{Delta} excitations in nuclei and the coherent pion decay

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:387268

Udagawa, T; Koerfgen, B; Oltamanns, P; Osterfeld, F

The (p,n) and ({sup 3}He, t) reactions at intermediate energies have shown that there is a substantial downward energy shift in the excitation spectra of the {Delta} resonance in nuclei compared with the corresponding spectra in the Proton target. Part of this shift, is caused by a coherent medium effect on the spin-longitudinal response function. The coherent, effect is produced by the attractive {pi} exchange interaction between {Delta}-hole states in the medium. Evidence of such a coherent mode has recently been obtained in the {sup 12}C(p, n{pi}) and {sup 12}C({sup 3}He, {pi}) reaction. In this paper, we report results of our calculations or the coherent pion production cross sections. It is shown that the coherent pions provide a unique signature on the nuclear pionic mode; they have a peak energy of E{sub {pi}} = 250 MeV and a strongly forward peaks angular distribution. It is now important that these results are confirmed and checked by other experiments, such as the {sup 12}C({tilde n}, {tilde n}{pi}{sup +}) spinflip transfer experiments at LANPF and {sup 12}C(e, e`{pi}{sup 0}) experiments at CEBAF.

• OSTI ID: 387268
• Report Number(s): CONF-931044--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 9 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CARBON 12 TARGET
DELTA-1232 BARYONS
EXCITATION
HELIUM 3 REACTIONS
PARTICLE PRODUCTION
PIONS
PROTON REACTIONS