5 research outputs found
A new fit to solar neutrino data in models with large extra dimensions
String inspired models with millimeter scale extra dimensions provide a
natural way to understand an ultralight sterile neutrino needed for a
simultaneous explanation of the solar, atmospheric and LSND neutrino
oscillation results. The sterile neutrino is the bulk neutrino ()
postulated to exist in these models, and it becomes ultralight in theories that
prevent the appearance of its direct mass terms. Its Kaluza-Klein (KK) states
then add new oscillation channels for the electron neutrino emitted from the
solar core. We show that successive MSW transitions of solar to the
lower lying KK modes of in conjunction with vacuum oscillations between
the and the zero mode of provide a new way to fit the solar
neutrino data. Using just the average rates from the three types of solar
experiments, we predict the Super-Kamiokande spectrum with 73\% probability,
but dips characteristic of the 0.06 mm extra dimension should be seen in the
SNO spectrum. We discuss both intermediate and low string scale models where
the desired phenomenology can emerge naturally.Comment: 20 pages, contains updated SuperK results and reference
High scale mixing unification and large neutrino mixing angles
Starting with the hypothesis that quark and lepton mixings are identical at
or near the GUT scale, we show that the large solar and atmospheric neutrino
mixing angles together with the small reactor angle can be understood
purely as a result of renormalization group evolution. The only requirements
are that the three neutrinos must be quasi degenerate in mass and have same CP
parity. It predicts that the common Majorana mass for the neutrinos must be
larger than 0.1 eV making the idea testable in the currently planned or ongoing
experiments searching for neutrinoless-double-beta decay.Comment: 10 pages, eight figure, two tables; new material added; results
remain unchange