4,709 research outputs found
Hierarchical majorana neutrinos from democratic mass matrices
In this paper, we obtain the light neutrino masses and mixings consistent
with the experiments, in the democratic texture approach. The essential ansatz
is that are assumed to transform as "right-handed fields" under the symmetry. The symmetry breaking terms
are assumed to be diagonal and hierarchical. This setup only allows the normal
hierarchy of the neutrino mass, and excludes both of inverted hierarchical and
degenerated neutrinos.
Although the neutrino sector has nine free parameters, several predictions
are obtained at the leading order. When we neglect the smallest parameters
and , all components of the mixing matrix are expressed by the masses of light neutrinos and charged leptons. From
the consistency between predicted and observed , we obtain the
lightest neutrino masses = (1.1 1.4) meV, and the effective mass
for the double beta decay \vev{m_{ee}} \simeq 4.5 meV.Comment: 14 pages, 1 table, substantially revised versio
Flavor structure from misalignment of inner products in noncommutative geometry
In this letter, we consider an idea that induces flavor structure from inner
products in noncommutative geometry. Assuming proper components of vectors
in enlarged representation space for fermions, we can induce the
waterfall texture for Yukawa matrices retaining gauge interactions are
universal. The hierarchy of the Yukawa interactions is a consequence of
"misalignment" between the vectors and .Comment: 6pages, 1 table, the final version to appear in JHE
Effect of lift force on the aerodynamics of dust grains in the protoplanetary disk
We newly introduce lift force into the aerodynamics of dust grains in the
protoplanetary disk. Although many authors have so far investigated the effects
of the drag force, gravitational force and electric force on the dust grains,
the lift force has never been considered as a force exerted on the dust grains
in the gas disk. If the grains are spinning and moving in the fluid, then the
lift force is exerted on them. We show in this paper that the dust grains can
be continuously spinning due to the frequent collisions so that the lift force
continues to be exerted on them, which is valid in a certain parameter space
where the grain size is larger than ~ 1 m and where the distance from the
central star is larger than 1 AU for the minimum mass solar nebula. In
addition, we estimate the effects of the force on the grain motion and obtain
the result that the mean relative velocity between the grains due to the lift
force is comparable to the gas velocity in the Kepler rotational frame when the
Stokes number and lift-drag ratio are both ~ 1. This estimation is performed
under the assumptions of the steady state and the isotropic spin angular
momentum. We also estimate the mean relative velocity when the grains keep
spinning and conclude that the lift force marginally affects the mean relative
velocity in the minimum mass solar nebula. If there is a grain-concentrated
part in the disk, the relative velocity due to the lift force may dominate
there because of high collision rate.Comment: 9 pages, 4 figures. Accepted for publication in Earth, Planets and
Spac
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