文摘
The upgrade of the DAΦNE machine layout requires a modification of the size and position of the inner focusing quadrupoles of KLOE2 thus asking for the realization of two new calorimeters covering the quadrupoles area. To improve the reconstruction of KL→2π0 events with photons hitting the quadrupoles, a tile calorimeter, QCALT, with high efficiency to low energy photons (20-300 MeV), time resolution of less than 1 ns and space resolution of few cm, is needed. We propose a tile calorimeter with a high granularity readout corresponding to about 2500 silicon photomultipliers (SiPM) of 1×1mm2 area. Moreover, the low polar angle regions need the realization of a dense crystal calorimeter with very high time resolution performances to extend the acceptance for multiphotons events. Best candidates for this calorimeter are LYSO crystals with APD readout or PbWO4 crystals with large area SIPM readout.
