472 research outputs found
Physics Reach with a Monochromatic Neutrino Beam from Electron Capture
Neutrino oscillation experiments from different sources have demonstrated
non-vanishing neutrino masses and flavour mixings. The next experiments have to
address the determination of the connecting mixing U(e3) and the existence of
the CP violating phase. Whereas U(e3) measures the strength of the oscillation
probability in appearance experiments, the CP phase acts as a phase-shift in
the interference pattern. Here we propose to separate these two parameters by
energy dependence, using the novel idea of a monochromatic neutrino beam
facility based on the acceleration of ions that decay fast through electron
capture. Fine tuning of the boosted neutrino energy allows precision
measurements able to open a window for the discovery of CP violation, even for
a mixing as small as 1 degree.Comment: 4 pages, 1 figure. Talk given at the International Europhysics
Conference on High Energy Physics, HEP-EPS 2005, Lisbon, Portugal, July
21-27, 200
Perspectives in Neutrino Physics: Monochromatic Neutrino Beams
In the last few years spectacular results have been achieved with the
demonstration of non vanishing neutrino masses and flavour mixing. The ultimate
goal is the understanding of the origin of these properties from new physics.
In this road, the last unknown mixing must be determined. If it is
proved to be non-zero, the possibility is open for Charge Conjugation-Parity
(CP) violation in the lepton sector. This will require precision experiments
with a very intense neutrino source. Here a novel method to create a
monochromatic neutrino beam, an old dream for neutrino physics, is proposed
based on the recent discovery of nuclei that decay fast through electron
capture. Such nuclei will generate a monochromatic directional neutrino beam
when decaying at high energy in a storage ring with long straight sections. We
also show that the capacity of such a facility to discover new physics is
impressive, so that fine tuning of the boosted neutrino energy allows precision
measurements of the oscillation parameters even for a mixing as
small as 1 degree. We can thus open a window to the discovery of CP violation
in neutrino oscillations.Comment: 15 pages, 7 figures. Contribution to the proceedings of GUSTAVOFEST -
Symposium in Honour of Gustavo C. Branco: CP Violation and the Flavour
Puzzle, Lisbon, Portugal, 19-20 July 200
Physics Potential of the SPL Super Beam
Performances of a neutrino beam generated by the CERN SPL proton driver are
computed considering a 440 kton water Cerenkov detector at 130 km from the
target. sensitivity down to and a
sensitivity comparable to a Neutrino Factory, for ,
are within the reach of such a project.Comment: Invited talk at the Nufact02 Workshop, Imperial College of Science,
Technology and Medicine, London, July 200
Neutrino Induced Charged Current 1 Production At Intermediate Energies
The charged current one pion production induced by from nucleons
and nuclei like C and O nuclei has been studied. The calculations
have been done for the incoherent and the coherent processes from nuclear
targets assuming the dominance model and take into account the effect
of Pauli blocking, Fermi motion of the nucleon and renormalization of
properties in a nuclear medium. The effect of final state interactions of pions
has been taken into account. The theoretical uncertainty in the total cross
sections due to various parameterizations of the weak transition form factors
used in literature has been studied. The numerical results for the total cross
sections are compared with the recent preliminary results from the MiniBooNE
collaboration on C and could be useful in analyzing future data from the
K2K collaboration.Comment: 10 pages, 6 figures, 1 tabl
Physics Potential of Very Intense Conventional Neutrino Beams
The physics potential of high intensity conventional beams is explored. We
consider a low energy super beam which could be produced by a proposed new
accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil
scintillator detectors are studied as possible candidates for a neutrino
oscillation experiment which could improve our current knowledge of the
atmospheric parameters and measure or severely constrain the parameter
connecting the atmospheric and solar realms. It is also shown that a very large
water detector could eventually observe leptonic CP violation. The reach of
such an experiment to the neutrino mixing parameters would lie in-between the
next generation of neutrino experiments (MINOS, OPERA, etc) and a future
neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice,
March, 200
Neutrino Factories and the "Magic" Baseline
We show that for a neutrino factory baseline of a
``clean'' measurement of becomes possible, which is
almost unaffected by parameter degeneracies. We call this baseline "magic"
baseline, because its length only depends on the matter density profile. For a
complete analysis, we demonstrate that the combination of the magic baseline
with a baseline of 3000 km is the ideal solution to perform equally well for
the , sign of , and CP violation
sensitivities. Especially, this combination can very successfully resolve
parameter degeneracies even below .Comment: Minor changes, final version to appear in PRD, 4 pages, 3 figures,
RevTe
Untangling CP Violation and the Mass Hierarchy in Long Baseline Experiments
In the overlap region, for the normal and inverted hierarchies, of the
neutrino-antineutrino bi-probability space for appearance,
we derive a simple identity between the solutions in the (, ) plane for the different hierarchies. The
parameter sets the scale of the
appearance probabilities at the atmospheric eV whereas controls the amount of CP
violation in the lepton sector. The identity between the solutions is that the
difference in the values of for the two hierarchies equals twice
the value of divided by the {\it critical} value
of . We apply this identity to the two proposed
long baseline experiments, T2K and NOA, and we show how it can be used to
provide a simple understanding of when and why fake solutions are excluded when
two or more experiments are combined. The identity demonstrates the true
complimentarity of T2K and NOA.Comment: 15 pages, Latex, 4 postscript figures. Submitted to New Journal of
Physics, ``Focus on Neutrino Physics'' issu
Unveiling Neutrino Mixing and Leptonic CP Violation
We review the present understanding of neutrino masses and mixings,
discussing what are the unknowns in the three family oscillation scenario.
Despite the anticipated success coming from the planned long baseline neutrino
experiments in unraveling the leptonic mixing sector, there are two important
unknowns which may remain obscure: the mixing angle and the
CP-phase . The measurement of these two parameters has led us to
consider the combination of superbeams and neutrino factories as the key to
unveil the neutrino oscillation picture.Comment: Invited brief review, 18 pages, 6 figure
The Physics Potential of Future Long Baseline Neutrino Oscillation Experiments
We discuss in detail different future long baseline neutrino oscillation
setups and we show the remarkable potential for very precise measurements of
mass splittings and mixing angles. Furthermore it will be possible to make
precise tests of coherent forward scattering and MSW effects, which allow to
determine the sign of . Finally strong limits or measurements of
leptonic CP violation will be possible, which is very interesting since it is
most likely connected to the baryon asymmetry of the universe.Comment: 32 pages, 15 figures, to appear in ``Neutrino Mass'', Springer Tracts
in Modern Physics, ed. by G. Altarelli and K. Winter, references adde
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