On formation of exotic particles at channeling of low energy antiprotons in LiH crystals

Abstract

In this work we propose a new method to form both protonium exotic $\mathrm{p}\overline{\mathrm{p}}$ and lithium antiproton $\overline{\mathrm{p}}{\mathrm{Li}}^{+}$ atoms by capturing the hydrogen H⁻ and lithium Li⁺ ions of the LiH crystal lattice at planar or axial channeling of low-energy antiproton beams. Within sudden-perturbation approximation the probability for protons as well as for ions to be bound into different quantum levels defined by the antiproton Coulomb potential are calculated. It is shown that the probability strongly depends on the parameters of channeled antiprotons revealing various extremes (resonances): the functions of capture probabilities for all excited quantum states of antiproton are characterized by three most intense peaks. Higher probability to form heavier particles, namely antiproton lithium $\overline{\mathrm{p}}{\mathrm{Li}}^{+}$, have been demonstrated.