A STUDY OF THE TIME EVOLUTION OF RESONANCE STATES IN ATOMIC POTASSIUM USING ULTRASHORT LASER PULSES. E Sokell, S Zamith, V Blanchet, M A Bouchene and B Girard. Laboratoire de Collisions Agr?gats R?activit? (CNRS UMR 5589), IRSAMC, Universit? Paul Sabatier, 118 Route de Narbonne, 31602, Toulouse, France.