Long-distance contributions to the eta(b) -> J/psi J/psi decay

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