Quantum Calculation of the Collision-Induced Line-Shape Effects in Antiprotonic Helium and the New Accurate Ab Initio p¯He+-He Potential Energy Surface.

ABSTRACT: We present the first fully ab initio calculations of collision-induced broadening and shift of spectral lines in antiprotonic helium (p¯He+) perturbed by atomic helium. To overcome critical limitations of previous studies, we construct a new highly accurate potential energy surface (PES) that spans a wide range of p¯He+-He geometries relevant to all metastable states of the exotic helium atom. Rigorous quantum scattering calculations performed using the new PES yield scattering S-matrices from which we extract pressure broadening and shift coefficients for 50 transitions in antiprotonic helium-4 (p¯4He+). This data set provides the first rigorous benchmark for earlier semiclassical calculations and establishes a robust theoretical reference for high-precision spectroscopy of antipro

SUBMITTER: Jozwiak HJ 

PROVIDER: S-EPMC12805563 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature