18,292 research outputs found
Charm and Beauty Photoproduction at HERA
After the completion of data taking at HERA-2, a large data set is at hand to
study the photoproduction of charm and beauty quarks in ep collisions. New
measurements of charm production based on D^* meson tagging and beauty
production based on muon and electron reconstruction test perturbative QCD
calculations with improved accuracy. In general, QCD calculations at NLO
describe the data well. The scale uncertainties are, however, large and
dominate over the experimental uncertainties, calling for more precise
calculations.Comment: Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 4 pages,
LaTeX, 3 eps figure
The ILC Potential for Discovering New Particles
The LHC did not discover new particles beyond the Standard Model Higgs boson
at 7 and 8 TeV, or in the first data samples at 13 TeV. However, the
complementary nature of physics with collisions still offers many
interesting scenarios in which new particles can be discovered at the ILC.
These scenarios take advantage of the capability of collisions to
observe particles with missing energy and small mass differences, to observe
mono-photon events with precisely controlled backgrounds, and to observe the
full range of exotic decay modes of the Higgs boson. The searches that an
collider makes possible are particularly important for models of dark
matter involving a dark sector with particles above the modest energy reach of
fixed-target experiments. In this talk, we will review the opportunities that
the ILC offers for new particle discovery.Comment: on behalf of the LCC Physics W
Complex Collective Decisions and the Probability of Collective Inconsistencies
Many groups are required to make collective decisions over multiple interconnected propositions. The "doctrinal paradox" or "discursive dilemma" shows that propostionwise majority voting can lead to inconsistent collective outcomes, even when the judgments of individual group members are consistent. How likely is the occurence of this paradox? This paper develops a simple model for determining the probability of the paradox's occurrence, given various assumptions about the probability of different individual judgments. Several convergence results will be proved, identifying conditions under which the probability of the paradox's occurrence converges to certainty as the number of individuals increases, and conditions under which that probability vanishes. The present model will also be used for assessing the "truth-tracking" performance of two escape-routes from the paradox, the premise- and conclusion-based procedures. Finally, the results on the probability of the doctrinal paradox will be compared with existing results on the probability of Condorcet's paradox of cyclical preferences. It will be suggested that the doctrinal paradox is more likely to occur than Condorcet's paradox.
Distributional National Accounts (DINA) for Austria, 2004-2016
This paper constructs distributional national accounts for Austria for the period 2004-2016. We enrich survey data with tabulated tax data and make it fully consistent with national accounts data. The comprehensive dataset allows us to analyse the distribution of macroeconomic growth across the income distribution and to explore the evolution of income inequality in pre-tax income over time. Our results suggest that the distribution of growth has changed over time, which had considerable repercussions on inequality. Inequality started to decline at the very beginning of the economic and financial crisis in 2007, however it has increased again after 2012. We further provide novel insights into the evolution of capital income for top income groups and explore redistribution mechanisms that operated in Austria. Government spending was found to play a key role for redistributive effects across the income distribution. In particular, the transfer system redistributes pre-tax income to a large extent.Series: INEQ Working Paper Serie
Group deliberation and the transformation ofjudgments: an impossibility result
While a large social-choice-theoretic literature discusses the aggregation ofindividual judgments into collective ones, there is relatively little formalwork on the transformation of individual judgments in group deliberation. Idevelop a model of judgment transformation and prove a baselineimpossibility result: Any judgment transformation function satisfying someinitially plausible condition is the identity function, under which no opinionchange occurs. I identify escape routes from this impossibility result andargue that successful group deliberation must be 'holistic': individualscannot generally revise their judgments on a proposition based on judgmentson that proposition alone but must take other propositions into account too. Idiscuss the significance of these findings for democratic theory.group deliberation, judgment aggregation, judgmenttransformation, belief revision
Polarimetry at the ILC
At the ILC, the luminosity-weighted average polarization at the IP needs to
be determined at the permille-level. In order to reach this goal, the combined
information from the polarimeter and the collision data is required. In this
study, a unified approach will be presented, which for the first time combines
the cross section measurements with the expected constraints from the
polarimeters. Hereby, the statistical and systematical uncertainties are taken
into account, including their correlations. This study shows that a fast spin
flip frequency is required because it easily reduces the systematic
uncertainty, while a non-perfect helicity reversal can be compensated for
within the unified approach. The final goal is to provide a realistic
estimation of the luminosity-weighted average polarization at the IP to be used
in the physic analyses.Comment: 8 pages, conference proceedings LCWS 2016 Morioka Japa
What is special about the proportion? A research report on special majority voting and the classical Condorcet jury theorem
It is known that, in Condorcetâs classical model of jury decisions, the proportion of jurors supporting a decision is not a significant indicator of that decisionâs reliability: the probability that a particular majority decision is correct given the size of the majority depends only on the absolute margin between the majority and the minority, and is invariant under changes of the proportion in the majority if the absolute margin is held fixed. Here I show that, if we relax the assumption that juror competence is independent of the juryâs size, the proportion can be made significant: there are then conditions in which the probability that a given majority decision is correct depends only on the proportion of jurors supporting that decision, and is invariant under changes of the jury size. The proportion is significant in this way if and only if juror competence is a particular decreasing function of the jury size. However, the required condition on juror competence is not only highly special â thereby casting doubt on the significance of the proportion in realistic conditions â but it also has an adverse implication for the Condorcet jury theorem. If the proportion is significant, then the Condorcet jury theorem fails to hold; and if the Condorcet jury theorem holds, the proportion is not significant. I discuss the implications of these results for defining and justifying special majority voting from the perspective of an epistemic account of voting.Condorcet jury theorem, special majority voting, proportion, decreasing juror competence
The Methodology of Political Theory
This article examines the methodology of a core branch of contemporary political theory or philosophy: âanalyticâ political theory. After distinguishing political theory from related fields, such as political science, moral philosophy, and legal theory, the article discusses the analysis of political concepts. It then turns to the notions of principles and theories, as distinct from concepts, and reviews the methods of assessing such principles and theories, for the purpose of justifying or criticizing them. Finally, it looks at a recent debate on how abstract and idealized political theory should be, and assesses the significance of disagreement in political theory. The discussion is carried out from an angle inspired by the philosophy of science
What Normative Facts Should Political Theory Be About? Philosophy of Science meets Political Liberalism
Just as different sciences deal with different factsâsay, physics versus biologyâso we may
ask a similar question about normative theories. Is normative political theory concerned
with the same normative facts as moral theory or different ones? By developing an analogy
with the sciences, we argue that the normative facts of political theory belong to a higherâ
more coarse-grainedâlevel than those of moral theory. The latter are multiply realizable by
the former: competing facts at the moral level can underpin the same facts at the political
one. Consequently, some questions that moral theories answer are indeterminate at the
political level. This proposal offers a novel interpretation of John Rawlsâs idea that, in public
reasoning, we should abstract away from comprehensive moral doctrines. We contrast our
distinction between facts at different levels with the distinction between admissible and
inadmissible evidence and discuss some implications for the practice of political theory
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