Sensitivity of reaction cross sections to halo nucleus density distributions.

Measurements of reaction cross sections are routinely used to deduce effective nuclear root mean square ~rms! radii by comparison with theoretical model predictions. Cross sections calculated using the optical limit Glauber model depend strongly on the rms radius of the density assumed for the projectile nucleus. We investigate such calculations by assuming a range of projectile density distributions. We show that calculated Li-target cross sections at fixed rms radii retain a significant sensitivity to higher radial moments of the projectile density which is quite different for light and heavy targets. @S0556-2813~96!02905-6#