New Possibility of Solving the Problem of Lifetime Ratio $\tau ({\mathrm{\Lambda }}_b)\mathrm{/}\tau (B_d)$

We discuss the problem of the large discrepancy between the observed lifetime ratio of ${\mathrm{\Lambda }}_b$ to $B_d$ and the theoretical prediction obtained by the heavy quark effective theory. A new possibility of solving this problem is proposed from the viewpoint of operator product expansion and the lifetime ratio of ${\mathrm{\Omega }}_b$ to $B_d$ is predicted.