  We propose to describe the process $ p ~ \bar{p} \rightarrow \pi^+ ~ \pi^-$
in a perturbative, QCD motivated framework in which a hard $ud \, \bar{u}
\bar{d} \rightarrow d \, \bar{d} $ annihilation factorizes from soft transition
distribution amplitudes. We advocate that the scale allowing for this
factorization is the large transverse momentum transfer. In our simplified
model, in which the proton is considered as a (scalar)diqark-quark system, a
transition distribution amplitude describes the non-perturbative transition of
the proton to the meson by emission of a scalar, isoscalar $ ud $-diquark and
absorption of an antiquark (analogously for $ \bar{p} \rightarrow \pi^- $). We
model the transition distribution amplitudes as an overlap of light-cone wave
functions and present first results for the differential cross section. This
process will be measured by the $ \bar{\mbox{P}}$ANDA experiment at GSI-FAIR.
