Collectivity of the intruder bands in Sn-114

For the investigation of the collectivity and the structure of the intruder bands with positive and negative parity in Sn-114, coincidence lifetime me asurements using the recoil distance Doppler shift (RDDS) and the Doppler-s hift attenuation (DSA) methods were performed at the GASP spectrometer at t he INFN-Laboratori in Legnaro. Excited nuclear states were populated with t he reaction Mo-100(O-18,4n)Sn-114. For analysis the differential decay curv e method was used in the yy-coincidence mode. In total 31 lifetimes could b e obtained, belonging to 11 and 13 states in the positive- and negative-par ity intruder bands, respectively, and to 7 spherical states. This work enha nces our knowledge of low-lying collectivity among the Sn isotopes near the mid-shell region. (C) 2001 Elsevier Science B.V. All rights reserved.