Estimate of the $\Delta(1232)$ component in the $^{12}$C nucleus

The cross section for the $^{12}$C($(\gamma ,\pi^{+}p)$) reaction was measured in the range of the $\Delta(1232)$ isobar. The data were analyzed using the models taking into account the nucleon and isobaric degrees of freedom of the $^{12}$C nucleus. The conclusion is drawn that in the large-momentum transfer range the $\pi^+p$ pairs are produced in the course of the direct knocking-out of $\Delta^{++}$ isobar from the nucleus. The probability of finding the $\Delta$ isobar in the ground-state $^{12}$C nucleus is estimated at $0.018\pm0.005\Delta$ isobars per nucleon.