Pseudorapidity determination with the electromagnetic end cap calorimeter

Possible improvements in the pseudorapidity determination using the end cap of the electromagnetic calorimeter are examined. A method for determining the shower barycenters in the calorimeter samplings is presented. In addition, a new S-shape correction function in the form of a truncated Fourier series is calculated separately for each eta value. These methods are applied to the measurement of the pseudorapidity and vertex z-coordinate using the end cap of the electromagnetic calorimeter. The pseudorapidity resolution is compared with that required for the detection of the decay Higgs--> gamma gamma.