Dynamic screening and energy loss of antiprotons colliding with excited Al clusters

TL;DR

This study uses time-dependent density functional theory to analyze how excited aluminum clusters affect the energy loss of colliding antiprotons, revealing that excited clusters transfer less energy than ground state clusters.

Contribution

It introduces a detailed quantum mechanical analysis of energy transfer differences between excited and ground state aluminum clusters during antiproton collisions.

Findings

Excited Al clusters transfer less energy to antiprotons than ground state clusters.

Non-linear electronic response effects are significant at certain velocities.

The energy transfer difference correlates with the cluster excitation spectrum.

Abstract

We use time-dependent density functional theory to calculate the energy loss of an antiproton colliding with a small Al cluster previously excited. The velocity of the antiproton is such that non-linear effects in the electronic response of the Al cluster are relevant. We obtain that an antiproton penetrating an excited cluster transfers less energy to the cluster than an antiproton penetrating a ground state cluster. We quantify this difference and analyze it in terms of the cluster excitation spectrum.