Search for the ${\Delta }^{++}$ component in ${}^{12}C$ ground state using ${}^{12}C(\gamma ,{\pi }^{+}p)$ reaction

Abstract

The differential cross section for the reaction ${}^{12}$C$(\gamma ,{\pi }^{+}p)$ has been measured in the $\Delta$ resonance region at high recoil momenta of the residual nuclear system. The data are analysed under the assumption that the formation of ${\pi }^{+}p$ pairs may be interpreted as $\gamma {\Delta }^{++}\to {\pi }^{+}p$ process, proceeding on the ${\Delta }^{++}$ constituent in a target nucleus. As a result, the estimation $N_{\Delta }=0.028\pm 0.008$ deltas per nucleon in ${}^{12}$C was obtained.

LaTeX, 8 pages, 3 Postscript figures, submitted to Rhys. Lett. B