Fast shower simulation in the ATLAS calorimeter

E Barberio, J Boudreau, B Butler, SL Cheung, A Dell'Acqua, A Di Simone, W Ehrenfeld, MV Gallas, A Glazov, Z Marshall, J Mueller, R Plačakyte, A Rimoldi, P Savard, V Tsulaia, A Waugh, CC Young