NLO automated tools for QCD and beyond

Theoretical predictions for scattering processes with multi-particle final states at next-to-leading order (NLO) in perturbative QCD are essential to fully exploit the physics potential of present and future high-energy colliders. The status of NLO QCD calculations and tools is reviewed.Comment: 13 pages, 2 tables, to appear in the proceedings of Linear Collider 2011 (Understanding QCD at linear colliders in searching for old and new physics), 12-16 September 2011, ECT*, Trento, Italy; added reference

Parting with Illusions: Developing a Realistic Approach to Relations with Russia

A review of America's post-Soviet strategy toward Russia is long overdue. The illusions that once guided policy are now at an end. What is needed is a dispassionate approach to Russia, wherein Americans would neither magnify nor excuse the virtues and vices of the Russian Federation but would accept the following realities: Russia is unlikely to become integrated into the Euro-Atlantic community and is unwilling to adjust its foreign policy priorities accordingly; There is broad-based support within Russia for the direction in which Vladimir Putin has taken the country;Russia has undergone a genuine -- if limited -- recovery from the collapse of the 1990s; Washington lacks sufficient leverage to compel Russian acquiescence to its policy preferences; and On a number of critical foreign policy issues, there is no clear community of interests that allows for concepts of "selective partnership" to be effective. Any approach to Russia must be based on realistic expectations about the choices confronting Washington. The United States has two options. It can forgo the possibility of Russian assistance in achieving its key foreign policy priorities in an effort to retain complete freedom of action vis-a-vis Moscow. Or it can prioritize its objectives and negotiate a series of quid pro quos with Russia. The latter choice, however, cannot be indefinitely postponed. Seeking an accommodation with Russia is more likely to guarantee American success in promoting its core national interests while minimizing costs -- but will require U.S. policymakers to accept limits on what can be demanded of Russia

Plane turbulent buoyant jets. Part 2. Turbulence structure

The turbulence structure of a plane vertical buoyant jet in the transition state from jet-like to plume-like growth is the object of this investigation. The ambient fluid is of uniform density and motionless except for the flow induced by the jet. An analysis of the turbulence energy equation reveals that the production of turbulent energy by the buoyancy forces relative to the production by the shear stress increases as the jet Richardson number increases, and becomes constant for a plume-like buoyant jet. A systematic set of experiments was carried out to examine the turbulence structure for a wide range of initial Richardson numbers, extending from a value appropriate to a jet-like flow (very close to zero) to that appropriate for a plume-like flow (approximately 0·6). Fast-response thermistors and a laser-Doppler velocimeter were used to measure the buoyant jet's temperature and velocity respectively. The temperature and velocity data were recorded magnetically in digital form and subsequently processed to extract both mean and fluctuating values. The turbulence intensity and the probability density distribution of the temperature and velocity fluctuations, the maximum and minimum temperature, the intermittency, and the frequency of crossing of the hot/cold and the cold/hot interface of a buoyant jet were investigated. It was determined that the intensity of temperature and velocity fluctuations increases with increasing Richardson number. An explanation is suggested for the large-scale vortices observed in a plume

A note on the spreading rate and virtual origin of a plane turbulent jet

The reported experimental coefficients describing the spreading rate and virtual origin of a plane turbulent jet exhibit substantial scatter. The hypothesis is made that the basic reason for these variations is that the growth of the jet is not linear on a large scale. Existing experimental results are used to support this hypothesis

On Fragments and Geometry: The International Legal Order as Metaphor and How it Matters

This article engages the narrative of fragmentation in international law by asserting that legal academics and professionals have failed to probe more deeply into ‘fragmentation’ as a concept and, more specifically, as a spatial metaphor. The contention here is that however central fragmentation has been to analyses of contemporary international law, this notion has been conceptually assumed, ahistorically accepted and philosophically under-examined. The ‘fragment’ metaphor is tied historically to a cartographic rationality – and thus ‘reality’ – of all social space being reducible to a geometric object and, correspondingly, a planimetric map. The purpose of this article is to generate an appreciation among international lawyers that the problem of ‘fragmentation’ is more deeply rooted in epistemology and conceptual history. This requires an explanation of how the conflation of social space with planimetric reduction came to be constructed historically and used politically, and how that model informs representations of legal practices and perceptions of ‘international legal order’ as an inherently absolute and geometric. This implies the need to dig up and expose background assumptions that have been working to precondition a ‘fragmented’ characterization of worldly space. With the metaphor of ‘digging’ in mind, I draw upon Michel Foucault’s ‘archaeology of knowledge’ and, specifically, his assertion that epochal ideas are grounded by layers of ‘obscure knowledge’ that initially seem unrelated to a discourse. In the case of the fragmentation narrative, I argue obscure but key layers can be found in the Cartesian paradigm of space as a geometric object and the modern States’ imperative to assert (geographic) jurisdiction. To support this claim, I attempt to excavate the fragment metaphor by discussing key developments that led to the production and projection of geometric and planimetric reality since the 16th century

Asymmetric Price Transmission in Supply Function Equilibrium, Carbon Prices and the German Electricity Spot Market

In January 2007, first evidence of an asymmetric pass-through of CO2 emission allowance prices was reported for the German electricity spot market. This paper explores the theoretical basis for such an asymmetry in the context of a supply function bidding duopoly. It interprets fluctuating carbon prices as a coordination mechanism for tacitly colluding firms and studies incentive compatibility in the repeated game. It is new in its attempt to model asymmetric behaviour in a spot market without relevant frictions, and gives a reasoning why the asymmetry shows up for emission allowances only. The paper concludes with a theorem: that asymmetric price transmission is sustained up to a certain maximum level which might include the monopoly solution and that this mechanism is always preferred to non-cooperation. --Asymmetric price transmission,Electricity spot markets,Emission allowances