  It was argued long ago that eta_b could be observed through the eta_b =>
Jpsi(=> mu+ mu-) Jpsi(=> mu+ mu-) decay chain. Recent calculations indicate
that the width of eta_b into two Jpsi is almost 3 orders of magnitude smaller
than the one into the D bar D*. We study the effects of final-state
interactions due to the D bar D* intermediate state on the Jpsi Jpsi final
state. We find that the inclusion of this contribution may enhance the
short-distance branching ratio up to about 2 orders of magnitude.
