Severe Inhibition of Fusion by Quasifission in Reactions Forming [Formula presented]

Abstract

Evaporation residue cross sections have been measured following the fusion of [Formula presented] with [Formula presented], forming the compound nucleus [Formula presented]. These are compared with existing data for the same compound nucleus formed following fusion reactions with [Formula presented], [Formula presented], [Formula presented], and [Formula presented] projectiles. At energies where the reduced cross sections of [Formula presented] evaporation residues would be expected to be the same for all reactions, those for the heavier projectiles are typically a factor of 10 smaller than those for [Formula presented]. This inhibition is attributed to strong competition of quasifission with fusion at the low angular momenta associated with evaporation residue formation. Show more