6,899 research outputs found
Supersymmetric lepton flavour violation in a linear collider: the role of charginos
The occurrence of a significant amount of supersymmetric lepton flavour
violation at laboratory energies, through
mixing, has become a realistic possibility in the wake of the super-Kamiokande
atmospheric neutrino result. This effect can be observed in an e+e- linear
collider with the distinct final state tau+mu+ jets+E_T. We show that the pair
production of charginos can make an important contribution to this process and
has to be taken into account in addition to that of sneutrinos or charged
sleptons. Some case studies are presented with CM energies of 500 and 800 GeV
and integrated luminosities of 50, 500 and 1000 fb-1.Comment: 15 pages, latex, including 2 figure
Dark Matter in the USSM
We discuss the neutralino dark matter within classes of extended
supersymmetric models, referred to as the USSM, containing one additional SM
singlet Higgs plus an extra Z', together with their superpartners the singlino
and bino'.Comment: 4 pages, 3 figs. Talk given at LCWS08, Chicago, IL, USA,
11/16-20/200
Incremental Network Design with Minimum Spanning Trees
Given an edge-weighted graph and a set , the
incremental network design problem with minimum spanning trees asks for a
sequence of edges minimizing
where is the weight of a minimum spanning tree
for the subgraph and . We prove that this problem can be solved by a greedy
algorithm.Comment: 9 pages, minor revision based on reviewer comment
A reclaimer scheduling problem arising in coal stockyard management
We study a number of variants of an abstract scheduling problem inspired by
the scheduling of reclaimers in the stockyard of a coal export terminal. We
analyze the complexity of each of the variants, providing complexity proofs for
some and polynomial algorithms for others. For one, especially interesting
variant, we also develop a constant factor approximation algorithm.Comment: 26 page
Towards Guidelines for Preventing Critical Requirements Engineering Problems
Context] Problems in Requirements Engineering (RE) can lead to serious
consequences during the software development lifecycle. [Goal] The goal of this
paper is to propose empirically-based guidelines that can be used by different
types of organisations according to their size (small, medium or large) and
process model (agile or plan-driven) to help them in preventing such problems.
[Method] We analysed data from a survey on RE problems answered by 228
organisations in 10 different countries. [Results] We identified the most
critical RE problems, their causes and mitigation actions, organizing this
information by clusters of size and process model. Finally, we analysed the
causes and mitigation actions of the critical problems of each cluster to get
further insights into how to prevent them. [Conclusions] Based on our results,
we suggest preliminary guidelines for preventing critical RE problems in
response to context characteristics of the companies.Comment: Proceedings of the 42th Euromicro Conference on Software Engineering
and Advanced Applications, 201
Analytical and Numerical Treatment of the Mott--Hubbard Insulator in Infinite Dimensions
We calculate the density of states in the half-filled Hubbard model on a
Bethe lattice with infinite connectivity. Based on our analytical results to
second order in , we propose a new `Fixed-Energy Exact Diagonalization'
scheme for the numerical study of the Dynamical Mean-Field Theory. Corroborated
by results from the Random Dispersion Approximation, we find that the gap opens
at . Moreover, the density of states near the gap
increases algebraically as a function of frequency with an exponent
in the insulating phase. We critically examine other analytical
and numerical approaches and specify their merits and limitations when applied
to the Mott--Hubbard insulator.Comment: 22 pages, 16 figures; minor changes (one reference added, included
comparison with Falicov-Kimball model
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