Pure Alpha-Pb-208 States In Po-212 Revealed By Their Enhanced E1 Decays: A Novel Alpha Clustering

International audienceExcited states in Po-212 have been populated by alpha transfer using the Pb-208(O-18, C-14) reaction and studied with the Euroball gamma multidetector array. Very enhanced El transitions have been revealed by very short lifetimes measured by the DSAM method, found in the [0.1-1.4] ps range. The emitting states, which have non-natural parity values, are the fingerprints of the "alpha-Pb-208" structure present in Po-212. They are in the same excitation-energy range as the states issued from shell-model configurations