Isovector E2/E0 strength in ^<28>Si studied by the (e, e\u27n) reaction II(I. Nuclear Physics)

We have measured the ^Si (e, e\u27n) reaction in the excitation energy range 28.5- 39.5 MeV which is higher than that in the previous experiment. The obtained E1 strength agreed with that of the photoreaction. The E2-E0 component below 22 MeV showed a difference to that of the (e, e\u27p_^) reaction and was similar to the (e, e\u27 α_1) and ( α, α \u27) reactions which contain dominantly isoscalar resonances. In the higher energy, the present E2-E0 data have a broad bump from 23 to 35 MeV which is not seen in the (α, α\u27) reaction ; it is thought to be attributed to the isovector excitation. This interpretation is partially supported by the result of the ^Si(^7Li, ^7Be) ^Al experiment