Electroexcitation of discrete levels inC12andC13at high momentum transfers

Form factors for transverse electron scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ have been determined for momentum transfers as high as q=4.6 ${\mathrm{fm}}^{\mathrm{-}1}$. Data are presented for the elastic (M1), 3.088 MeV (E1), and 9.50 MeV (M4) transitions in ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$, and for the 15.11 MeV (M1), 16.11 MeV (E2), and 16.58 MeV (M2) transitions in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$. It is found that calculations in the lowest-order shell-model space fail to account for the measured q dependences of E1, M1, and E2 form factors beyond q=2 ${\mathrm{fm}}^{\mathrm{-}1}$. On the other hand, form factor shapes observed for M2 and M4 multipoles are satisfactorily described to q=4 ${\mathrm{fm}}^{\mathrm{-}1}$ within the minimal 1ħω configuration space.