Master Thesis

PUBDB-2025-00528

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Identification of Charged Leptons in Jets at Future Higgs Factories

Reichenbach, L. (Corresponding author)Extern* ; List, J. (Thesis advisor)DESY* ; Garutti, E. (Thesis advisor)Extern*

2022
Hamburg

Abstract: The 2012 discovery of the 12 GeV Higgs boson at the LHC, and of no other particle since then, have brought a consensus to the particle physics community that an e+e- Higgs factory is the highest priority next collider. However, Higgs measurements suffer from the loss of undetected neutrino energy due to semi-leptonic decays (SLDs) in the most common decay mode H to b anti-b. Previous work has shown the possibility to reconstruct the missing neutrino if the corresponding lepton and its production vertex are found. Search algorithms for these leptons are already in use to improve b-jet identification.In this work, a novel BDT-based method to identify SLD electrons and muons has been developed. Furthermore, a particle identification (PID) method for electrons and muons from jets was also built.The new PID can identify electrons with an efficiency of 95% and a purity of 98% given that dE/dx information is available. For muons, 74% efficiency and 89% purity were reached. Combined with this new PID, the developed SLD ID method can identify SLD electrons and muons with an efficiency of 65% and a purity of 77%.

Note: Masterarbeit, University of Hamburg, 2022

---

Contributing Institute(s):

1. Technol. zukünft. Teilchenph. Experim. (FTX)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)

Experiment(s):

1. Facility (machine) ILC

---