  Hadronic calorimeters with dual readout measure both scintillation and
Cherenkov lights produced in their active media. They offer improvements in
energy resolution and, therefore, have become increasingly interesting due to
the need for precision jet measurements at Higgs factories. This paper presents
Geant4 simulations of single-particle responses in sampling and homogeneous
calorimeters, and demonstrates the effect of inclusion of Cherenkov light in
the reconstruction of energies. The simulations are performed with a
single-photon precision.
