Multinucleon Removal in 220-MeVπ−Reactions withA<~51Nuclei

Abstract

We have detected and identified prompt $\gamma$ rays from residual formed in 220-MeV ${\pi }^{-}$ reactions with C, F, O, Mg, Al, Si, S, Ca, and V. Cross sections for $2n+2p$ removal from the even-$A$, even-$Z=N$ targets are found to be camparable to inelastic cross sections; multiple-($2n+2p$)-removal cross sections are also large. For the odd-$A$ target, ($n+2p$)-and ($2n+2p$)-removal cross sections are of the same order as inelastic cross sections. The results are campared with previously reported hadron-induced $\alpha$-particle-removal cross sections.