12,398 research outputs found
Radical Conservatism and Nucleon Decay
Unification of couplings, observation of neutrino masses in the expected
range, and several other considerations confirm central implications of
straightforward gauge unification based on SO(10) or a close relative and
incorporating low-energy supersymmetry. The remaining outstanding consequence
of this circle of ideas, yet to be observed, is nucleon instability. Clearly,
we should aspire to be as specific as possible regarding the rate and form of
such instability. I argue that not only esthetics, but also the observed
precision of unification of couplings, favors an economical symmetry-breaking
(Higgs) structure. Assuming this, one can exploit its constraints to build
reasonably economical, overconstrained yet phenomenologically viable models of
quark and lepton masses. Putting it all together, one arrives at reasonably
concrete, hopeful expectations regarding nucleon decay. These expectations are
neither ruled out by existing experiments, nor hopelessly inaccessible.Comment: LaTeX, 14 pages, 4 figures; moved reference, corrected typo, improved
two figure
An interactive semantics of logic programming
We apply to logic programming some recently emerging ideas from the field of
reduction-based communicating systems, with the aim of giving evidence of the
hidden interactions and the coordination mechanisms that rule the operational
machinery of such a programming paradigm. The semantic framework we have chosen
for presenting our results is tile logic, which has the advantage of allowing a
uniform treatment of goals and observations and of applying abstract
categorical tools for proving the results. As main contributions, we mention
the finitary presentation of abstract unification, and a concurrent and
coordinated abstract semantics consistent with the most common semantics of
logic programming. Moreover, the compositionality of the tile semantics is
guaranteed by standard results, as it reduces to check that the tile systems
associated to logic programs enjoy the tile decomposition property. An
extension of the approach for handling constraint systems is also discussed.Comment: 42 pages, 24 figure, 3 tables, to appear in the CUP journal of Theory
and Practice of Logic Programmin
Are Electrons Oscillating Photons, Oscillating “Vacuum," or Something Else? The 2015 Panel Discussion: An Unprecedented Engineering Opportunity: A Dynamical Linear Theory of Energy as Light and Matter
Platform: What physical attributes separate EM waves, of the enormous band of radio to visible to x-ray, from the high energy narrow band of gamma-ray? From radio to visible to x-ray, telescopes are designed based upon the optical imaging theory; which is an extension of the Huygens-Fresnel diffraction integral. Do we understand the physical properties of gamma rays that defy us to manipulate them similarly? One demonstrated unique property of gamma rays is that they can be converted to elementary particles (electron and positron pair); or a particle-antiparticle pair can be converted into gamma rays. Thus, EM waves and elementary particles, being inter-convertible; we cannot expect to understand the deeper nature of light without succeeding to find structural inter-relationship between photons and particles. This topic is directly relevant to develop a deeper understanding of the nature of light; which will, in turn, help our engineers to invent better optical instruments
Enhanced sharing analysis techniques: a comprehensive evaluation
Sharing, an abstract domain developed by D. Jacobs and A. Langen for the analysis of logic
programs, derives useful aliasing information. It is well-known that a commonly used core
of techniques, such as the integration of Sharing with freeness and linearity information, can
significantly improve the precision of the analysis. However, a number of other proposals for
refined domain combinations have been circulating for years. One feature that is common
to these proposals is that they do not seem to have undergone a thorough experimental
evaluation even with respect to the expected precision gains.
In this paper we experimentally
evaluate: helping Sharing with the definitely ground variables found using Pos, the domain
of positive Boolean formulas; the incorporation of explicit structural information; a full
implementation of the reduced product of Sharing and Pos; the issue of reordering the
bindings in the computation of the abstract mgu; an original proposal for the addition of
a new mode recording the set of variables that are deemed to be ground or free; a refined
way of using linearity to improve the analysis; the recovery of hidden information in the
combination of Sharing with freeness information. Finally, we discuss the issue of whether
tracking compoundness allows the computation of more sharing information
Standard Coupling Unification in SO(10), Hybrid Seesaw Neutrino Mass and Leptogenesis, Dark Matter, and Proton Lifetime Predictions
We discuss gauge coupling unification of the SM descending directly from
SO(10) while providing solutions to the three outstanding problems: neutrino
masses, dark matter, and the baryon asymmetry of the universe. Conservation of
matter parity as gauged discrete symmetry in the model calls for high-scale
spontaneous symmetry breaking through Higgs representation. This
naturally leads to the hybrid seesaw formula for neutrino masses mediated by
heavy scalar triplet and right-handed neutrinos. The seesaw formula predicts
two distinct patterns of RH masses, one hierarchical and another not so
hierarchical (or compact) when fitted with the neutrino oscillation data.
Predictions of the baryon asymmetry via leptogenesis are investigated through
the decays of both the patterns of RH masses. A complete flavor analysis
has been carried out to compute CP-asymmetries and solutions to Boltzmann
equations have been utilized to predict the baryon asymmetry. The additional
contribution to vertex correction mediated by the heavy left-handed triplet
scalar is noted to contribute as dominantly as other Feynman diagrams. We have
found successful predictions of the baryon asymmetry for both the patterns of
RH masses. The triplet fermionic dark matter at the TeV scale carrying
even matter parity is naturally embedded into the non-standard fermionic
representation of SO(10). In addition to the triplet scalar and the
triplet fermion, the model needs a nonstandard color octet fermion of mass
GeV to achieve precision gauge coupling unification. Threshold
corrections due to superheavy components of and other representations
are estimated and found to be substantial. It is noted that the proton life
time predicted by the model is accessible to the ongoing and planned
experiments over a wide range of parameter space.Comment: 58 pages PDFLATEX, 19 Figures, Revised as suggested by JHEP Revie
Supersymmetric SO(10) for fermion masses and mixings: rank-1 structures of flavour
We consider a supersymmetric SO(10) model with a SU(3) symmetry of flavour in
which fermion masses emerge via the see-saw mixing with superheavy fermions in
16+16bar representations. In this model the dangerous D=5 operators of proton
decay are naturally suppressed and flavour-changing supersymmetric effects are
under control. The mass matrices for all fermion types (up and down quarks,
charged leptons as well as neutrinos) appear in the form of combinations of
three rank-1 matrices, common to all types of fermions, with different
coefficients that are successive powers of small parameters, related to each
other by SO(10) symmetry properties. Two versions of the model are considered,
in which approximate grand unification of masses takes place between quarks and
leptons of the first family (with very small \tan\beta) or for the ones of the
second family (predicting moderate \tan\beta ~ 7-8). The second version
exhibits an interesting mechanism of unification of the determinants of the
Yukawa matrices of all types of fermions at the GUT scale and it provides a
perfect fit of the known data for fermion masses, mixing and CP-violation. It
predicts a hierarchical pattern of neutrino masses with non-zero theta_e3,
within 2-7 degrees. In addition, it predicts the correct sign of the baryon
asymmetry of the Universe via the leptogenesys scenario.Comment: 30 Pages, 3 figures. Clarified comments on neutrino scales and on
universal seesaw, updated references. Version appeared on JHE
The Country-specific Organizational and Information Architecture of ERP Systems at Globalised Enterprises
The competition on the market forces companies to adapt to the changing environment. Most recently, the economic and financial crisis has been accelerating the alteration of both business and IT models of enterprises. The forces of globalization and internationalization motivate the restructuring of business processes and consequently IT processes. To depict the changes in a unified framework, we need the concept of Enterprise Architecture as a theoretical approach that deals with various tiers, aspects and views of business processes and different layers of application, software and hardware systems. The paper outlines a wide-range theoretical background for analyzing the re-engineering and re-organization of ERP systems at international or transnational companies in the middle-sized EU member states. The research carried out up to now has unravelled the typical structural changes, the models for internal business networks and their modification that reflect the centralization, decentralization and hybrid approaches. Based on the results obtained recently, a future research program has been drawn up to deepen our understanding of the trends within the world of ERP systems.Information System; ERP; Enterprise Resource Planning; Enterprise Architecture; Globalization; Centralization; Decentralization; Hybrid
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