826 research outputs found
Large-angle scattering of multi-GeV muons on thin Lead targets
The probability of large-angle scattering for multi-GeV muons in thin () lead targets is studied. The new estimates presented here are
based both on simulation programs (GEANT4 libraries) and theoretical
calculations. In order to validate the results provided by simulation, a
comparison is drawn with experimental data from the literature. This study is
particularly relevant when applied to muons originating from
interactions of CNGS beam neutrinos. In that circumstance the process under
study represents the main background for the search in
the channel for the OPERA experiment at LNGS. Finally, we also
investigate, in the CNGS context, possible contributions from the muon
photo-nuclear process which might in principle also produce a large-angle muon
scattering signature in the detector
Overview on neutrino oscillations
I will discuss recent achievements in the study of neutrino oscillations obtained with the T2K, OPERA and ICARUS long-baseline neutrino experiments
A new design for the CERN-Fr\'ejus neutrino Super Beam
We present an optimization of the hadron focusing system for a low-energy
high-intensity conventional neutrino beam (Super-Beam) proposed on the basis of
the HP-SPL at CERN with a beam power of 4 MW and an energy of 4.5 GeV. The far
detector would be a 440 kton Water Cherenkov detector (MEMPHYS) located at a
baseline of 130 km in the Fr\'ejus site. The neutrino fluxes simulation relies
on a new GEANT4 based simulation coupled with an optimization algorithm based
on the maximization of the sensitivity limit on the mixing angle.
A new configuration adopting a multiple horn system with solid targets is
proposed which improves the sensitivity to and the CP violating
phase .Comment: 11 pages, 18 figures, 2 table
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
A novel technique for the measurement of the electron neutrino cross section
Absolute neutrino cross section measurements are presently limited by
uncertainties on fluxes. In this paper, we propose a technique that is
based on the reconstruction of large angle positrons in the decay tunnel to
identify three-body semileptonic decays. This
tagging facility operated in positron counting mode ("event count mode") can be
employed to determine the absolute flux at the neutrino detector with
precision. Facilities operated in "event by event tag mode"
i.e. tagged neutrino beams that exploit the time coincidence of the positron at
source and the interaction at the detector, are also discussed.Comment: 23 pages, 7 figures. Version to appear in EPJ
New results from T2K
The T2K experiment is a 295-km long-baseline neutrino experiment in Japan employing an off-axis muon neutrino beam with a ~ 0.6 GeV peak energy. The beam, produced from 30-GeV protons at the J-PARC complex on the Pacific coast, is directed to the Super-Kamiokande detector. T2K released the first long-baseline measurement of a nonzero value for the θ 13 mixing parameter through the observation of electron neutrino appearance ( v µ → v e ) and produced the most precise measurement of θ 23 through the observation of muon neutrino disappearance ( v µ → v µ ). T2K data, in combination with reactor experiments, also excludes at 90% C.L. a significant region of the Dirac CP phase: δ CP δ CP > -0.49(-0.98) for the normal (inverted) hierarchy. A full joint appearance and disappearance fit including both neutrino (7×10 20 protons on target, PoT) and anti-neutrino (4 × 10 20 PoT) data and, for the first time, a constraint from water target data in the near detector, is presented yielding improved sensitivity on δ CP and improved precision on sin 2 2 θ 23 and the atmospheric mass splitting
EURONU WP6 2009 yearly report: Update of the physics potential of Nufact, superbeams and betabeams
Many studies in the last ten years have shown that we can measure the unknown
angle theta13, discover leptonic CP violation and determine the neutrino
hierarchy in more precise neutrino oscillation experiments, searching for the
subleading channel nue -> numu in the atmospheric range. In this first report
of WP6 activities the following new results are reviewed: (1) Re-evaluation of
the physics reach of the upcoming generation of experiments to measure theta13
and delta; (2) New tools to explore a larger parameter space as needed beyond
the standard scenario; (3) Neutrino Factory: (a) evaluation of the physics
reach of a Nufact regards sterile neutrinos; (b) evaluation of the physics
reach of a Nufact as regards non-standard interactions; (c) evaluation of the
physics reach of a Nufact as regards violation of unitarity; (d) critical
assessment on long baseline tau-detection at Nufact; (e) new physics searches
at a near detector in a Nufact; (4) Beta-beams: (a) choice of ions and location
for a gamma = 100 CERN-based beta-beam; (b) re-evaluation of atmospheric
neutrino background for the gamma = 100 beta-beam scenario; (c) study of a two
baseline beta-beam; (d) measuring absolute neutrino mass with beta-beams; (e)
progress on monochromatic beta-beams; (5) Update of the physics potential of
the SPL super-beam. Eventually, we present an updated comparison of the
sensitivity to theta13, delta and the neutrino mass hierarchy of several of the
different proposed facilities.Comment: 2009 Yearly report of the Working Package 6 (Physics) of the EUROnu
FP7 EU project. 55 pages, 21 figures
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