Observation of Spin Flip inC13+Mg24Inelastic Scattering

Evidence for spin-dependent interactions in heavy-ion reactions has been found in the inelastic scattering of 35-MeV ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ from the 1.368-MeV, $2^{+}$ state in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$. $\gamma$ rays emitted perpendicular to the reaction plane have been measured and $\mathrm{}\left|m\right|\mathrm{}$-substate populations deduced. At ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ scattering angles ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=10\mathrm{}° \mathrm{and} 21°$, probabilities for the $\mathrm{}\left|m\right|=1\mathrm{}$ population (which is equivalent to spin flip) are found to be (1.7±0.5)% and less than 0.8%, respectively.