HIDDEN STRUCTURE IN A LAGRANGIAN FOR HYPERFINE SPLITTING OF THE HEAVYBARYONS

We investigate the hyperfine splitting of the heavy baryons in the bou nd-state approach. We start with an ordinary relativistic Lagrangian w hich has been extensively used to discuss finite mass corrections to t he heavy limit predictions, It turns out that the dominant contributio n arises from terms which do not manifestly break the heavy spin symme try. The actual heavy spin violating terms are uncovered by carefully performing a 1/M expansion of this Lagrangian.