DOI: 10.1140/epjc/s2002-01064-7
Impact of two mass scale oscillations on the analysis of atmospheric and reactor neutrino data
M.C. Gonzalez-Garcia1, 2, 3 and M. Maltoni21 Theory Division, CERN, 1211 Geneva 23, Switzerland
2 Instituto de Física Corpuscular, Universitat de València - C.S.I.C., Edificio Institutos de Paterna, Apt. 22085, 46071 Valencia, Spain
3 C.N. Yang Institute for Theoretical Physics, State University of New York at Stony Brook, NY, USA
(Received: 31 May 2002 / Revised version: 10 July 2002 / Published online: 31 October 2002 )
Abstract
We study the stability of the results of
the three-neutrino oscillation analysis of
atmospheric and reactor neutrino data under departures of the
one dominant mass scale approximation. In order to do so
we perform the analysis of atmospheric and reactor neutrino data
in terms of three-neutrino oscillations where the effect of both
mass differences is explicitly considered. We study the allowed
parameter space resulting from this analysis as a function of the
mass splitting hierarchy parameter
which parameterizes the departure from the one dominant
mass scale approximation. We consider schemes with both direct and
inverted mass ordering. Our results show that in the analysis
of the atmospheric data the derived range of the largest mass splitting,
, is stable, while the allowed
ranges of mixing angles
and
are wider than those obtained in
the one dominant mass scale approximation. Inclusion of the CHOOZ
reactor data in the analysis results in the reduction of the
parameter space in particular for the mixing angles.
As a
consequence the final allowed ranges of the
parameters from the combined
analysis are only slightly broader than when obtained in the
one dominant mass scale approximation.
© Società Italiana di Fisica, Springer-Verlag 2003
