Regular Article - Theoretical Physics
Tagging the Higgs boson decay to bottom quarks with colour-sensitive observables and the Lund jet plane
Dipartimento di Fisica, Università di Pavia, Via A. Bassi 6, 27100, Pavia, Italy
2 INFN, Sezione di Genova, Via Dodecaneso 33, 16146, Genova, Italy
3 H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, BS8 1TL, Bristol, UK
4 Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146, Genova, Italy
5 INFN, Sezione di Pavia, Universita di Pavia, Via A. Bassi 6, 27100, Pavia, Italy
6 Physik-Institut, Universität Zürich, Wintherturerstrasse 190, 8057, Zurich, Switzerland
Accepted: 17 May 2022
Published online: 28 May 2022
We study the problem of distinguishing b-jets stemming from the decay of a colour singlet, such as the Higgs boson, from those originating from the abundant QCD background. In particular, as a case study, we focus on associate production of a vector boson and a Higgs boson decaying into a pair of b-jets, which has been recently observed at the LHC. We consider the combination of several theory-driven observables proposed in the literature, together with Lund jet plane images, in order to design an original Hbb tagger. The observables are combined by means of standard machine learning algorithms, which are trained on events obtained with fast detector simulation techniques. We find that the combination of high-level single-variable observables with the Lund jet plane provides an excellent discrimination performance. We also study the dependence of the tagger on the invariant mass of the decaying particles, in order to assess the extension to a generic Xbb tagger.
© The Author(s) 2022
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3