85 research outputs found
Neutrino Mixing from Wilson Lines in Warped Space
We consider the generation of the hierarchical charged lepton spectrum and
anarchic neutrino masses and mixing angles in warped extra dimensional models
with Randall-Sundrum metric. We have classified all possible cases giving rise
to realistic spectra for both Dirac and Majorana neutrinos. An anarchic
neutrino spectrum requires a convenient bulk symmetry broken by boundary
conditions on both UV and IR branes. We have in particular considered the case
of Majorana neutrinos with a continuous bulk symmetry. To avoid unwanted
massless extra gauge bosons the 4D group should be empty. If the 4D coset is
not vanishing it can provide a Wilson Line description of the neutrino Majorana
mass matrix. We have studied an example based on the bulk gauge group U(3)_{L}
\otimes U(3)_{N} \otimes_{i} U(1)_{E^i} with the Wilson Line in SO(3)_{N}
satisfying all required conditions. A \chi^2-fit to experimental data exhibits
the 95% CL region in the parameter space with no fine-tuning. As a consequence
of the symmetries of the theory there is no tree-level induced lepton flavor
violation and so one-loop processes are consistent with experimental data for
KK-modes about a few TeV. The model is easily generalizable to models with IR
deformed metrics with similar conclusions.Comment: 28 pages, 9 eps plots, uses axodraw; v2 Title changed, comments on
phenomenology added, version to be published in JHE
Risk governance in organizations
Dieses Buch dokumentiert 10 Jahre Risk-Governance-Forschung an der Universität Siegen. In 50 Beiträgen reflektieren Forscher und Praktiker Risk Governance vor dem Hintergrund ihrer eigenen Forschungen und/oder Erfahrungen und geben jeweils einen Entwicklungsimpuls für die Zukunft der Risk Governance. Das Buch zeigt die große Bandbreite und Tiefe des Forschungsgebietes auf und diskutiert Grundannahmen, Implementierungsfragen, die Rolle der Risk Governance als Transformationsmotor, ihre Wirkung in den verschiedenen betrieblichen Funktionen, Entwicklungsperspektiven und den Beitrag der Risk Governance zu einer nachhaltigen Ausrichtung von Unternehmen.This book documents 10 years of risk governance research at the University of Siegen. In 50 contributions, researchers and practitioners reflect on risk governance against the background of their own research and/or experience and provide a development impetus for the future of risk governance. The book shows the wide range and depth of the research field and discusses basic assumptions, implementation issues, the role of risk governance as transformation engine, its impact in the various operational functions, development perspectives, and the contribution of risk governance to a sustainable orientation of companies
Quantum key distribution with hacking countermeasures and long term field trial
Quantum key distribution's (QKD's) central and unique claim is information theoretic security. However there is an increasing understanding that the security of a QKD system relies not only on theoretical security proofs, but also on how closely the physical system matches the theoretical models and prevents attacks due to discrepancies. These side channel or hacking attacks exploit physical devices which do not necessarily behave precisely as the theory expects. As such there is a need for QKD systems to be demonstrated to provide security both in the theoretical and physical implementation. We report here a QKD system designed with this goal in mind, providing a more resilient target against possible hacking attacks including Trojan horse, detector blinding, phase randomisation and photon number splitting attacks. The QKD system was installed into a 45 km link of a metropolitan telecom network for a 2.5 month period, during which time the system operated continuously and distributed 1.33 Tbits of secure key data with a stable secure key rate over 200 kbit/s. In addition security is demonstrated against coherent attacks that are more general than the collective class of attacks usually considered
Microneedles: A New Frontier in Nanomedicine Delivery
This review aims to concisely chart the development of two individual research fields, namely nanomedicines, with specific emphasis on nanoparticles (NP) and microparticles (MP), and microneedle (MN) technologies, which have, in the recent past, been exploited in combinatorial approaches for the efficient delivery of a variety of medicinal agents across the skin. This is an emerging and exciting area of pharmaceutical sciences research within the remit of transdermal drug delivery and as such will undoubtedly continue to grow with the emergence of new formulation and fabrication methodologies for particles and MN. Firstly, the fundamental aspects of skin architecture and structure are outlined, with particular reference to their influence on NP and MP penetration. Following on from this, a variety of different particles are described, as are the diverse range of MN modalities currently under development. The review concludes by highlighting some of the novel delivery systems which have been described in the literature exploiting these two approaches and directs the reader towards emerging uses for nanomedicines in combination with MN
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