Electroexcitation of the<i>Δ</i>(1232) in nuclei

Abstract

Inclusive electron-scattering measurements of \ensuremath{\Delta} electroexcitation in nuclei are reported. Electrons with energies of 0.96, 1.1, 1.3, and 1.5 GeV were scattered from $^{1}\mathrm{H}$, $^{4}\mathrm{He}$, C Fe, and W at 37.5\ifmmode^\circ\else\textdegree\fi{}, corresponding to ${Q}^{2}$=0.20--0.52 (GeV/c${)}^{2}$ at the \ensuremath{\Delta} peak. The centroid of the \ensuremath{\Delta}-region cross-section peak is above that for the free nucleon and it shifts to higher invariant mass as ${Q}^{2}$ increases. The A dependence in the dip region and ratios of nuclear to nucleon integrated cross sections indicate that at these ${Q}^{2}$ values there is little specifically nuclear, e.g., quasideuteron, background contribution.