2,604 research outputs found
A parameterisation of single and multiple muons in the deep water or ice
Atmospheric muons play an important role in underwater/ice neutrino
detectors. In this paper, a parameterisation of the flux of single and multiple
muon events, their lateral distribution and of their energy spectrum is
presented. The kinematics parameters were modelled starting from a full Monte
Carlo simulation of the interaction of primary cosmic rays with atmospheric
nuclei; secondary muons reaching the sea level were propagated in the deep
water. The parametric formulas are valid for a vertical depth of 1.5-5 km w.e.
and up to 85 deg for the zenith angle, and can be used as input for a fast
simulation of atmospheric muons in underwater/ice detectors.Comment: 25 pages, 8 figure
CP violation and mass hierarchy at medium baselines in the large theta(13) era
The large value of theta(13) recently measured by rector and accelerator
experiments opens unprecedented opportunities for precision oscillation
physics. In this paper, we reconsider the physics reach of medium baseline
superbeams. For theta(13) ~ 9 degree we show that facilities at medium
baselines -- i.e. L ~ O(1000 km) -- remain optimal for the study of CP
violation in the leptonic sector, although their ultimate precision strongly
depends on experimental systematics. This is demonstrated in particular for
facilities of practical interest in Europe: a CERN to Gran Sasso and CERN to
Phyasalmi nu_mu beam based on the present SPS and on new high power 50 GeV
proton driver. Due to the large value of theta(13), spectral information can be
employed at medium baselines to resolve the sign ambiguity and determine the
neutrino mass hierarchy. However, longer baselines, where matter effects
dominate the nu_mu->nu_e transition, can achieve much stronger sensitivity to
sign(Delta m^2) even at moderate exposures.Comment: 14 pages, 14 figures, version to appear in EPJ
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