A direct evidence of 2ħ-high single particle component has been obtained for the first time in sd-shell nuclei from measurement of ${\alpha }_0$ and ${\mathrm{p}}_0$ decay from the 12.80 MeV state in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ populated through the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{20}$Ne,α${)}^{28}$Si reaction. This state is assigned $J^{\pi }$${=6\mathrm{}}^{+}$ and has a $g_{9/2}$ single particle component of 20–30 % in a nearly stretched proton configuration of ($g_{9/2}$$d_{5/2}^{\mathrm{-}1}$).

• Received 30 April 1985

DOI:https://doi.org/10.1103/PhysRevC.33.1524