Nucleon polarization in three-body models of polarized 6Li.

Abstract

Just as [sup 3]H[rvec e] can be approximately characterized as a polarized neutron target, polarized [sup 6]LiD has been advocated as a good [ital isoscalar] nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed alpha + deuteron'' picture of [sup 6]Li, with the polarization of the nucleus carried by the polarization of the deuteron. We have calculated the polarization of the constituents of [sup 6]Li as a three-body bound state of [alpha]+[ital n]+[ital p] interacting with local potentials fitted to the scattering data. It is necessary to include partial waves up to [ital j]=17/2 (75 channels, or, when including the [ital T]=1 state, 150 channels) in the Faddeev equations before the energy eigenvalue converges. The longitudinal form factors are then described well by the wave function. Various combinations of [alpha][ital N] and [ital NN] strong and Coulomb potentials yield a straight line in the charge radius vs energy plane which, unlike those of previous calculations, passes through the experimental datum. We find for all cases a polarization of the valence neutron in excess of 90%. This may make polarized [sup 6]LiD an attractive target for many nuclear physics purposes,more » since its neutrons are effectively 45% polarized.« less