Contact Interactions Probe Effective Dark Matter Models at the LHC

Effective field theories provide a simple framework for probing possible dark matter (DM) models by reparametrising full interactions into a reduced number of operators with smaller dimensionality in parameter space. In many cases these models have four particle vertices, e.g. qqXX, leading to the pair production of dark matter particles, X, at a hadron collider from initial state quarks, q. In this analysis we show that for many fundamental DM models with s-channel DM couplings to qq-pairs, these effective vertices must also produce quark contact interactions (CI) of the form qqqq. The respective effective couplings are related by the common underlying theory which allows one to translate the upper limits from one coupling to the other. We show that at the LHC, the experimental limits on quark contact interactions give stronger translated limits on the DM coupling than the experimental searches for dark matter pair production.Comment: 6 pages, 3 figure

Regional cooperation efforts in the Mekong River Basin: mitigating river-related security threats and promoting regional development

"Die Entwicklung grenzüberschreitender Flüsse wird oft mit Konflikten oder gar Kriegen um Wasser assoziiert. Wie jedoch die Entwicklung im Mekong-Becken zeigt, waren die vergangenen Jahrzehnte nicht nur von Kooperation gezeichnet, sondern Flussbeckenorganisationen konnten außerdem dazu beitragen, weitreichendere Kooperationsstrukturen zu entwickeln, die sich auf andere Politikfelder ausdehnen. Dieser Artikel beschäftigt sich mit dem Beitrag der Mekong River Commission (MRC) und der Greater Mekong Sub-Region (GMS) zur nachhaltigen Entwicklung in der Mekong Region sowie zur Förderung allgemeiner regionaler Kooperation im Festländischen Südostasien." (Autorenreferat)"The development of international rivers is often perceived as leading to conflicts or even water wars. However, as the development of the Mekong River shows, cooperation has not only prevailed in the last decades, but River Basin Organizations (RBOs), established to mitigate river-related conflicts and/ or develop the river basin, have also contributed to the emergence of more general cooperation structures, mainly by creating spill-over effects in other issue-areas, bringing cooperation to policy fields beyond the river itself. This article assesses the contribution of the Mekong River Commission (MRC) and the Greater Mekong Sub-Region (GMS) to the sustainable development of the Mekong Region as well as to the promotion of regional cooperation in mainland South-East Asia in general." (author's abstract

Exploratory Search on Mobile Devices

The goal of this thesis is to provide a general framework (MobEx) for exploratory search especially on mobile devices. The central part is the design, implementation, and evaluation of several core modules for on-demand unsupervised information extraction well suited for exploratory search on mobile devices and creating the MobEx framework. These core processing elements, combined with a multitouch - able user interface specially designed for two families of mobile devices, i.e. smartphones and tablets, have been finally implemented in a research prototype. The initial information request, in form of a query topic description, is issued online by a user to the system. The system then retrieves web snippets by using standard search engines. These snippets are passed through a chain of NLP components which perform an ondemand or ad-hoc interactive Query Disambiguation, Named Entity Recognition, and Relation Extraction task. By on-demand or ad-hoc we mean the components are capable to perform their operations on an unrestricted open domain within special time constraints. The result of the whole process is a topic graph containing the detected associated topics as nodes and the extracted relation ships as labelled edges between the nodes. The Topic Graph is presented to the user in different ways depending on the size of the device she is using. Various evaluations have been conducted that help us to understand the potentials and limitations of the framework and the prototype

Automatised Constraints on New Physics at the LHC and Beyond

In this thesis, we discuss the development and use cases of the public software CheckMATE which is designed to allow for easy tests of theories beyond the Standard Model against current results from the Large Hadron Collider (LHC). We illustrate the general functionality of this tool and provide hands-on examples to explain how it can be used to test results from the ATLAS and CMS experiments. In addition, we explain how new analyses can be conveniently added to the existing framework. This tool is then used to project a search for monojet final states to a high luminosity LHC with a centre-of-mass energy of 14 TeV. Here, our prospective analysis is used to determine the expected sensitivity to a Higgs Portal scenario which couples the Standard Model to a hidden sector via an invisibly decaying second heavy scalar. We show that complementary bounds to those derived from Higgs boson searches in 8 TeV LHC data can be set, however only if a significant reduction of the current systematic uncertainties for the background estimates of such a search can be achieved. Furthermore, we use CheckMATE and its large set of implemented searches for natural Supersymmetry to show how an extension of the Minimal Supersymmetric Standard Model by an additional chiral gauge singlet typically reduces the LHC sensitivity. In the context of R-parity violating Supersymmetry, we go beyond CheckMATE and the LHC and derive how the expected sensitivity of the proposed fixed-target experiment SHiP to observe long-lived neutralinos produced via rare Standard Model meson decays can significantly improve existing bounds from low energy observations

the role of river basin organizations

Hydrological changes such as variability in water availability, extreme events like floods and droughts or water pollution pose a serious challenge to effective management of internationally shared water resources – no matter whether they are induced by climate change, large infrastructure projects in the river basin or other forms of environmental change. To address these management challenges, many states have established transboundary River Basin Organization (RBOs). The purpose of this paper is to investigate the ability of such RBOs to respond to exogenous environmental and man-made changes by identifying institutional mechanisms and management practices that have been established by the respective institutions or their member states to react to transformations in the basins’ environment. Drawing on the literature of neoinstitutionalist theory and hydropolitics approaches, a comprehensive analytical framework is being developed. It consists of the following determinants of adaptation capacity: Membership structure, functional scope, decision-making mechanisms, data and information sharing, dispute-resolution mechanisms, finances and donor support. Subsequently, the framework is applied to two case studies, the Okavango and the Mekong River Basin. The paper concludes that the adaptation capacity of RBOs depends significantly on these factors, however, further research to quantify their respective impact and to test hypotheses on a larger number of cases is needed

Illuminating Dark Matter at the ILC

The WIMP (weakly interacting massive particle) paradigm for dark matter is currently being probed via many different experiments. Direct detection, indirect detection and collider searches are all hoping to catch a glimpse of these elusive particles. Here, we examine the potential of the ILC (International Linear Collider) to shed light on the origin of dark matter. By using an effective field theory approach we are also able to compare the reach of the ILC with that of the other searches. We find that for low mass dark matter (< 10 GeV), the ILC offers a unique opportunity to search for WIMPS beyond any other experiment. In addition, if dark matter happens to only couple to leptons or via a spin dependent interaction, the ILC can give an unrivalled window to these models. We improve on previous ILC studies by constructing a comprehensive list of effective theories that allows us to move beyond the non-relativistic approximation.Comment: 26 page