K0−K¯0mixing in the six-quark model

Using the leading-logarithm approximation, strong-interaction corrections to $K^0-{\overline{K}}^0$ mixing in the six-quark model are computed in quantum chromodynamics. The full calculation involving the mixing of eight operators at some stages is done, as well as an approximate, much simpler calculation. Numerically, the exact and approximate results agree to high accuracy and both show that the corrections to the real and imaginary parts can be large. How to obtain the free-quark limit of these and other results is shown explicitly.