Workshop for young scientists with research interests focused on physics at FAIR

We propose to describe the process $ p \bar{p} \rightarrow \pi^- pi^+ $ in a perturbative QCD motivated framework where a double-handbag hard process $ ud \bar{u} \bar{d} \rightarrow d \bar{d} $ factorizes from transition distribution amplitudes (TDAs). A TDA describes the non-perturbative transition of the proton to the meson by emission of 2 quarks and absorption of an antiquark (analogously for the $ \bar{p} \rightarrow \pi^- $). We advocate that the scale allowing this factorization is the large transverse momentum transfer. We calculate this process in a simplified framework in which the proton is considered as a quark-(scalar) diqark. We model the TDAs as overlaps of ight-cone wave functions and present the expected cross sections for the PANDA experiment at GSI-FAIR.