The ${}^4\mathrm{He}\hspace{0.5em}\overrightarrow{p}{\hspace{0.5em}}^3\mathrm{H}\hspace{0.5em}\mathrm{pn}{\pi }^{+}$ reaction channel has been investigated at an incident ${}^4\mathrm{He}$ momentum of $8.6\hspace{0.5em}\mathrm{GeV}/c$ in an exclusive approach. It has been shown that the reaction mainly proceeds via $p\overrightarrow{p}\mathrm{pn}{\pi }^{+}$ interaction with $\left(p{\pi }^{+}\right)$ from ${\Delta }^{++},$ while triton is a spectator. The anisotropic angular distribution of the nucleons causes the splitting of ${(}^3\mathrm{H}n)$ invariant mass and leads to a natural separation of the interactions occuring either in proton or ${}^4\mathrm{He}$ vertices. Effects such as the shift of peak position in the $\left(p{\pi }^{+}\right)$ invariant mass distribution have not been observed.

• Received 8 July 1997

DOI:https://doi.org/10.1103/PhysRevC.59.405