An Examination of Long-Term Working Memory Capacity

The purpose of this research was to explore experts’ memory capacity and the strategies experts use to achieve that capacity. Expert air traffic controllers were asked to recall traffic information during two radar and two nonradar scenarios. During radar scenarios, air traffic information was communicated aurally and displayed visually. During nonradar scenarios, air traffic information was communicated aurally only. Qualitative recall data assessment revealed an average capacity of five to eight aircraft in radar scenarios and three to six in nonradar scenarios, with two to three details recalled for most recalled aircraft. Recalled details and order of detail recall were highly consistent across experts, which suggest that aircraft details were organized and stored within larger conceptual knowledge structures. Recall patterns were additionally suggestive of frames containing slots designated for holding specific data types, structures described by Klein’s Data/Frame Model of Sensemaking. The extent of information recalled and its organization are additionally consistent with the use of long term working memory to extend working memory capacity; however, they do not rule out the use of working memory alone. Differences between radar and nonradar conditions were observed. Greater overall recall and greater and earlier recall of certain data-tag elements were observed in radar scenarios. In nonradar scenarios, greater and earlier recall of assigned actions were observed. Evaluation of experts’ descriptions of their recall processes suggested primarily visuospatial information encoding in both conditions and a lack of support for differences in the use of visuospatial or verbal encoding

Measurement of isolated-photon pair production in pp collisions at √s=7 TeV with the ATLAS detector

The ATLAS experiment at the LHC has measured the production cross section of events with two isolated photons in the final state, in proton-proton collisions at s√=7TeV . The full data set collected in 2011, corresponding to an integrated luminosity of 4.9 fb−1, is used. The amount of background, from hadronic jets and isolated electrons, is estimated with data-driven techniques and subtracted. The total cross section, for two isolated photons with transverse energies above 25 GeV and 22 GeV respectively, in the acceptance of the electromagnetic calorimeter (|η|  0.4, is 44.0+3.2−4.2 pb. The differential cross sections as a function of the di-photon invariant mass, transverse momentum, azimuthal separation, and cosine of the polar angle of the largest transverse energy photon in the Collins-Soper di-photon rest frame are also measured. The results are compared to the prediction of leading-order parton-shower and next-to-leading-order and next-to-next-to-leading-order parton-level generators

Search for high-mass resonances decaying to dilepton final states in pppp collisions at s=7\sqrt{s}= 7 TeV with the ATLAS detector

The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to an electron-positron pair or a muon-antimuon pair. The search is sensitive to heavy neutral Z' gauge bosons, Randall-Sundrum gravitons, Z* bosons, techni-mesons, Kaluza-Klein Z/gamma bosons, and bosons predicted by Torsion models. Results are presented based on an analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.9/fb in the dielectron channel and 5.0/fb in the dimuon channel. A Z' boson with Standard Model-like couplings is excluded at 95 percent confidence level for masses below 2.22 TeV. A Randall-Sundrum graviton with coupling k/Mbar = 0.1 is excluded at 95 percent confidence level for masses below 2.16 TeV. Limits on the other models are also presented, including Technicolor and Minimal Z' Models.Comment: 31 pages plus author list (53 pages total), 10 figures, 16 tables, submitted to Journal of High Energy Physics Revision corresponds to published versio