Conceptual aspects for the improvement of the reconstruction of $b$- and $c$-jets at $e^{+}{e}^{-}$ Higgs Factories with ParticleFlow detectors

Abstract

The Higgs boson decay modes to $b$ and $c$ quarks are crucial for many Higgs precision measurements. The presence of semileptonic decays in the jets originating from $b$ and $c$ quarks causes missing energy due to the undetectable neutrinos. A correction for the missing neutrino momenta can be derived from the kinematics of the decay up to a two-fold ambiguity. The correct solution can be identified by a kinematic fit, which exploits the well-known initial state at an $e^{+}{e}^{-}$ collider by adjusting the measured quantities within their uncertainties to fulfill the kinematic constraints. The ParticleFlow concept, based on the reconstruction of individual particles in a jet allows understanding the individual jet-level uncertainties at an unprecedented level. The modeling of the jet uncertainties and the resulting fit performance will be discussed for the example of the ILD detector. Applied to $H\to b\bar{b}/c\bar{c}$ events, the combination of the neutrino correction with the kinematic fit improves the Higgs mass reconstruction significantly, both in terms of resolution and peak position.

Based on the talk "Reconstruction of $b$- and $c$-jets at $e^{+}{e}^{-}$ Higgs Factories with ParticleFlow detectors" presented at the International Workshop on Future Linear Colliders (LCWS2021), Geneva, Switzerland, 15-18 March 2021