arXiv subjects

Wouter Verkerke

Publications and source records attributed to Wouter Verkerke.

5 recordsLinked to original sources

arXiv2022

Effective Lagrangian Morphing

With the LHC entering the precision era, focus on interpreting the measurements performed in an effective field theory holds key to testing the Standard Model. An effective field theory provides a well-defined theoretical formalism which extends the Standard Model by introduce new terms with free coefficients that can be measured with experimental data. Constructing models parametric in these new coefficients is achieved by virtue of combining predictions from Monte Carlo generators for different interactions. This paper builds upon earlier works and describes a state-of-the-art approach to build multidimensional parametric models for new physics using effective Lagrangians. Documentation and tutorials for an associated toolkit that have been contributed to the ROOT data analysis software framework is included.

physics.data-an↗

arXiv2019

Comparison of unfolding methods using RooFitUnfold

In this paper we describe RooFitUnfold, an extension of the RooFit statistical software package to treat unfolding problems, and which includes most of the unfolding methods that commonly used in particle physics. The package provides a common interface to these algorithms as well as common uniform methods to evaluate their performance in terms of bias, variance and coverage. In this paper we exploit this common interface of RooFitUnfold to compare the performance of unfolding with the Richardson-Lucy, Iterative Dynamically Stabilized, Tikhonov, Gaussian Process, Bin-by-bin and inversion methods on several example problems.

physics.data-an↗

arXiv2014

Interpolation between multi-dimensional histograms using a new non-linear moment morphing method

A prescription is presented for the interpolation between multi-dimensional distribution templates based on one or multiple model parameters. The technique uses a linear combination of templates, each created using fixed values of the model's parameters and transformed according to a specific procedure, to model a non-linear dependency on model parameters and the dependency between them. By construction the technique scales well with the number of input templates used, which is a useful feature in modern day particle physics, where a large number of templates is often required to model the impact of systematic uncertainties.

physics.data-an↗

arXiv2011

The RooStats Project

RooStats is a project to create advanced statistical tools required for the analysis of LHC data, with emphasis on discoveries, confidence intervals, and combined measurements. The idea is to provide the major statistical techniques as a set of C++ classes with coherent interfaces, so that can be used on arbitrary model and datasets in a common way. The classes are built on top of the RooFit package, which provides functionality for easily creating probability models, for analysis combinations and for digital publications of the results. We will present in detail the design and the implementation of the different statistical methods of RooStats. We will describe the various classes for interval estimation and for hypothesis test depending on different statistical techniques such as those based on the likelihood function, or on frequentists or bayesian statistics. These methods can be applied in complex problems, including cases with multiple parameters of interest and various nuisance parameters.

physics.data-an↗

arXiv2003

The RooFit toolkit for data modeling

RooFit is a library of C++ classes that facilitate data modeling in the ROOT environment. Mathematical concepts such as variables, (probability density) functions and integrals are represented as C++ objects. The package provides a flexible framework for building complex fit models through classes that mimic math operators, and is straightforward to extend. For all constructed models RooFit provides a concise yet powerful interface for fitting (binned and unbinned likelihood, chi^2), plotting and toy Monte Carlo generation as well as sophisticated tools to manage large scale projects. RooFit has matured into an industrial strength tool capable of running the BABAR experiment's most complicated fits and is now available to all users on SourceForge.

physics.data-an↗