4,463 research outputs found
Revising the Solution of the Neutrino Oscillation Parameter Degeneracies at Neutrino Factories
In the context of neutrino factories, we review the solution of the
degeneracies in the neutrino oscillation parameters. In particular, we have set
limits to in order to accomplish the unambiguous
determination of and . We have performed two different
analysis. In the first, at a baseline of 3000 km, we simulate a measurement of
the channels , and
, combined with their respective conjugate ones,
with a muon energy of 50 GeV and a running time of five years. In the second,
we merge the simulated data obtained at L=3000 km with the measurement of
channel at 7250 km, the so called 'magic baseline'. In both
cases, we have studied the impact of varying the detector
efficiency-mass product, , at 3000 km,
keeping unchanged the detector mass and its efficiency. At L=3000 km,
we found the existance of degenerate zones, that corresponds to values of
, which are equal or almost equal to the true ones. These zones
are extremely difficult to discard, even when we increase the number of events.
However, in the second scenario, this difficulty is overcomed, demostrating the
relevance of the 'magic baseline'. From this scenario, the best limits of
, reached at , for ,
0.975 and 0.99 are: 0.008, 0.015 and 0.045, respectively, obtained at
, and considering ,
which is five times the initial efficiency-mass combination.Comment: 40 pages, 18 figures; added references, corrected typos, updated Eq
(15c
Solid flow drives surface nanopatterning by ion-beam irradiation
Ion Beam Sputtering (IBS) is known to produce surface nanopatterns over
macroscopic areas on a wide range of materials. However, in spite of the
technological potential of this route to nanostructuring, the physical process
by which these surfaces self-organize remains poorly under- stood. We have
performed detailed experiments of IBS on Si substrates that validate dynamical
and morphological predictions from a hydrodynamic description of the
phenomenon. Our results elucidate flow of a nanoscopically thin and highly
viscous surface layer, driven by the stress created by the ion-beam, as a
description of the system. This type of slow relaxation is akin to flow of
macroscopic solids like glaciers or lead pipes, that is driven by defect
dynamics.Comment: 12 pages, 4 figure
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