Abstrakt
The reconstruction of the Higgs boson mass represents one of the key challenges in the H->ττ analysis, where instant τ-lepton decays contain non-detectable neutrinos. Precise mass reconstruction is a prerequisite for reasonable separation between the signal (alike gg->H->ττ) and background (e.g.
Z->ττ) processes. The ATLAS collaboration has developed an advanced technique for the Higgs boson mass reconstruction (Missing Mass Calculator, MMC) which proved its efficiency and resolution in Run 1 and first Run 2 analyses at the LHC.
MMC relies on knowledge of the probability of the decay topology, the missing transverse energy (MET) is used as a proxy of neutrinos system momentum. For each event, mass is calculated over kinematically allowed phase space of the decay angles, and configuration with the highest probability is chosen as a final mass decision.
Recent efforts addressed MMC re-tuning to the updated reconstruction of the ATLAS core software Athena. A new, data-set independent, approach for MET resolution estimation based on MET significance has been introduced.
A faster scheme for the mass estimation is also suggested. These results as well as plans for further developments are presented.