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These proceedings present the method and performance of primary vertex reconstruction at the ATLAS experiment during Runs 1 and 2 at the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of s=8TeV, and during 2015-2016 at s=13TeV. Some predictions toward future runs are also presented. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed.

High heat flux and radio blackout are well-known challenges space vehicles have been facing during re-entry into a planet’s atmosphere since the early days of space-flight. Thermal protection systems have been developed to protect spacecraft and astronauts, however, they are often heavy and some have to be replaced after each mission. High temperatures in the compressed gas in the shock wave lead to partial ionization. The dense plasma can cause radio blackout, i.e. attenuation or reflection of radio waves thus blocking data-telemetry and communication with ground stations or satellites. One approach to solve both problems is to influence the plasma with magnetohydrodynamic effects using a strong magnet. In the framework of the European project MEESST (Magnetohydrodynamic Enhanced Entry System for Space Transportation) heat flux mitigation and radio blackout mitigation is investigated by means of modelling and ground experiments in plasma wind tunnels at the Institute of Space Systems (Stuttgart, Germany) and at the Von Karman Institute for Fluid Dynamics (Brussels, Belgium) using an HTS magnet. After a short introduction to the scientific background of the MEESST project, the boundary conditions for the design of the magnet and calculations of field distributions are presented. The pancake coils of the magnet were wound with a robotic winding system. Results from a preliminary test of the conduction-cooled magnet are presented.

The reconstruction of vertices corresponding to proton-proton collisions in ATLAS is an essential element of event reconstruction used in many performance studies and physics analyses. During Run-1 of the LHC, ATLAS has employed an iterative approach to vertex finding. In order to improve the flexibility of the algorithm and ensure continued performance for very high numbers of simultaneous collisions in Run-2 of the LHC and beyond, a new approach to seeding vertex finding has been developed inspired by image reconstruction techniques. This note provides a brief outline of how reconstructed tracks are used to create an image of likely vertex collisions in an event, describes the implementation in the ATLAS software, and presents some preliminary results of the performance of the algorithm in simulation approximating early Run-2 conditions.

Large international collaborations that use decentralized computing models are becoming a custom rather than an exception in High Energy Physics. A good computing model for such big collaborations has to deal with the distribution of the experiment-specific software around the world. When the CDF experiment developed its software infrastructure, most computing was done on dedicated clusters. As a result, libraries, configuration files and large executables were deployed over a shared file system. In order to adapt its computing model to the Grid, CDF decided to distribute its software to all European Grid sites using Parrot, a user-level application capable of attaching existing programs to remote I/O systems through the filesystem interface. This choice allows CDF to use just one centralized source of code and a scalable set of caches all around Europe to efficiently distribute its code and requires almost no interaction with the existing Grid middleware or with local system administrators. This system has been in production at CDF in Europe since almost two years. Here, we present CDF implementation of Parrot and some comments on its performances.

A preliminary thermal 1D numerical model for studying the demise behavior of stainless steel 316L, silicon carbide (SiC) and carbon fiber reinforced polymer (CFRP) during uncontrolled atmospheric entry is proposed. Test case modeling results are compared to experimental data obtained in the framework of ESA Clean Space initiative: material samples were exposed to different heat flux conditions using the Plasma Wind Tunnel (PWT) facilities at the Institute of Space Systems (IRS) of the University of Stuttgart. This numerical model approximates the heating history of the selected materials by simulating their thermal response and temperature profiles, which have trends similar to the experimental curves that are found. Moreover, when high heat flux conditions are considered, the model simulates the materials’ mass loss due to the ablation process: at the end of the simulation, the difference between the experimental and the modeled results is about 17% for CFRP and 35% for stainless steel. To reduce the model’s uncertainties, the following analysis suggests the need to consider the influence of adequate material thermophysical properties and the physical-chemical processes that affect the samples’ temperature profile and mass loss.

Presented in this contribution are methods currently developed and used by the ATLAS collaboration to measure the performance of the primary vertex reconstruction algorithms. With the increasing instantaneous luminosity at the LHC, many proton-proton collisions occur simultaneously in one bunch crossing. The correct identification of the primary vertex from a hard scattering process and the knowledge of the number of additional pile-up interactions is crucial for many physics analyses. Under high pile-up conditions, additional effects like splitting one vertex into many or reconstructing several interactions as one also become sizable effects. The mathematical methods, their software implementation, and studies presented in this contribution are methods currently developed and used by the ATLAS collaboration to measure the performance of the primary vertex reconstruction algorithms. Statistical methods based on data and Monte Carlo simulation are both used to disentangle and understand the different contributions.

Evangelicals arguably constitute an unexpected base of support for Donald Trump. One plausible account holds that evangelicals supported Trump reluctantly, backing him not because they strongly favored him, but rather because they viewed him as the least objectionable candidate. This perspective suggests a possible enthusiasm gap: among Donald Trump's supporters, nonevangelicals were more zealous while evangelicals were more tepid. We examine this account using data from March 2019, just past the midpoint of Trump's presidency, a period when any lack of enthusiasm with Trump among portions of his base should have been discernible. Our expansive analytical strategy, using OLS and matching, explores whether evangelicals offered Donald Trump more lukewarm support than did nonevangelicals, with support operationalized in six ways. Across 36 tests, no evidence of an enthusiasm gap between evangelicals and nonevangelicals is detected. Seen both in absolute terms and relative to nonevangelicals, evangelicals offered Donald Trump fervent support.

The comic anthology Ricanstruction: Reminiscing & Rebuilding Puerto Rico engages its Afro-Latina superhero in recovery efforts after Hurricane Maria. This study uses a linguistic critical framework and Critical Discourse Analysis to determine how the anthology presents women and Puerto Ricans. Although it champions women and Puerto Rican agency, language and communication strategies in the collection reveal complexities and contradictions such as the reliance of both the central female superhero and Puerto Rican islanders on external--specifically US--assistance and collaboration, implying unity among islanders and the diaspora but also suggesting dependency in ways that index discourses of female and colonial subordination. In addition, representations of rural Puerto Rico are prone to literary romanticization but also expose actual paradigms of socio-economic discrimination. The predominant use of English in the anthology, with Spanish for emphasis, highlights speech practices of the US diaspora, yet the cyclical re-interpretations of discourse structures reference Caribbean rhythms. [Keywords: critical discourse analysis, superhero comics, colonial dependency, diaspora, female agency, environmental discrimination]