CMS Endcap Calorimeter Energy Resolution with Additional Active Layers between ECAL and HCAL

Energy resolution for hadrons of the combined calorimeter including the Endcap hadron calorimeter ( HCAL) and the Endcap electromagnetic calorimeter ( ECAL) has been studied as a function of energy for several configurations of the HCAL using GEANT 3.21 package. Relative energy resolution is compared for the HCAL alone, the ECAL+HCAL, the ECAL+HCAL with independent weight for the first scintillator ( S2) of the HCAL, and with an additional layer ( S1) after the ECAL. Calculations have been performed for single protons, as well as for spectator jets, produced by protons in 8 cm Be target.