Spin Dependence in the Excitation of the First2+State ofFe54

Proton-$\gamma$ angular-correlation measurements at 19.6 MeV, together with asymmetry data for excitation of the first $2^{+}$ state of ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$, yield strong evidence for the full Thomas form of the spin-dependent collective-coupling potential. In addition, the agreement between these data and calculations is improved when the spin-dependent deformation ${\beta }_{\mathrm{s}.\mathrm{o}.\mathrm{}}$ is twice ${\beta }_2$, the deformation parameter for the central potential.