16,783 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
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
Radiative corrections to from three generations of Majorana neutrinos and sneutrinos
In this work we study the radiative corrections to the mass of the lightest
Higgs boson of the MSSM from three generations of Majorana neutrinos and
sneutrinos. The spectrum of the MSSM is augmented by three right handed
neutrinos and their supersymmetric partners. A seesaw mechanism of type I is
used to generate the physical neutrino masses and oscillations that we require
to be in agreement with present neutrino data. We present a full one-loop
computation of these Higgs mass corrections, and analyze in full detail their
numerical size in terms of both the MSSM and the new (s)neutrino parameters. A
critical discussion on the different possible renormalization schemes and their
implications is included.Comment: 42 pages, 39 figures, 1 appendix, version published in AHE
The emergence of altruism as a social norm
Expectations, exerting influence through social norms, are a very strong candidate to explain how complex societies function. In the Dictator game (DG), people expect generous behavior from others even when they cannot enforce any sharing of the pie. Here we assume that people donate following their expectations, and that they update their expectation after playing a DG by reinforcement learning to construct a model that explains the main experimental results in the DG. Full agreement with the experimental results is reached when some degree of mismatch between expectations and donations is added into the model. These results are robust against the presence of envious agents, but affected if we introduce selfish agents that do not update their expectations. Our results point to social norms being on the basis of the generous behavior observed in the DG and also to the wide applicability of reinforcement learning to explain many strategic interactions
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