25 years of the UK EIA System: Strengths, weaknesses, opportunities and threats

This paper offers a review of the UK EIA system, providing insights into its evolution and reflecting on perceptions of effectiveness of the EIA system. The work adopts a similar approach used by Glasson in 1999, where he provided a review of the first 10 years of EIA in the UK, complimented by a SWOT analysis. In conducting the SWOT analysis, the authors make use of (1) a UK EIA survey which was conducted in 2011; (2) an interactive session organised at a 2013 workshop at the University of Liverpool on 25 years of the EU EIA Directive; and (3) a systematic literature review of publications since 1999. The results indicate that the internal factors (i.e. strengths and weaknesses) of the EIA system have not actually changed much in the last 15 years. Changes are more apparent for the external factors, especially with regards to opportunities. However, EIA may be suffering from a mid-life crisis at this point and a lot may be owing to perceptions towards EIA which may be influenced and inversely related to the length of experience in EIA. This opens up avenues for further research in the area

Measurement of differential tt¯ production cross sections using top quarks at large transverse momenta in pp collisions at s=13 TeV

A measurement is reported of differential top quark pair (t¯t) production cross sections, where top quarks are produced at large transverse momenta. The data collected with the CMS detector at the LHC are from pp collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 35.9 fb − 1. The measurement uses events where at least one top quark decays as t→Wb→¯q′ b and is reconstructed as a large-radius jet with transverse momentum in excess of 400 GeV. The second top quark is required to decay either in a similar way or leptonically, as inferred from a reconstructed electron or muon, a bottom quark jet, and missing transverse momentum due to the undetected neutrino. The cross section is extracted as a function of kinematic variables of individual top quarks or of the t¯t system. The results are presented at the particle level, within a region of phase space close to that of the experimental acceptance, and at the parton level and are compared to various theoretical models. In both decay channels, the observed absolute cross sections are significantly lower than the predictions from theory, while the normalized differential measurements are well described