LONG-DISTANCE CONTRIBUTION TO K-L-]L(+)L(-)

We revisit the calculation of the long distance contribution to K-L -- > mu(+)mu(-). We discuss this process within the framework of chiral p erturbation theory, and also using simple models for the K-L gammagam ma vertex. We argue that it is unlikely that this mode can be used to extract information on short distance parameters. The process K-L --> e(+)e(-) is also long-distance dominated and we find that B(K-L --> e (+)e(-)) approximate to 9 x 10(-12). (C) 1998 Elsevier Science B.V.