Collision-induced absorption and annihilation in hadronic atoms within a close-coupling approach

Abstract

The induced absorption or annihilation of ${\ensuremath{\pi}}^{\ensuremath{-}}$, ${K}^{\ensuremath{-}}$, and $\overline{p}$ in collisions of hadronic hydrogen atoms in excited states with ordinary hydrogen in the ground state is treated in a unified manner with the elastic scattering, Stark transition, and Coulomb de-excitation in the framework of the close-coupling approach. The close-coupling approach is generalized to include both open andclosed channels corresponding to stable and unstable states of the hadronic atom. Calculations are performed using the basis sets including all states of hadronic atoms with a principal quantum number from $n=1$ up to ${n}_{\mathrm{max}}=8$. The general features of induced-absorption cross sections are studied in a wide range of complex energy-shift values. The cross sections of all processes are calculated for ${\ensuremath{\pi}}^{\ensuremath{-}}p$, ${K}^{\ensuremath{-}}p$, and $\overline{p}p$ atoms with principal quantum numbers $n=2$--8 and kinetic energies from 0.001 up to 100 eV. The validity of the previous quantum-mechanical and semiclassical models is critically discussed.