4,786 research outputs found
Testing 2HDM at Muon Colliders
One very light neutral Higgs scalar with mass, say, below 40-50 GeV is still
allowed in the non-supersymmetric 2HDM (Model II), while the remaining
particles of the Higgs sector in this model have to be heavier. The possibility
of testing such a scenario at Muon Colliders is discussed.Comment: 6 pages, 4 Postscript figures, uses aipproc.sty. Presented at the
Workshop on Physics at the First Muon Collider and at the Front End of a Muon
Collider, Fermilab, November 199
Communities and classes in symmetric fractals
Two aspects of fractal networks are considered: the community structure and
the class structure, where classes of nodes appear as a consequence of a local
symmetry of nodes. The analysed systems are the networks constructed for two
selected symmetric fractals: the Sierpinski triangle and the Koch curve.
Communities are searched for by means of a set of differential equations.
Overlapping nodes which belong to two different communities are identified by
adding some noise to the initial connectivity matrix. Then, a node can be
characterized by a spectrum of probabilities of belonging to different
communities. Our main goal is that the overlapping nodes with the same spectra
belong to the same class
Combinatorial aspect of fashion
Simulations are performed according to the Axelrod model of culture
dissemination, with modified mechanism of repulsion. Previously, repulsion was
considered by Radillo-Diaz et al (Phys. Rev. E 80 (2009) 066107) as dependent
on a predefined threshold. Here the probabilities of attraction and repulsion
are calculated from the number of cells in the same states. We also investigate
the influence of some homogeneity, introduced to the initial state. As the
result of the probabilistic definition of repulsion, the ordered state
vanishes. A small cluster of a few percent of population is retained only if in
the initial state a set of agents is prepared in the same state. We conclude
that the modelled imitation is successful only with respect to agents, and not
only their features
Heavy quark photoproduction at THERA
Measurements of heavy quark production at a possible future facility,
THERA, would provide valuable information on the structure of the photon. QCD
cross-section predictions are made at LO for both charm and beauty production
and their sensitivity to current parametrisations of the photon parton
densities is investigated.Comment: 10 pages, 9 figures. To appear in "The THERA Book",
DESY-LC-REV-2001-062. IFT 2001/
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