  We study the Kondo effect in a quantum dot embedded in a mesoscopic ring
taking into account intradot spin-flip scattering $R$. Based on the finite-$U$
slave-boson mean-field approach, we find that the Kondo peak in the density of
states is split into two peaks by this coherent spin-flip transition, which is
responsible for some interesting features of the Kondo-assisted persistent
current circulating the ring: (1) strong suppression and crossover to a sine
function form with increasing $R$; (2) appearance of a "hump" in the
$R$-dependent behavior for odd parity. $R$-induced reverse of the persistent
current direction is also observed for odd parity.
