826 research outputs found
On the Galois Lattice of Bipartite Distance Hereditary Graphs
We give a complete characterization of bipartite graphs hav- ing tree-like Galois lattices. We prove that the poset obtained by deleting bottom and top elements from the Galois lattice of a bipartite graph is tree-like if and only if the graph is a Bipartite Distance Hereditary graph. We show that the lattice can be realized as the containment relation among directed paths in an arborescence. Moreover, a compact encoding of Bipartite Distance Hereditary graphs is proposed, that allows optimal time computation of neighborhood intersections and maximal bicliques
CP Violations in Lepton Number Violation Processes and Neutrino Oscillations
We examine the constraints on the MNS lepton mixing matrix from the present
and future experimental data of the neutrino oscillation and lepton number
violation processes. We introduce a graphical representation of the CP
violation phases which appear in the lepton number violation processes such as
neutrinoless double beta decay, the conversion, and the K decay,
Using this graphical representation, we derive the
constraints on the CP violation phases in the lepton sector.Comment: 21pp, REVTeX, 9 Figure
Neutrino flavour relaxation or neutrino oscillations?
We propose the new mechanism of neutrino flavour relaxation to explain the
experimentally observed changes of initial neutrino flavour fluxes. The test of
neutrino relaxation hypothesis is presented, using the data of modern reactor,
solar and accelerator experiments. The final choice between the standard
neutrino oscillations and the proposed neutrino flavour relaxation model can be
done in future experiments
Implications of recent solar neutrino observations: an analysis of charged current data
We have analysed the recent results from the observation of charged current
\nu_e d \to e^- p p events from solar neutrinos by the Sudbury Neutrino
Observatory SNO assuming neutrino oscillations with three active flavours. The
data seem to prefer a low mass-squared difference and large mixing angle
solution (the so-called LOW solution) in (12) parameter space. However, when
combined with the Gallium charged current interaction data from Gallex and GNO,
distinct (1\sigma) allowed regions corresponding to the large mixing angle
(LMA) and small mixing angle (SMA) appear while the LOW solution is disfavoured
upto 3\sigma standard deviation. The physical electron neutrino survival
probability corresponding to these best fit solutions are then determined and
analysed for their energy dependence.Comment: 16 pages Latex file, with 5 epsf figures; one reference adde
Evaluating homophily in networks via HONTO (HOmophily Network TOol): a case study of chromosomal interactions in human PPI networks
It has been observed in different kinds of networks, such as social or biological ones, a typical behavior inspired by the general principle 'similarity breeds connections'. These networks are defined as homophilic as nodes belonging to the same class preferentially interact with each other. In this work, we present HONTO (HOmophily Network TOol), a user-friendly open-source Python3 package designed to evaluate and analyze homophily in complex networks. The tool takes in input from the network along with a partition of its nodes into classes and yields a matrix whose entries are the homophily/heterophily z-score values. To complement the analysis, the tool also provides z-score values of nodes that do not interact with any other node of the same class. Homophily/heterophily z-scores values are presented as a heatmap allowing a visual at-a-glance interpretation of results. AVAILABILITY AND IMPLEMENTATION: Tool's source code is available at https://github.com/cumbof/honto under the MIT license, installable as a package from PyPI (pip install honto) and conda-forge (conda install -c conda-forge honto), and has a wrapper for the Galaxy platform available on the official Galaxy ToolShed (Blankenberg et al., 2014) at https://toolshed.g2.bx.psu.edu/view/fabio/honto
Majorana Neutrino, the Size of Extra Dimensions, and Neutrinoless Double Beta Decay
The problem of Majorana neutrino mass generated in
Arkani-Hamed--Dimopoulos-Dvali model with n extra spatial dimensions is
discussed. Taking into account constraints on neutrino masses coming from
cosmological observations, it is possible to obtain lower limits on the size of
extra dimensions as large as 10^{-6} mm. In the case of n=4 it is easy to lower
the fundamental scale of gravity from the Planck energy to electroweak scale
\~TeV without imposing any additional constraints. A link between the half-life
of neutrinoless double beta decay and the size of extra dimensions is
discussed.Comment: 5 pages, 1 figure, using RevTEX. Units conversion correcte
Low Energy Neutrino Physics after SNO and KamLAND
In the recent years important discoveries in the field of low energy neutrino
physics (E in the MeV range) have been achieved. Results of the
solar neutrino experiment SNO show clearly flavor transitions from to
. In addition, the long standing solar neutrino problem is
basically solved. With KamLAND, an experiment measuring neutrinos emitted from
nuclear reactors at large distances, evidence for neutrino oscillations has
been found. The values for the oscillation parameters, amplitude and phase,
have been restricted. In this paper the potential of future projects in low
energy neutrino physics is discussed. This encompasses future solar and reactor
experiments as well as the direct search for neutrino masses. Finally the
potential of a large liquid scintillator detector in an underground laboratory
for supernova neutrino detection, solar neutrino detection, and the search for
proton decay is discussed.Comment: Invited brief review, World Scientific Publishing Compan
New model for the neutrino mass matrix
I suggest a model based on a softly broken symmetry L_e - L_mu - L_tau and on
Babu's mechanism for two-loops radiative generation of the neutrino masses. The
model predicts that one of the physical neutrinos (nu_3) is massless and that
its component along the nu_e direction (U_e3) is zero. Moreover, if the
soft-breaking term is assumed to be very small, then the vacuum oscillations of
nu_e have almost maximal amplitude and solve the solar-neutrino problem. New
scalars are predicted in the 10 TeV energy range, and a breakdown of e-mu-tau
universality should not be far from existing experimental bounds.Comment: 7 pages including 3 figure
Neutrino Experiments: Status, Recent Progress, and Prospects
Neutrino physics has seen an explosion of activity and new results in the
last decade. In this report the current state of the field is summarized, with
a particular focus on progress in the last two years. Prospects for the near
term (roughly 5 years) are also described.Comment: 14 pages, 10 figures, proceedings of plenary talk at EPS HEP 2007
Conference, Manchester, UK. Updated with citation added to Figure 1
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