Compensating hadron calorimeters with Cerenkov light

Because only a small fraction ( approximately 10%) of the energy deposition in the purely hadronic portion of a hadron shower is by minimum ionizing particles, the authors investigated the possibility of compensating calorimetry in homogeneous transparent materials by measuring separately the ionization energy (by scintillation or drifted ions) and the Cerenkov light. This can be used to separate the electromagnetic fluctuations in the shower, thereby correcting calorimeter response. They discuss potential media and methods to accomplish this, together with calculated responses. The possibility of compensation with a constant term less than 0.5% has been demonstrated in a highly idealized liquid argon device. Resolution for hadrons in the ideal case is shown to be comparable to that of heterogeneous calorimeters and offers the option of using the Cerenkov compensation at high energies and using ionization alone at low energies. In principle, such calorimeters could have superior electron resolution and substantial e/ pi separation, relative to most hadron calorimeters. Several configurations are suggested as ways to realize these devices, but a practical device awaits further detailed Monte Carlo studies and design.<
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