Total cross sections of the charge exchange reaction(π+,π0) on2H,3He, and4He across theΔ(1232)resonance

Abstract

Results from a $4\ensuremath{\pi}$ solid angle measurement of the inclusive reaction $({\ensuremath{\pi}}^{+},{\ensuremath{\pi}}^{0})$ on ${}^{2}$H, ${}^{3}$He, and ${}^{4}$He at incident pion energies of ${T}_{{\ensuremath{\pi}}^{+}}=70$, 118, 162, 239, and 330 MeV are presented. The single charge exchange total cross sections were determined, and are compared to previous results and simple models of $\ensuremath{\pi}$--few-nucleon interactions. On the helium isotopes a strong damping of the cross sections in the $\ensuremath{\Delta}(1232)$ energy region is observed. Total cross sections of the breakup reaction ${\ensuremath{\pi}}^{+}{+}^{2}$H $\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}\mathrm{pn}$ are also given.