3,166 research outputs found

### Neutrino oscillograms of the Earth and CP violation in neutrino oscillations

An analysis of 3-flavour neutrino oscillations inside the Earth is presented
in terms of the oscillograms -- contour plots of oscillation probabilities in
the plane neutrino energy -- nadir angle. Special attention is paid to CP
violation in neutrino oscillations in the Earth.Comment: Talk given at Neutrino Oscillations Workshop NOW2008, 3 pages, 2
figure

### Seesaw mechanism and the neutrino mass matrix

The seesaw mechanism of neutrino mass generation is analysed under the
following assumptions: (1) minimal seesaw with no Higgs triplets, (2)
hierarchical Dirac masses of neutrinos, (3) large lepton mixing primarily or
solely due to the mixing in the right-handed neutrino sector, and (4) unrelated
Dirac and Majorana sectors of neutrino masses. It is shown that large mixing
governing the dominant channel of the atmospheric neutrino oscillations can be
naturally obtained and that this constrained seesaw mechanism favours the
normal mass hierarchy for the light neutrinos leading to a small $U_{e3}$ entry
of the lepton mixing matrix and a mass scale of the lightest right handed
neutrino $M\simeq 10^{10} - 10^{11}$ GeV. Any of the three main neutrino
oscillation solutions to the solar neutrino problem can be accommodated. The
inverted mass hierarchy and quasi-degeneracy of neutrinos are disfavoured in
our scheme.Comment: LaTeX, 3 pages, no figures. Talk given at 6th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 99), September 6-10,
1999, Paris, Franc

### Pontecorvo's Original Oscillations Revisited

We show that a left-handed neutrino $\nu_L$ can oscillate into its $CP$-
conjugated state $\bar{\nu}_R$ with maximal amplitude, in direct analogy with
$K^0-\bar{K}^0$ oscillations. Peculiarities of such oscillations under
different conditions are studied.Comment: LaTeX, 14 pages, 1 figure (not included but available upon request by
fax or ordinary mail), SISSA 9/93/EP, IC/93/1

### Fourier Analysis of the Parametric Resonance in Neutrino Oscillations

Parametric enhancement of the appearance probability of the neutrino
oscillation under the inhomogeneous matter is studied. Fourier expansion of the
matter density profile leads to a simple resonance condition and manifests that
each Fourier mode modifies the energy spectrum of oscillation probability at
around the corresponding energy; below the MSW resonance energy, a large-scale
variation modifies the spectrum in high energies while a small-scale one does
in low energies. In contrast to the simple parametric resonance, the
enhancement of the oscillation probability is itself an slow oscillation as
demonstrated by a numerical analysis with a single Fourier mode of the matter
density. We derive an analytic solution to the evolution equation on the
resonance energy, including the expression of frequency of the slow
oscillation.Comment: 12 pages, 3 color figures, LaTeX, elsarticle.st

### Construction of Exotic Smooth Structures

In this article, we construct infinitley many simply connected, nonsymplectic
and pairwise nondiffeomorphic 4-manifolds starting from E(n) and applying the
sequence of knot surgery, ordinary blowups and rational blowdown. We also
compute the Seiberg-Witten invariants of these manifolds.Comment: 10 page

### On groups of diffeomorphisms of the interval with finitely many fixed points II

In [6], it is proved that any subgroup of $\mathrm{Diff}_{+}^{\omega }(I)$
(the group of orientation preserving analytic diffeomorphisms of the interval)
is either metaabelian or does not satisfy a law. A stronger question is asked
whether or not the Girth Alternative holds for subgroups of
$\mathrm{Diff}_{+}^{\omega }(I)$. In this paper, we answer this question
affirmatively for even a larger class of groups of orientation preserving
diffeomorphisms of the interval where every non-identity element has finitely
many fixed points. We show that every such group is either affine (in
particular, metaabelian) or has infinite girth. The proof is based on
sharpening the tools from the earlier work [1]

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