Beam Test Results with a Highly Granular Analog Hadron Calorimeter Prototype (AHCAL)

To evaluate technologies for ILC calorimetry, the CALICE collaboration has constructed a prototype of a highly granular analog hadron sampling calorimeter with small scintillator cells, individually read out by silicon photomultipliers. This detector has been tested extensively in particle beams at DESY, CERN and Fermilab. The imaging capabilities of this detector provide three dimensional information of hadronic showers with unprecedented resolution and will thus help to constrain hadronic shower models in simulation codes. The high granularity also opens up the possibility for improved energy resolution achieved with energy weighting algorithms. Longitudinal and transverse shower profiles of hadronic events was compared to simulations with a variety of different models. The energy resolution and the linearity of the detector response as well as the unique possibility to decompose the hadronic shower into its electromagnetic, and hadronic components were studied.