On the bosonic atoms

We investigate here ground state properties of atoms, in which substitute fermions -- electrons by bosons, e.g. $\pi$ - meson. We perform some calculations in the frame of modified Hartree-Fock (HF) equation. The modification takes into account the symmetry, instead of anti-symmetry of the two-identical bosons wave function. The modified HF approach thus enhances (doubles) the effect of self-action for the boson case. Therefore, we accordingly modify the HF equations by eliminating from them the self-action terms artificially. We found the binding energy of $\pi$ - meson negative ions of $\pi$ - meson atoms and the number of extra bound $\pi$ - meson increases with the growth of nuclear charge Z. For e.g. for Xe even four times charged negative ion exists. As an example of a simple process with a pion atom, we consider photoionization that differs essentially from that for electron atoms. Namely, it is not monotonic decreasing from the threshold but has a prominent maximum above threshold instead. We study also elastic scattering of pions by $\pi$ - meson atoms.