Precision physics at future colliders requires highly granular calorimeters to support the Particle Flow Approach for event reconstruction. This article presents a review of about 10 - 15 years of R&D, mainly conducted within the CALICE collaboration
, for this novel type of detector. The performance of large scale prototypes in beam tests validate the technical concept of particle flow calorimeters. The comparison of test beam data with simulation, of e.g. hadronic showers, supports full detector studies and gives deeper insight into the structure of hadronic cascades than was possible previously.
The talk summarises the case for Higgs physics in $e^+e^-$ collisions and explains how Higgs parameters can be extracted in a model-independent way at the International Linear Collider (ILC). The expected precision will be discussed in the context of
projections for the experiments at the Large Hadron Collider (LHC).
The CALICE analog HCAL is a highly granular calorimeter, proposed for the International Linear Collider. It is based on scintillator tiles, read out by silicon photomultipliers (SiPMs). The effects of gaps between the calorimeter tiles, as well as th
e non-uniform response of the tiles, in view of the impact on the energy resolution, are studied in Monte Carlo events. It is shown that these type of effects do not have a significant influence on the measurement of hadron showers.
