The NFLikelihood: An unsupervised DNNLikelihood from normalizing flows

SciPost Physics Core, vol. 7

Abstract

We propose the NFLikelihood, an unsupervised version, based on Normalizing Flows, of the DNNLikelihood proposed in [Eur. Phys. J. C 80, 664 (2020)]. We show, through realistic examples, how Autoregressive Flows, based on affine and rational quadratic spline bijectors, are able to learn complicated high-dimensional Likelihoods arising in High Energy Physics (HEP) analyses. We focus on a toy LHC analysis example already considered in the literature and on two Effective Field Theory fits of flavor and electroweak observables, whose samples have been obtained through the HEPFit code. We discuss advantages and disadvantages of the unsupervised approach with respect to the supervised one and discuss a possible interplay between the two.

Authors 2

1. Humberto Reyes-González Aachen

   RWTH Aachen University · University of Genoa · Istituto Nazionale di Fisica Nucleare, Sezione di Genova

   Affiliation as printed

   National Institute of Nuclear Physics Genoa Section

   RWTH Aachen University

   University of Genoa

   Department of Physics, University of Genova, Via Dodecaneso 33, 16146 Genova, Italy

   INFN, Sezione di Genova, Via Dodecaneso 33, I-16146 Genova, Italy

2. Riccardo Torre

   Istituto Nazionale di Fisica Nucleare, Sezione di Genova

   Affiliation as printed

   National Institute of Nuclear Physics Genoa Section

   INFN, Sezione di Genova, Via Dodecaneso 33, I-16146 Genova, Italy