A theoretical prediction of the B-s meson lifetime difference

We present the results of a quenched lattice calculation of the operator ma trix elements relevant for predicting the B-s width difference. Our main re sult is (Delta Gamma (Bs)/Gamma (Bs)) = (4.7 +/- 1.5 +/- 1.6) x 10(-2), obt ained from tho ratio of matrix elements R(m(b)) = ((B) over bar (0)(s)\Qs\B -s(0)]/[(B) over bar (0)(s)\QL\B-s(0)) = -0.93(3)(-0.01)(+0.00) . R(m(b)) w as evaluated from the two relevant B parameters B-S((MS) over bar)(m(b)) = 0.86(2)(-0.02)(+0.02) and B-Bs((MS) over bar)(m(b)) = 0.91(3)(-0.06)(+0.00) , which we computed in our simulation.