Extracting SUSY parameters from LHC measurements using Fittino

We show that presently available precision data are in good agreement with supersymmetry at a mass scale below 1 TeV. Using a SUSY point close to the best fit to present data, we give a projection of the capabilities of the LHC to constrain SUSY models and their parameters as function of the accumulated luminosity.Comment: 4 pages, contribution to the proceedings of the 17th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY09), Northeastern University, Boston, MA, USA, June 200

A Challenge for the G20: Globally Stipulated Debt Brakes and Transnational Independent Fiscal Supervisory Councils

Debt-to-GDP ratios have grown to unprecedented levels in many industrialized economies. This requires disciplined consolidation efforts which are, however, supposed to come now at the wrong time with the economic recovery being fragile. Against this background, we call for a global debt brake following the German example and discuss the political progress achieved at the most recent Euro and G20 summits. The agreement on the debt brake should be binding and hence be fixed in national constitutions and monitored by independent transnational fiscal councils. The fiscal councils could be located at the ESM and the IMF and should conduct a regular evaluation of national budget plans. In an economic and political environment which is characterized by large uncertainties concerning economic prospects and the fear of a potential spreading of the sovereign debt crisis, a global debt brake in combination with an independent transnational supervisory council would send a credible signal that a reduction of sovereign debt to sustainable levels is not further delayed into the future. The new fiscal policy framework thus leaves enough room for discretionary fiscal policy and the workings of automatic stabilizers in an economic downturn.debt brake, fiscal council, G20

A Challenge for the G20: Globally Stipulated Debt Brakes and Transnational Independent Fiscal Supervisory Councils

Debt-to-GDP ratios have grown to unprecedented levels in many industrialized economies. This requires disciplined consolidation efforts which are, however, supposed to come now at the wrong time with the economic recovery being fragile. The countries forming the G20 need to make sure the long-term sustainability of public finances. Not least, this is indispensable in order to avoid a further spreading of the sovereign debt crisis. Against this background, we call for a global debt brake following the Swiss or German example which should be agreed upon in Cannes in early November 2011. The agreement on the debt brake should be binding – in contrast to previous expressions made at the G20-level to reduce government debt, as, for example, the Seoul Action Plan is lacking any binding character. Therefore, the debt brakes should be fixed in national constitutions and monitored by independent transnational fiscal councils. The fiscal councils could be located at the European Stability Mechanism (ESM) and the International Monetary Fund (IMF) and should conduct a regular evaluation of national budget plans in order to ensure that they meet the requirements stipulated by the debt brake. Through this global monitoring process, an early warning system could be developed with the aim to avoid sovereign debt crises and the resulting contagion risks among highly indebted countries in the future. In an economic and political environment which is characterized by large uncertainties concerning economic prospects and the fear of a potential spreading of the sovereign debt crisis, a global debt brake in combination with an independent transnational supervisory council would send a credible signal that a reduction of sovereign debt to sustainable levels is not further delayed into the future. Moreover, a well-designed debt brake ensures that the general government budget is balanced over the business cycle. Consequently, it is a more efficient instrument than the former Stability and Growth Pact for the Eurozone which in fact stipulated a ceiling for the budget deficit, but whose requirements regarding budget surpluses in good times were insufficient. This asymmetry is eliminated by those debt brakes which are in force in Switzerland and Germany. The new fiscal policy framework thus leaves enough room for discretionary fiscal policy and the workings of automatic stabilizers in an economic downturn.debt brake, fiscal council, G20

A New and Unifying Approach to Spin Dynamics and Beam Polarization in Storage Rings

With this paper we extend our studies [1] on polarized beams by distilling tools from the theory of principal bundles. Four major theorems are presented, one which ties invariant fields with the notion of normal form, one which allows one to compare different invariant fields, and two that relate the existence of invariant fields to the existence of certain invariant sets and relations between them. We then apply the theory to the dynamics of spin-1/2 and spin-1 particles and their density matrices describing statistically the particle-spin content of bunches. Our approach thus unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics. This unifying aspect of our approach relates the examples elegantly and uncovers relations between the various underlying dynamical systems in a transparent way

An Informal Summary of a New Formalism for Classifying Spin-Orbit Systems Using Tools Distilled from the Theory of Bundles

We give an informal summary of ongoing work which uses tools distilled from the theory of fibre bundles to classify and connect invariant fields associated with spin motion in storage rings. We mention four major theorems. One ties invariant fields with the notion of normal form, the second allows comparison of different invariant fields and the two others tie the existence of invariant fields to the existence of certain invariant sets. We explain how the theorems apply to the spin dynamics of spin-$1/2$ and spin-$1$ particles. Our approach elegantly unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics and suggests an avenue for addressing the question of the existence of the invariant spin field.Comment: Based on a presentation at Spin2014, The 21st International Symposium on Spin Physics, Beijing, China, October 2014. To be published in the International Journal of Modern Physics, Conference Serie

A detailed and unified treatment of spin-orbit systems using tools distilled from the theory of bundles

We return to our study \cite{BEH} of invariant spin fields and spin tunes for polarized beams in storage rings but in contrast to the continuous-time treatment in \cite{BEH}, we now employ a discrete-time formalism, beginning with the $\rm{Poincar\acute{e}}$ maps of the continuous time formalism. We then substantially extend our toolset and generalize the notions of invariant spin field and invariant frame field. We revisit some old theorems and prove several theorems believed to be new. In particular we study two transformation rules, one of them known and the other new, where the former turns out to be an $SO(3)$-gauge transformation rule. We then apply the theory to the dynamics of spin-$1/2$ and spin-$1$ particle bunches and their density matrix functions, describing semiclassically the particle-spin content of bunches. Our approach thus unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics. This unifying aspect of our approach relates the examples elegantly and uncovers relations between the various underlying dynamical systems in a transparent way. As in \cite{BEH}, the particle motion is integrable but we now allow for nonlinear particle motion on each torus. Since this work is inspired by notions from the theory of bundles, we also provide insight into the underlying bundle-theoretic aspects of the well-established concepts of invariant spin field, spin tune and invariant frame field. Since we neglect, as is usual, the Stern-Gerlach force, the underlying principal bundle is of product formso that we can present the theory in a fashion which does not use bundle theory. Nevertheless we occasionally mention the bundle-theoretic meaningof our concepts and we also mention the similarities with the geometrical approach to Yang-Mills Theory