18,122 research outputs found
Sensitivity to the Higgs sector of SUSY-seesaw models via LFV tau decays
Here we study and compare the sensitivity to the Higgs sector of the
SUSY-seesaw models via the LFV tau decays: tau-> 3 mu, tau->K^{+}K^{-}, tau->mu
eta and tau-> mu f_{0}. We emphasize that, at present, the two later channels
are the most efficient ones to test indirectly the Higgs particles.Comment: 4 pages, 3 figures, conference SUSY09 Boston (M.Herrero
Nonequilibrium Phase Transitions in Directed Small-World Networks
Many social, biological, and economic systems can be approached by complex
networks of interacting units. The behaviour of several models on small-world
networks has recently been studied. These models are expected to capture the
essential features of the complex processes taking place on real networks like
disease spreading, formation of public opinion, distribution of wealth, etc. In
many of these systems relations are directed, in the sense that links only act
in one direction (outwards or inwards). We investigate the effect of directed
links on the behaviour of a simple spin-like model evolving on a small-world
network. We show that directed networks may lead to a highly nontrivial phase
diagram including first and second-order phase transitions out of equilibrium.Comment: 4 pages, RevTeX format, 4 postscript figs, uses eps
Sustainability in the boardroom: An empirical examination of Dow Jones sustainability world index leaders
In recent years, there has been a virtual explosion of interest in corporate governance. Corporate scandals and the need to protect minority shareholders' interests, for example, are some of the reasons behind the development of corporate governance codes in numerous countries and corporations. At the same time, the concepts of "sustainable development", "corporate responsibility", and "corporate citizenship" have taken root in the business world. Although an extensive body of research treats the fields of corporate governance and sustainable development separately, less attention has been paid to the interaction between both fields. This paper attempts to bridge this gap by examining how corporate governance systems are evolving in order to integrate sustainable development thinking into them. We do so by analyzing the governance systems of the 18 corporations that are leading the market sectors considered by the Dow Jones Sustainability World Index (DJSWI). We present the results of our in depth analysis of the 18 cases and propose the Sustainable Corporate Governance Model that emerges from that analysis.Corporate governance; sustainable corporate governance; sustainable enterprise; sustainable development; business in society;
Higgs Boson Masses in the MSSM with Heavy Majorana Neutrinos
We present a full diagrammatic computation of the one-loop corrections from
the neutrino/sneutrino sector to the renormalized neutral CP-even Higgs boson
self-energies and the lightest Higgs boson mass, Mh, within the context of the
so-called MSSM-seesaw scenario. This consists of the Minimal Supersymmetric
Standard Model with the addition of massive right handed Majorana neutrinos and
their supersymmetric partners, and where the seesaw mechanism is used for the
lightest neutrino mass generation. We explore the dependence on all the
parameters involved, with particular emphasis in the role played by the heavy
Majorana scale. We restrict ourselves to the case of one generation of
neutrinos/sneutrinos. For the numerical part of the study, we consider a very
wide range of values for all the parameters involved. We find sizeable
corrections to Mh, which are negative in the region where the Majorana scale is
large (10^{13}-10^{15} GeV) and the lightest neutrino mass is within a range
inspired by data (0.1-1 eV). For some regions of the MSSM-seesaw parameter
space, the corrections to Mh are substantially larger than the anticipated
Large Hadron Collider precision.Comment: Latex, 50 pages, 15 figures, 6 tables. Discussion improved. Comments
and some new approximate formulae have been added. Published version on JHE
Automating decision making to help establish norm-based regulations
Norms have been extensively proposed as coordination mechanisms for both
agent and human societies. Nevertheless, choosing the norms to regulate a
society is by no means straightforward. The reasons are twofold. First, the
norms to choose from may not be independent (i.e, they can be related to each
other). Second, different preference criteria may be applied when choosing the
norms to enact. This paper advances the state of the art by modeling a series
of decision-making problems that regulation authorities confront when choosing
the policies to establish. In order to do so, we first identify three different
norm relationships -namely, generalisation, exclusivity, and substitutability-
and we then consider norm representation power, cost, and associated moral
values as alternative preference criteria. Thereafter, we show that the
decision-making problems faced by policy makers can be encoded as linear
programs, and hence solved with the aid of state-of-the-art solvers
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