A Silicon-Tungsten ECal with Integrated Electronics

We summarize recent R and D progress for a silicon-tungsten electromagnetic calorimeter (ECal) with integrated electronics, designed to meet the ILC physics requirements. A basic physics requirement for ILC detectors is that they provide excellent reconstruction of hadronic final states. This allows access to new physics which is complementary to the LHC. One statement for a requirement on jet reconstruction is that intermediate particles which decay into jets, such as W, Z, or top, can be identified and isolated. This places unprecedented requirements on 2-jet or 3-jet mass resolution, typically at the level of 3-5% using the PFA technique, which makes challenging demands on the calorimeters. The electromagnetic energy resolution is not expected to limit jet resolution using a PFA. However, particle separation - photon-photon and charged hadron-photon - is crucial. In addition, if one provides this kind of imaging calorimeter to meet the PFA needs, these same features will also be put to good use for reconstruction of specific tau decay modes (to enable final-state polarization measurement), to 'track' photons (even if originating from a vertex displaced from the interaction point), to track MIPS, and so forth. Figure 1 and Table 1 provide some context for our ECal design within the SiD detector concept, along with some main design parameters. More detail is included in the presentation.