Neutron-induced pion production on carbon, copper and bismuth at intermediate energies

Neutron induced pion production on C, Al, Cu, and W at neutron energies of 200--600 MeV

“…Most pion production measurements have supported tile theory that pion I)roduction takes piace on the surface of the nucleus [2].…”

“…These _r-:t "+ ratios can be compared to the ratios measured by Biichle [2] and Oganesyan [3] and calculated by LAHET. Biichle measured the ratio of _'-to _r+ 0.5 c,.p tr+ C, rt4-362.5 lvlev 562.5 k,le\.'…”

“…Cross sections for some energy and angular bins from carbon and copper can be compared to the cross section data taken by Biichle [2]. To compare our data with Bfichle's data which give cross sections for the sum of rr-and rr+ production, the Biichle data was reduced by a factor of 0.833.…”

“…There has been some evidence [27], [28], [2] It was found that the energy and angular distributions of both the rr-and rr+ data are very similar for the different nuclei and the two charge states, and the variation with neutron energy appears to be governed by the kinematics of the interaction. The Fernli motion of the nucleons causes the energy distributions to be extended to higher energies than would be available in free nucleon-nucleon interactions, and also reduces the production threshold relative to the free nucleonnucleon pion production threshold by at least 100 MeV.…”

Search for an enhanced production of low energy pions in C(p, π+)X, Cu(p, π+)X, and Cu(p, π∘)X reactions for 300 MeV≦Tp≦400 MeV

“…Another experiment [6] has not been able to positively identify excess pion production in neutron induced reactions, the observed bump being only 2.2 standard deviations in the most favorable case. In this case the resolution of the incoming beam was poor (3 MeV) for looking at a narrow resonance.…”