Comment on 'Anomalies in the Electronic Stopping of Slow Antiprotons in LiF', arXiv:2501.14381

Abstract

This work contains detailed discussions on the contents of Phys. Rev. Lett. 134, 076401 (2025), in the following denoted PRL134. In this comment, we revisit and elaborate on the Adiabatic Ionization Model (AIM) for the energy loss of antiparticles in matter, with particular reference to its theoretical foundation as established previously. The AIM framework plays a central role in describing the ionization dynamics in the low-velocity regime considered by the authors of PRL134. Calculated AIM results for the energy loss of antiprotons in LiF crystals are compared to experimental data and different other models, pointing to severe problems of the PRL134 results. Beyond this specific comparative theoretical investigation, we critically examine several statements and assumptions made in PRL134. Certain claims presented therein appear to be inconsistent with established theoretical principles or are insufficiently justified by the data and arguments provided. As such, we believe that further clarification, and in some cases, a more rigorous justification, is necessary to substantiate those points.