SEMINAR      Tuesday, 9 March 2004 - h. 15:00  Aula Seminari (A34)     Richard Wigmans (Texas Tech Univ. & INFN Frascati) D R E A M – about high-resolution jet spectroscopy Abstract High-precision jet spectroscopy will be increasingly important in future high-energy accelerator experiments, particularly at a Linear e+e− Collider. In this talk, I will briefly review the options that are being pursued in the quest to measure the properties of the hadronic constituents of matter with a precision comparable to what is commonly achieved for leptons. Then, I will present recent results of prototype studies of DREAM (Dual REAdout Module), a novel type of calorimeter that is based on simultaneously measuring the scintillation light and the ˇCerenkov light generated in the shower development process. By comparing these two signals, the electromagnetic shower fraction can be measured event by event, both for single hadrons and for jets. Fluctuations in this fraction are the dominant contribution to the hadronic energy resolution. They are also responsible for the signal non-linearity and the non-Gaussian response function typical for hadron calorimeters. The dual-readout technique makes it possible to eliminate the effects of these fluctuations. As a result, the DREAM calorimeter has impressive performance characteristics.