Degradation of resolution in a homogeneous dual-readout hadronic calorimeter

Abstract

If the scintillator response to a hadronic shower in a semi-infinite uniform calorimeter structure is S relative to the electronic response, then S/E=[fem+(1−fem)(h/e)], where E is the incident hadron energy, fem is the electronic shower fraction, and h/e is the hadron/electron response ratio. If there is also a simultaneous readout with a different h/e, say a Cherenkov signal C, then a linear combination of the two signals provides an estimator of E that is proportional to the incident energy and whose distribution is nearly Gaussian—even though the S and C distributions are non-linear in E, wide, and skewed. Since an estimator of fem is also obtained, it is no longer a stochastic variable. Much of the remaining resolution variance is due to sampling fluctuations. These can be avoided in a homogeneous calorimeter. The energy resolution depends upon the contrast in h/e between the two channels. h/e is small in the Cherenkov channel. Mechanisms that increaseh/ein sampling calorimeters with organic scintillator readout are not available in a homogeneous inorganic scintillator calorimeter. The h/e contrast is very likely too small to provide the needed energy resolution.