Multiphonon couplings in the sub-barrier fusion of 36S+140Ce

Fusion cross sections have been measured for the system 36S + 140Ce in the energy range encompassing the Coulomb barrier. A representation of the fusion barrier distribution has been obtained from the second energy derivative of the excitation function. The data are well described by coupled‐channels calculations including two‐phonon states of quadrupole and octupole character in the target (140Ce) and one octupole phonon in the projectile. The importance of 140Ce low‐lying inelastic excitations has been pointed out.