Determining theC12(α,γ)O16cross section from Coulomb dissociation

We estimate the E1 and E2 contributions to the Coulomb dissociation reaction ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$+Pb→α${+}^{12}$C+Pb using semiclassical Coulomb excitation theory. For projectile energies below 300 MeV/nucleon and scattering angles greater than 1°, we find that the process is dominated by the E2 component. This is in contrast to the astrophysically interesting ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(α,γ${)}^{16}$O cross section, which is dominated by the E1 multipole at the most effective energy of 300 keV. The E2 sensitivity of Coulomb dissociation would usefully complement forthcoming ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$ β-decay data, which will constrain only the E1 component.