Calculations of antiproton-nucleus quasi-bound states using the Paris $\bar{N}N$ potential

Abstract

An optical potential constructed using the ${\bar p}N$ scattering amplitudes derived from the 2009 version of the Paris ${\bar N}N$ potential is applied in calculations of ${\bar p}$ quasi-bound states in selected nuclei across the periodic table. A proper self-consistent procedure for treating energy dependence of the amplitudes in a nucleus appears crucial for evaluating ${\bar p}$ binding energies and widths. Particular attention is paid to the role of $P$-wave amplitudes. While the $P$-wave potential nearly does not affect calculated ${\bar p}$ binding energies, it reduces considerably the corresponding widths. The Paris $S$-wave potential supplemented by a phenomenological $P$-wave term yields in dynamical calculations ${\bar p}$ binding energies $B_{\bar p}\approx 200$ MeV and widths $\Gamma_{\bar p}\sim~200 - 230$ MeV, which is very close to the values obtained within the RMF model consistent with ${\bar p}$-atom data.