Reconstruction and classification of tau lepton decays with ILD

Abstract

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image)

Tau lepton decays with up to two ......s in the final state - ......, ......, and ...... - are used to study the performance of the barrel region of the silicon-tungsten electromagnetic calorimeter (Si-W ECAL) of the International Large Detector (ILD) at the future ...... International Linear Collider. Correct reconstruction of the tau decay mode is crucial for constraining the spin state of tau lepton and measuring the Higgs boson CP state in ...... decays. We find that about 95 % of ......, and 90 % of ...... and ...... decays produced by the ...... process at an ...... beam energy of 125 GeV are correctly reconstructed. In a smaller ILD detector, with the inner Si-W ECAL radius reduced by about 20 %, these efficiencies are reduced by at most 2 %. The ...... mass resolution remains below 10 %. Since failures in tau lepton reconstruction are mainly due to photons, an increase of the ILD magnetic field from 3.5 to 4 T does not bring any significant improvement.