par Baye, Daniel Jean ;Dohet-Eraly, Jérémy
Référence Physical Review A, 101, 2, 022507
Publication Publié, 2020-08-01
Article révisé par les pairs
Résumé : Accurate three-body quantal calculations of the system composed of a proton, an antiproton, and an electron are performed in perimetric coordinates with the Lagrange-mesh method, an approximately variational calculation with the simplicity of a calculation on a grid. Quasibound states with respect to the p + H(n=2) threshold are obtained for L=60-73 for various vibrational excitations. Their energies have accuracies up to about 10-14 atomic units, while less precise energies are determined for L=56-59 broader resonances. Their structure is analyzed with the help of mean distances between the particles. These mean distances indicate that the proton-electron subsystem is in excited states, mostly n=2, as predicted by Sakimoto [Phys. Rev. A 98, 042503 (2018)2469-992610.1103/PhysRevA.98.042503] with the Born-Oppenheimer approximation. A comparison performed with this approximation provides the accuracies of its energies and of its proton-antiproton mean distances.