α-ParticleD-State Components from (d,α) Analyzing Powers

Abstract

A $D$-state component in the $\alpha$ particle has been extracted from angular distributions of tensor analyzing powers for ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}(d,{\alpha }_0){}_{}{}^{87}{}_{}{}^{}\mathrm{Sr}$ at 9, 12, and 16 MeV. Exact finite-range distorted-wave Born-appproximation analyses including the effects of $L$ and $J$ mixing have been performed. The $D$-state parameter $D_2$, closely related to the asymptotic $D$- to $S$-state ratio for $d-d$ relative motion in the $\alpha$ particle, requires a value of $D_2=-0.3\mathrm{}\pm 0.1$ ${\mathrm{fm}}^2$ in order to fit the tensor analyzing power data.