Hadronic response and e / pi separation with the H1 lead / fiber calorimeter

Hadronic response and electron identificationperformance of the new H1 lead-scintillating fibre calorimeter are investigated in the 1 to 7 GeV energy range using data taken at the CERN Proton Synchrotron. The energy response to minimum ionizing particles and interacting pionsare studied and compared to Monte Carlo simulations. The measured energy of pionsinteracting either in the electromagnetic or in the hadronic section is found to scale linearly with the incident energy, providing an energy resolution σE ∼ 38% within a depth of one interaction length and σE ∼ 29% for a total depth of two interaction lengths. Several electron identificationestimators are studied and combined as a function of energy and impact point. The probability for pionsto be misidentified as electrons of any measured energy above 1 GeV ranges from 5% (for 2 GeV incident pions) to 0.4% (at 7 GeV) for an electron detection efficiency of 90%. The probability for pionsof a given energy to be misidentified as electrons of the same energy falls to 0.25% at 7 GeV.