Theory and Applications of Robust Optimization

In this paper we survey the primary research, both theoretical and applied, in the area of Robust Optimization (RO). Our focus is on the computational attractiveness of RO approaches, as well as the modeling power and broad applicability of the methodology. In addition to surveying prominent theoretical results of RO, we also present some recent results linking RO to adaptable models for multi-stage decision-making problems. Finally, we highlight applications of RO across a wide spectrum of domains, including finance, statistics, learning, and various areas of engineering.Comment: 50 page

The Fate of Long-Lived Superparticles with Hadronic Decays after LHC Run 1

Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation, and mini-split SUSY. We explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final-state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMS's tracker-based displaced dijet search and heavy stable charged particle searches. Adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.Comment: 36 pages, 10 figures, plus appendix and reference

Top Quark Physics at the Tevatron

We review the field of top-quark physics with an emphasis on experimental techniques. The role of the top quark in the Standard Model of particle physics is summarized and the basic phenomenology of top-quark production and decay is introduced. We discuss how contributions from physics beyond the Standard Model could affect top-quark properties or event samples. The many measurements made at the Fermilab Tevatron, which test the Standard Model predictions or probe for direct evidence of new physics using the top-quark event samples, are reviewed here.Comment: 50 pages, 17 figures, 2 tables; version accepted by Review of Modern Physic

Object Classification in Astronomical Multi-Color Surveys

We present a photometric method for identifying stars, galaxies and quasars in multi-color surveys, which uses a library of >65000 color templates. The method aims for extracting the information content of object colors in a statistically correct way and performs a classification as well as a redshift estimation for galaxies and quasars in a unified approach. For the redshift estimation, we use an advanced version of the MEV estimator which determines the redshift error from the redshift dependent probability density function. The method was originally developed for the CADIS survey, where we checked its performance by spectroscopy. The method provides high reliability (6 errors among 151 objects with R<24), especially for quasar selection, and redshifts accurate within sigma ~ 0.03 for galaxies and sigma ~ 0.1 for quasars. We compare a few model surveys using the same telescope time but different sets of broad-band and medium-band filters. Their performance is investigated by Monte-Carlo simulations as well as by analytic evaluation in terms of classification and redshift estimation. In practice, medium-band surveys show superior performance. Finally, we discuss the relevance of color calibration and derive important conclusions for the issues of library design and choice of filters. The calibration accuracy poses strong constraints on an accurate classification, and is most critical for surveys with few, broad and deeply exposed filters, but less severe for many, narrow and less deep filters.Comment: 21 pages including 10 figures. Accepted for publication in Astronomy & Astrophysic

Scintillation Pulse Shape Discrimination in a Two-Phase Xenon Time Projection Chamber

The energy and electric field dependence of pulse shape discrimination in liquid xenon have been measured in a 10 gm two-phase xenon time projection chamber. We have demonstrated the use of the pulse shape and charge-to-light ratio simultaneously to obtain a leakage below that achievable by either discriminant alone. A Monte Carlo is used to show that the dominant fluctuation in the pulse shape quantity is statistical in nature, and project the performance of these techniques in larger detectors. Although the performance is generally weak at low energies relevant to elastic WIMP recoil searches, the pulse shape can be used in probing for higher energy inelastic WIMP recoils.Comment: 7 pages, 11 figure

Experimental Tests of the Standard Model

Four lectures on experimental test of the standard model presented at the Advanced Summer Institute on Techniques and Concepts of High Energy Physics.Comment: 46 page LaTeX with 35 figures included using epsf, requires crckapb.sty. For publication in Proceedings of the NATO Advanced Study Institute on Techniques and Concepts of High Energy Physics (1998: St. Croix, V. I.) Ed. T. Ferbe

Development of Measures to Assess Dimensions of IS Operation Transactions

Information Systems (IS) researchers often rely on organizational economics models to describe and explain various IS management issues. While those models are found to be useful, measures are yet to be proposed to assess the dimensions of IS transactions. In this paper, we present the results of a study that was a first effort toward this end. The focus of the study was on one type of transaction, IS operations, in a particular management context, that of outsouring. Measures were developed for four critical dimensions of IS operation transactions: asset specificity, measurement problem, origin of the most important investment, and governance mechanism. Data from 250 large Canadian firms were used to assess the measures, using the Partial Least Squares (PLS) technique. L'économie des organisations est souvent mise à contribution par les chercheurs en systèmes d'information (SI). Peu de travaux ont cependant proposé des instruments de mesure des dimensions transactionnelles des opérations de SI. Ce mémoire marque un pas dans cette direction. Nous proposons des instruments de mesure utiles à l'analyse de l'impartition des opérations informatiques. Quatre dimensions importantes des transactions informatiques retiennent notre attention : la spécificité des actifs, les problèmes de mesure, l'origine des investissements les plus importants et le mode de régie des transactions. Une analyse de moindres carrés partiels (Partial Least Squares) est effectuée à l'aide de données provenant de 250 grandes entreprises canadiennes.Organizational economics; Outsourcing, Économie des organisations ; Impartition ; Sous-traitance

Direct measurement of the top-quark decay width with the ATLAS detector

The top quark is the heaviest known elementary particle. Due to its large mass, the top quark decays before it forms bound states. This makes the top quark a unique particle in the Standard Model. Precise measurements of its properties could be used as tests of the consistency of the Standard Model and potential deviations could point to physics Beyond the Standard Model. This thesis deals with the direct measurement of the top-quark decay width using data collected in proton-proton collisions at centre-of-mass energies of 8 and $13$ TeV with the ATLAS detector at the Large Hadron Collider. The thesis focuses on the more recent measurement at $13$ TeV while the most important highlights of the $8$ TeV measurement are summarised. The decay width of the top quark is extracted from the data using a likelihood fit of distributions of variables sensitive to the top-quark decay width in $t\bar{t}$ pair production. The measurement is performed in a direct way, thus it is less model-dependent compared to indirect methods