Quadrupole and Octupole Excitations of the Even Tin Isotopes by Electron Scattering

Form factors obtained by the inelastic scattering of 60-MeV electrons from the first $2^{+}$ and $3^{-}$ collective states of ${\mathrm{Sn}}^{116}$, ${\mathrm{Sn}}^{118}$, and ${\mathrm{Sn}}^{120}$ are reported. The momentum transfer range covered is 0.3-0.6 ${\mathrm{F}}^{-1\mathrm{}}$. Reduced transition probabilities $B\left(\mathrm{EL}\right)\mathrm{}$ and transition radii $R_{\mathrm{tr}}^{}{}_{}{}^2$ are extracted from the data, using a transition charge distribution with a radial dependence given by the derivative of a Fermi charge distribution, and the distorted-wave code DUELS. In addition, the parameters $c$ and $t$ for a ground-state Fermi charge distribution, obtained by elastic scattering, are reported for ${\mathrm{Sn}}^{116}$, ${\mathrm{Sn}}^{118}$, ${\mathrm{Sn}}^{120}$, and ${\mathrm{Sn}}^{124}$.