Exploring the collective spin-isospin longitudinal response of nuclei with coherent pion production in ($^3$He,t$\pi$^+$)
Résumé
The SATURNE charge-exchange program explored the spin-isospin response of nuclei in the Delta region. New results on coherent pion production are presented. They give a precise measure of the spin longitudinal component of this response. This component is particularly interesting since theoretical models predict that attractive residual Delta -hole correlations in the longitudinal channel (pion exchange) softens the response.