of tau neutrinos and antineutrinos in the Earth. A layered model of the Earth is used to describe the variable density profile of the Earth. Different assumptions regarding the neutrino charged- and neutral-current cross sections as well as the -lepton energy loss models are used to quantify their contributions to the systematic uncertainty.
View Article and Find Full Text PDFThis paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, [Formula: see text] and to search for weakly-interacting sub-GeV dark matter candidates.
View Article and Find Full Text PDFA next-to-leading-order (NLO) calculation of neutrino cross sections, including power-suppressed mass terms, is used to evaluate the Paschos-Wolfenstein ratio, in order to better assess the validity and significance of the NuTeV anomaly. We study the shift of sin2thetaW obtained in calculations with parton distribution function sets that allow s(x) not = s(x), enabled by recent neutrino dimuon data from CCFR and NuTeV. The extracted value of sin2thetaW is closely correlated with the strangeness asymmetry.
View Article and Find Full Text PDF