Deviation from tidal symmetry for scattering ofpolarized23Nafrom the deformed nucleus27Al

The second-rank analyzing powers T20 and TT20 were measured using a tensor-polarized beam of 23Na scattered from 27Al at an incident energy of 150 MeV. The concept of tidal symmetry in scattering systems leads directly to a shape-effect relationship between the two sets of analyzing powers which should hold good at low values of the isocentrifugal parameter and this has been confirmed in other scattering systems. For 23Na1 27Al at 150 MeV the isocentrifugal parameter has the low value of 0.04, yet the shape effect relations do not hold true for the data forward of 12° c.m. It is suggested that this may be evidence for an effect of the deformation of the target nucleus and this is supported by coupled-channel calculations which agree well with the data.