Giving top quark effective operators a boost

We investigate the prospects to systematically improve generic effective field theory-based searches for new physics in the top sector during LHC run 2 as well as the high luminosity phase. In particular, we assess the benefits of high momentum transfer final states on top EFT-fit as a function of systematic uncertainties in comparison with sensitivity expected from fully-resolved analyses focusing on $t\bar t$ production. We find that constraints are typically driven by fully-resolved selections, while boosted top quarks can serve to break degeneracies in the global fit. This demystifies and clarifies the importance of high momentum transfer final states for global fits to new interactions in the top sector from direct measurements.Comment: Published versio

A global fit of top quark effective theory to data

In this paper we present a global fit of beyond the Standard Model (BSM) dimension six operators relevant to the top quark sector to currently available data. Experimental measurements include parton-level top-pair and single top production from the LHC and the Tevatron. Higher order QCD corrections are modelled using differential and global K-factors, and we use novel fast-fitting techniques developed in the context of Monte Carlo event generator tuning to perform the fit. This allows us to provide new, fully correlated and model-independent bounds on new physics effects in the top sector from the most current direct hadron-collider measurements in light of the involved theoretical and experimental systematics. As a by-product, our analysis constitutes a proof-of-principle that fast fitting of theory to data is possible in the top quark sector, and paves the way for a more detailed analysis including top quark decays, detector corrections and precision observables.Comment: Additional references and preprint code added. Minor error in generation of plots fixed, no conclusions affecte

Образовательное учреждение: проблемы правового регулирования организационно-правовой формы

The vertebrate stress response has been shown to suppress investment in reproductive and immune function and may also lead to a reduced investment in the production of secondary sexual traits. However, it has been difficult to model roles of stress in sexual selection due to the inconsistent results seen in empirical studies testing for the effect of stress on the expression of secondary sexual traits. We conducted a phylogenetically controlled meta-analysis of published associations between physiological correlates of stress and sexual signaling in vertebrates in order to identify any consistent patterns. Our analysis included signaling in both males and females, 4 stress measures, and 4 categories of sexually selected traits (vocalizations, traits that varied in size, traits that varied in coloration, and opposite-sex preference). Across 38 studies of 26 species, there was no significant relationship between physiological correlates of stress and the expression of sexual signals. Mean effect size, however, varied significantly across the 4 types of sexually selected trait. We propose development of a model that incorporates the nuanced effects of species ecology, trait type, ecological context, and the complex nature of the physiological stress response, on the expression of sexually selected traits

Toolkit for photonic integrated circuits based on inverted rib waveguides

This work was supported by an EPSRC Doctoral Prize and a European Research Council Starting under Grant 337508.We have performed an exploration of inverted rib waveguide platform for use in optical backplanes. This entailed the design, optimization, and characterization of a variety of passive optical components that may serve as a basis for the functions required of an on-chip optical networks. The presented design introduces an inverted-rib template, which consists of a polymer waveguide layer. We have successfully fabricated and demonstrated low-loss waveguides, and also functional passive devices such as directional couplers, multimode interferometers, waveguide bends and crossings, and distributed Bragg reflectors. We also demonstrate a way of coupling active components (e.g., in silicon) to such a photonic integrated circuit.PostprintPeer reviewe

Top quark physics in the standard model effective field theory

We explore some applications of the Standard Model (SM) Effective Field Theory (EFT) as a tool with which to describe generic nonresonant new physics (NP) at hadron colliders. A global fit of the dimension-six Wilson Coefficients relevant to top quark production is presented, utilizing diverse experimental datasets from both the Large Hadron Collider (LHC) Runs I and II and the TeVatron, with current results in good agreement with the SM. Machinery is developed to systematically treat redundancies between higher-dimensional operators in the automated model-building and phenomenology toolkit FeynRules, and a general SMEFT model implementation for event generators detailed. We then investigate the importance of high momentum transfer final states in top pair production to the EFT fit, taking advantage of boosted reconstruction techniques. We find sensitivity is typically driven by fully resolved analyses in several benchmark scenarios for total integrated luminosity and experimental systematic uncertainties

Results from TopFitter

We discuss a global fit of top quark BSM couplings, phrased in the model-independent language of higher-dimensional effective operators, to the currently available data from the LHC and Tevatron. We examine the interplay between inclusive and differential measurements, and the complementarity of LHC and Tevatron results. We conclude with a discussion of projections for improvement over LHC Run II.Comment: 5 pages, 4 figures, proceedings of the 9th International Workshop on the CKM Unitarity Triangle, 28 November - 3 December 2016, Tata Institute for Fundamental Research (TIFR), Mumbai, Indi

Prognostic variables and scores identifying the end of life in COPD: a systematic review.

INTRODUCTION: COPD is a major cause of mortality, and the unpredictable trajectory of the disease can bring challenges to end-of-life care. We aimed to investigate known prognostic variables and scores that predict prognosis in COPD in a systematic literature review, specifically including variables that contribute to risk assessment of patients for death within 12 months. METHODS: We conducted a systematic review on prognostic variables, multivariate score or models for COPD. Ovid MEDLINE, EMBASE, the Cochrane database, Cochrane CENTRAL, DARE and CINAHL were searched up to May 1, 2016. RESULTS: A total of 5,276 abstracts were screened, leading to 516 full-text reviews, and 10 met the inclusion criteria. No multivariable indices were developed with the specific aim of predicting all-cause mortality in stable COPD within 12 months. Only nine indices were identified from four studies, which had been validated for this time period. Tools developed using expert knowledge were also identified, including the Gold Standards Framework Prognostic Indicator Guidance, the RADboud Indicators of Palliative Care Needs, the Supportive and Palliative Care Indicators Tool and the Necesidades Paliativas program tool. CONCLUSION: A number of variables contributing to the prediction of all-cause mortality in COPD were identified. However, there are very few studies that are designed to assess, or report, the prediction of mortality at or less than 12 months. The quality of evidence remains low, such that no single variable or multivariable score can currently be recommended

Methods for enhancing the reproducibility of biomedical research findings using electronic health records.

BACKGROUND: The ability of external investigators to reproduce published scientific findings is critical for the evaluation and validation of biomedical research by the wider community. However, a substantial proportion of health research using electronic health records (EHR), data collected and generated during clinical care, is potentially not reproducible mainly due to the fact that the implementation details of most data preprocessing, cleaning, phenotyping and analysis approaches are not systematically made available or shared. With the complexity, volume and variety of electronic health record data sources made available for research steadily increasing, it is critical to ensure that scientific findings from EHR data are reproducible and replicable by researchers. Reporting guidelines, such as RECORD and STROBE, have set a solid foundation by recommending a series of items for researchers to include in their research outputs. Researchers however often lack the technical tools and methodological approaches to actuate such recommendations in an efficient and sustainable manner. RESULTS: In this paper, we review and propose a series of methods and tools utilized in adjunct scientific disciplines that can be used to enhance the reproducibility of research using electronic health records and enable researchers to report analytical approaches in a transparent manner. Specifically, we discuss the adoption of scientific software engineering principles and best-practices such as test-driven development, source code revision control systems, literate programming and the standardization and re-use of common data management and analytical approaches. CONCLUSION: The adoption of such approaches will enable scientists to systematically document and share EHR analytical workflows and increase the reproducibility of biomedical research using such complex data sources