Pairing dynamics and solitonic excitations in collisions of medium-mass, identical nuclei

We present results of collisions of 90Zr + 90Zr and 96Zr + 96Zr obtained within time-dependent density functional theory (TDDFT) extended to superfluid systems, known as the time-dependent superfluid local density approximation (TDSLDA). We discuss qualitatively new features occurring in collisions of two superfluid nuclei at energies in the vicinity of the Coulomb barrier. We show that a solitonic excitation???an abrupt pairing phase for capture, generating effective repulsion between colliding nuclei. Moreover we demonstrate that pairing field leads to qualitatively different dynamics at the Coulomb barrier which manifests itself in a slower evolution of deformation towards a compact shape. Last but not least, we show that magnitude of pairing correlations can be dynamically enhanced after collision. We interpret it as a dynamically induced U(1) symmetry breaking, which leads to large-amplitude oscillations of pairing field and bears similarity to the pairing Higgs mechanism.

Automated summary

This study investigates the collisions of 90Zr + 90Zr and 96Zr + 96Zr using the time-dependent superfluid local density approximation (TDSLDA), revealing new features in the collisions of two superfluid nuclei near the Coulomb barrier. These features include abrupt pairing phase for capture, effective repulsion between colliding nuclei, slower evolution of deformation towards a compact shape, and dynamically enhanced pairing correlations.