Crystals for dual-readout calorimetry

Dual-Readout Calorimetry is a promising new technique for high resolution calorimetry. It is based on simultaneous measurements of the scintillation and Cherenkov light generated in the shower development process. Due to the fact that the Cherenkov light is only produced by the electromagnetic shower component, the relative contribution of this component to the signals can be measured on the event by event basis, resulting in reduction of fluctuations. This leads to an important improvement in the hadronic calorimeter performance. Further improvement on both the electromagnetic and hadronic resolution can be achieved by using homogeneous, dense crystals. This reduces both the sampling fluctuations and the quantum fluctuations. Promising results have been obtained by using PbW 0 4 crystals doped with small amounts of praseodymium or molybdenum. Results from the 2008 testbeam and perspective for the coming one this year will be shown.