Tile and crystal calorimeters for the KLOE 2 experiment

The upgrade of the DAΦNE machine layout requires a modification of the size and position of the inner focusing quadrupoles of KLOE ² thus asking for the realization of two new calorimeters covering the quadrupoles area. To improve the reconstruction of K→2π 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 1×1mm 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 PbWO ₄ crystals with large area SIPM readout.