Recombination Algorithms and Jet Substructure: Pruning as a Tool for Heavy Particle Searches

We discuss jet substructure in recombination algorithms for QCD jets and single jets from heavy particle decays. We demonstrate that the jet algorithm can introduce significant systematic effects into the substructure. By characterizing these systematic effects and the substructure from QCD, splash-in, and heavy particle decays, we identify a technique, pruning, to better identify heavy particle decays into single jets and distinguish them from QCD jets. Pruning removes protojets typical of soft, wide angle radiation, improves the mass resolution of jets reconstructing a heavy particle decay, and decreases the QCD background. We show that pruning provides significant improvements over unpruned jets in identifying top quarks and W bosons and separating them from a QCD background, and may be useful in a search for heavy particles.Comment: 33 pages, 42 figure

The NASA MSFC Electrostatic Levitation (ESL) Laboratory: Summary of Capabilities, Recent Upgrades, and Future Work

The NASA Marshall Space Flight Center (MSFC) electrostatic levitation (ESL) laboratory has a long history of providing materials research and thermophysical property data. A summary of the labs capabilities, recent upgrades, and ongoing and future work will be provided. The laboratory has recently added two new capabilities to its main levitation chamber: a rapid quench system and an oxygen control system. The rapid quench system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy. Thereby allowing rapid quenching of undercooled liquid metals. The oxygen control system consists of an oxygen sensor, oxygen pump, and a control unit. The sensor is a potentiometric device that determines the difference in oxygen activity between two gas compartments separated by an electrolyte, which is yttria-stabilized zirconia. The pump utilizes coulometric titration to either add or remove oxygen. The system is controlled by a desktop control unit, which can also be accessed via a computer. This system allows the oxygen partial pressure within the vacuum chamber to be measured and controlled, theoretically in the range from 10-36 to 100 bar. The ESL laboratory also has an emissometer, called the High-Temperature Emissivity Measurement System (HiTEMS). This system measures the spectral emissivity of materials from 600degC to 3,000degC. The system consists of a vacuum chamber, a black body source, and a Fourier Transform Infrared Spectrometer (FTIR). The system utilizes optics to swap the signal between the sample and the black body. The system was originally designed to measure the hemispherical spectral emissivity of levitated samples, which are typically 2.5mm spheres. Levitation allows emissivity measurements of molten samples, but more work is required to develop this capability. The system is currently setup measure the near-normal spectral emissivity of stationary samples, which has been used to take measurements of ablative materials, rocket nozzle coating materials, and materials for spacecraft instruments

XCone: N-jettiness as an exclusive cone jet algorithm

We introduce a new jet algorithm called XCone, for eXclusive Cone, which is based on minimizing the event shape N -jettiness. Because N -jettiness partitions every event into N jet regions and a beam region, XCone is an exclusive jet algorithm that always returns a fixed number of jets. We use a new “conical geometric” measure for which well-separated jets are bounded by circles of radius R in the rapidity-azimuth plane, while overlapping jet regions automatically form nearest-neighbor “clover jets”. This avoids the split/merge criteria needed in inclusive cone algorithms. A key feature of XCone is that it smoothly transitions between the resolved regime where the N signal jets of interest are well separated and the boosted regime where they overlap. The returned value of N -jettiness also provides a quality criterion of how N -jet-like the event looks. We also discuss the N -jettiness factorization theorems that occur for various jet measures, which can be used to compute the associated exclusive N -jet cross sections. In a companion paper [1], the physics potential of XCone is demonstrated using the examples of dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs.United States. Department of Energy (Offices of Nuclear and Particle Physics Contracts DE-SC00012567 and DE-SC0011090)Simons Foundation (Investigator grant 327942)United States. Department of Energy (Early Career research program DE-SC0006389)Alfred P. Sloan Foundation (Sloan Research Fellowship)Massachusetts Institute of Technology. Undergraduate Research Opportunities Program (Paul E. Gray Endowed Fund

Echocardiographic evaluation of atrioventricular orifice anatomy in children with atrioventricular septal defect

AbstractIn atrioventricular (AV) septal defect, the common AV valve can have a common orifice or can be divided by bridging leaflet tissue into two separate orifices. To determine the accuracy of a two-dimensional echocardiographic technique devised specifically for evaluation of the number of AV valve orifices, all 69 children undergoing surgical repair of AV septal defect from April 1987 to August 1999 were examined prospectively. The presence of bridging leaflet tissue and the number of AV valve orifices were determined with use of a subcostal imaging plane. From a standard subcostal four-chamber view, the plane of sound was rotated 30 ° to 45 ° clockwise until the AV valve was seen en face. The plane of sound was then tilted from a superior to an inferior direction so that cross-sectional views of the AV valve were examined from the inferior margin of the atrial septum to the superior margin of the ventricular septum.Of the 69 patients, 6 (9%) were excluded because the appropriate subcostal images were not obtained (in 3 because of obesity and in 3 as a result of operator failure). The remaining 63 children, ranging in age from 1 day to 13.5 years and in weight from 1 to 55 kg, constituted the study group. Echocardiographic results were compared with surgical observations in 62 patients and with autopsy findings in 1 patient.With the two-dimensional echocardiographic technique, 32 of 33 patients with a common orifice and 28 of 30 patients with two separate AV valve orifices were correctly identified. By chi-square analysis, the echocardiographic technique allowed correct identification of a common orifice valve with 94% sensitivity and 97% specificity. For correct identification of two separate orifices, the echocardiographic technique had 97% sensitivity and 94% specificity. The positive predictive value of the echocardiographic technique was 97% for a common orifices and 93% for two separate orifices. Thus, in patients with AV septal defect, the presence of bridging leaflet tissue and the number of AV valve orifices can be accurately determined with use of a subcostal two-dimensional imaging plane

Forest Glen Savanna

Print out of the Prairies/Native Plants page from the Vermilion County Conservation District website. Printed 8/10/2016

Forest Glen Savanna

Print out of the Prairies/Native Plants page from the Vermilion County Conservation District website. Printed 8/10/2016

The Dialectics of Ambivalent Identification in the Supervisor-Subordinate Dyad

Ambivalent interpersonal relationships in organizations are known to have deleterious effects on employee health and wellbeing, work performance, counterproductive work behaviors, and more. However, little research has examined ambivalent relationships in the supervisor-subordinate dyad. In the present study, I contribute to the supervisor-subordinate literature by examining the interaction between abusive supervision and supervisor support. Furthermore, I extend past findings by investigating the mediating role of ambivalent supervisor identification, hypothesizing that support in an otherwise abusive supervisor relationship will lead to ambivalent supervisor identification and, consequently, negative health outcomes. Finally, I explore the role of dialectical thinking style, an Eastern mode of thinking which allows for the acceptance of contradiction, as a moderating factor between ambivalent supervisor behaviors and ambivalent supervisor identification. The data for this thesis came from an archival dataset in which my variables of interest were included. My findings failed to replicate past research on the direct, interactive effects of abusive supervision and supervisor support. However, there was a significant indirect effect of this interaction through ambivalent supervisor identification predicting stress but not wellbeing. I found no significant effect for the contradiction dimension of dialectical thinking style, which may be due to sampling and survey restrictions. Limitations, future directions, and practical implications are discussed

Rise of Women

This zine walks through the history of women’s involvement in the summer olympic games. The timeline shows advancements in women’s rights and empowerment through athletics. The zine also explains how equality will further grow in the olympic games.https://digitalcommons.butler.edu/spring_2023/1000/thumbnail.jp