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 $\mu^--e^+$ conversion, and the K decay, $K^-\to\pi^+\mu^-\mu^-.$ 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$_\nu$ in the $\approx$ MeV range) have been achieved. Results of the solar neutrino experiment SNO show clearly flavor transitions from $\nu_e$ to $\nu_{\mu,\tau}$. 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 $p \to K^+ \nu$ 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