Cornell University Unit Name

"Investigation of ECAL Concepts Designed for Particle Flow"

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The goal of this R&D project is to investigate electromagnetic calorimeter design concepts matched to the linear collider physics program with principal design criteria of i) hermeticity, ii) precise measurement of jet energies using particle flow and iii) suited to a general purpose experiment. These criteria are closely tied to the overall detector design concept and the work undertaken is very relevant to assessing the relative merits of the LDC, GLD and SiD approaches.

Recent results include:

i) ECAL clustering studies with nearest-neighbor and fixed-cone algorithms.

ii) Photon identification studies using the H-matrix approach.

iii) Investigating pi0 kinematic fits to improve pi0 energy resolution in jets. This work points towards ultra-fine granularity in the first layers of the ECAL and/or large radius.

Current work has contributed in part to development of particle-flow algorithms. Once these algorithms are more mature and robust, one can envisage estimating the specific impact of different ECAL designs on the overall particle flow performance. In the near future, we will concentrate on a quantitative understanding of the relative importance of the different sources of confusion (eg. photon/hadron separation) in particle flow performance. This should aid in understanding how much detector R&D should be aimed at ECAL or HCAL technologies.

The project lacks sufficient resources to make adequate timely progress on these issues while fulfilling critical commitments to a running experiment.