2006/11/30 by A. M. Gago, Joel Jones-Pérez, J. Jones-Perez · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1103/physrevd.75.033004
published as Phys.Rev.D75:033004,2007 · 40 pages, 18 figures; added references, corrected typos, updated Eq (15c)
openalex publication_date 2007/02/12 · arxiv created 2007/03/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 sin22\ensuremathθ13 in order to accomplish the unambiguous determination of \ensuremathθ23 and \ensuremathδ. We have performed two different analysis. In the first, at a baseline of 3000 km, we simulate a measurement of the channels \ensuremathνe\ensuremath→\ensuremathν_\ensuremathμ, \ensuremathνe\ensuremath→\ensuremathν_\ensuremathτ, and \ensuremathν_\ensuremathμ\ensuremath→\ensuremathν_\ensuremathμ, 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 \ensuremathνe\ensuremath→\ensuremathν_\ensuremathμ channel at 7250 km, the so-called ``magic baseline.'' In both cases, we have studied the impact of varying the \ensuremathν_\ensuremathτ detector efficiency-mass product, (ϵ_\ensuremathν_\ensuremathτ\ifmmode×\else\texttimes\fiM_\ensuremathτ), at 3000 km, keeping unchanged the \ensuremathν_\ensuremathμ detector mass and its efficiency. At L=3000 km, we found the existence of degenerate zones, that correspond to values of \ensuremathθ13, 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 overcome, demonstrating the relevance of the ``magic baseline.'' From this scenario, the best limits of sin22\ensuremathθ13, reached at 3\ensuremathσ, for sin22\ensuremathθ23=0.95, 0.975, and 0.99 are: 0.008, 0.015, and 0.045, respectively, obtained at \ensuremathδ=0, and considering (ϵ_\ensuremathν_\ensuremathτ\ifmmode×\else\texttimes\fiM_\ensuremathτ)\ensuremath≈125, which is 5 times the initial efficiency-mass combination.