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

TL;DR

This paper explores how ParticleFlow detector techniques and kinematic fitting can improve the reconstruction of $b$- and $c$-jets in Higgs decay measurements at $e^{+}e^{-}$ colliders, enhancing mass resolution and accuracy.

Contribution

It introduces a method combining neutrino momentum correction with kinematic fitting using ParticleFlow data to improve jet reconstruction in Higgs decay analysis.

Findings

Significant improvement in Higgs mass resolution.

Enhanced peak position accuracy in reconstructed mass.

Effective modeling of jet uncertainties with ParticleFlow.

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 $H\rightarrow b\bar{b}/c\bar{c}$ 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.