First Measurements of Spin Correlation Using Semi-leptonic ttˉt\bar{t} Events at ATLAS

The top quark decays before it hadronizes. Before its spin state can be changed in a process of strong interaction, it is directly transferred to the top quark decay products. The top quark spin can be deduced by studying angular distributions of the decay products. The Standard Model predicts the top/anti-top quark ($t\bar{t}$) pairs to have correlated spins. The degree is sensitive to the spin and the production mechanisms of the top quark. Measuring the spin correlation allows to test the predictions. New physics effects can be reflected in deviations from the prediction. The measurement of the spin correlation of $t\bar{t}$ pairs, produced at the LHC with a center-of-mass energy of $\sqrt{s} = 7$ TeV and reconstructed with the ATLAS detector, is presented. The dataset corresponds to an integrated luminosity of 4.6 $\textrm{fb}^{-1}$. $t\bar{t}$ pairs are reconstructed in the $\ell$+jets channel using a kinematic likelihood fit offering the identification of light up- and down-type quarks from the $t \rightarrow bW \rightarrow bq\bar{q}'$ decay. The spin correlation is measured via the distribution of the azimuthal angle $\Delta \phi$ between two top quark spin analyzers in the laboratory frame. It is expressed as the degree of $t\bar{t}$ spin correlation predicted by the Standard Model, $f_{\textrm{SM}}$. The result of $f_{\textrm{SM}}= 1.12 \pm 0.11\,\text{(stat.)} \pm 0.22\,\text{(syst.)}$ is consistent with the Standard Model prediction of $f_{\textrm{SM}}= 1.0$.Comment: 4 pages, 3 figures, to appear in the proceedings of Top2014, Cannes, France (28th Sept - 3rd Oct 2014

Financing the EU budget - Present situations and perspective

Ausgaben, Einnahmen, Finanzierung, Öffentlicher Haushalt, Europäische Wirtschafts- und Währungsunion, Expenditure, Revenue, Financing, Public Budget, European Economic and Monetary Union

Quasimolecular structure in elastic O16 + O16 scattering

It is suggested that the experimentally observed intermediate structure in the cross section of elastic O16 + O16 scattering is due to quasibound molecular states of the ion-ion system while the gross structure originates from virtually bound molecular states

INEFFICIENCIES OF INSTITUTIONAL ARRANGEMENTS IN INTERNATIONAL WHEAT TRADE A PRELIMINARY INVESTIGATION OF EASTERN EUROPE AND SOUTH AFRICA

The beginning of the new century marked important changes in the world wheat market. These changes relate to traditional wheat export countries. In future, non-traditional wheat export countries in Eastern Europe, such as the Ukraine, may increasingly put pressure on traditional wheat suppliers in the world market.International Relations/Trade,