Latest results on differential cross sections as a function of kinematic variables at the LHC and Tevatron

An overview of recent measurements of differential top quark pair ($t\bar{t}$) production cross sections is presented, including results in boosted topologies and results both at parton and particle level. The first measurements of differential single top quark t-channel production cross sections in proton-proton collisions are as well presented. The results are obtained using data collected with the ATLAS and CMS experiments in proton-proton collisions at centre-of-mass energies of 7 TeV and 8 TeV. References to the latest results by the Tevatron experiments are also given. The data are compared with several predictions from perturbative QCD calculations up to approximate next-to-next-to-leading-order precision (approx. NNLO).Comment: 5 pages, 4 figures, TOP2014 Conferenc

ttˉ{\rm t\bar{t}} cross section measurements in CMS

An overview of the most recent measurements of inclusive top quark pair production cross section is presented. The results are obtained using data collected with the CMS experiment in proton-proton collisions at centre-of-mass energies of 5.02, 7, 8 and 13 TeV. The data are compared with the predictions from perturbative QCD calculations at full NNLO+NNLL accuracy.Comment: 6 pages, 5 figures, TOP2016 conferenc

Evidence for Widespread AGN Activity among Massive Quiescent Galaxies at z ~ 2

We quantify the presence of Active Galactic nuclei (AGN) in a mass-complete (M_* >5e10 M_sun) sample of 123 star-forming and quiescent galaxies at 1.5 < z < 2.5, using X-ray data from the 4 Ms Chandra Deep Field-South (CDF-S) survey. 41+/-7% of the galaxies are detected directly in X-rays, 22+/-5% with rest-frame 0.5-8 keV luminosities consistent with hosting luminous AGN (L_0.5-8keV > 3e42 ergs/s). The latter fraction is similar for star-forming and quiescent galaxies, and does not depend on galaxy stellar mass, suggesting that perhaps luminous AGN are triggered by external effects such as mergers. We detect significant mean X-ray signals in stacked images for both the individually non-detected star-forming and quiescent galaxies, with spectra consistent with star formation only and/or a low luminosity AGN in both cases. Comparing star formation rates inferred from the 2-10 keV luminosities to those from rest-frame IR+UV emission, we find evidence for an X-ray excess indicative of low-luminosity AGN. Among the quiescent galaxies, the excess suggests that as many as 70-100% of these contain low- or high-luminosity AGN, while the corresponding fraction is lower among star-forming galaxies (43-65%). The ubiquitous presence of AGN in massive, quiescent z ~ 2 galaxies that we find provides observational support for the importance of AGN in impeding star formation during galaxy evolution.Comment: 9 pages, 3 figures, 3 tables; Accepted for publication in ApJ. Minor editing changes and a few references added. Matches published versio

The political conditioning of subjective economic evaluations: the role of party discourse

Classic and revisionist perspectives on economic voting have thoroughly analyzed the role of macroeconomic indicators and individual partisanship as determinants of subjective evaluations of the national economy. Surprisingly, however, top-down analysis of parties’ capacity to cue and persuade voters about national economic conditions is absent in the debate. This study uses a novel dataset containing monthly economic salience in party parliamentary speeches, macroeconomic indicators and individual survey data covering the four last electoral cycles in Spain (1996–2011). The results show that the salience of economic issues in the challenger’s discourse substantially increases negative evaluations of performance when this challenger is the owner of the economic issue. While a challenger’s conditioning of public economic evaluations is independent of the state of the economy (and can affect citizens with different ideological orientations), incumbent parties are more constrained by the true state of the economy in their ability to persuade the electorate on this issue

Sin noticia de Castilla. Visiones contemporáneas de la España Moderna, 1926-1927 / 1953-1954

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