Nonlinear energy-loss straggling of protons and antiprotons in an electron gas

TL;DR

This paper investigates how protons and antiprotons lose energy in an electron gas, revealing that quadratic corrections significantly reduce energy-loss fluctuations at low and intermediate velocities, especially for antiprotons.

Contribution

It provides a detailed analysis of nonlinear energy-loss straggling using quadratic response theory and RPA, highlighting the importance of quadratic corrections for antiprotons.

Findings

Quadratic corrections significantly reduce energy-loss straggling at low velocities.

Antiprotons experience more pronounced effects from quadratic corrections than protons.

Results are obtained within a homogeneous electron gas model using RPA.

Abstract

The electronic energy-loss straggling of protons and antiprotons moving at arbitrary nonrelativistic velocities in a homogeneous electron gas are evaluated within a quadratic response theory and the random-phase approximation (RPA). These results show that at low and intermediate velocities quadratic corrections reduce significantly the energy-loss straggling of antiprotons, these corrections being, at low-velocities, more important than in the evaluation of the stopping power.