6533b832fe1ef96bd129aa55

RESEARCH PRODUCT

Long-distance contributions to the K-L ->mu(+)mu(-) decay width

subject

description

The dispersive two-photon contribution to the K-L --> mu(+)mu(-) decay amplitude is analyzed, using chiral perturbation theory techniques and large-N-C considerations. A consistent description of the decays pi(0) --> e(+)e(-), eta --> mu(+)mu(-), and K-L --> mu(+)mu(-) is obtained. As a by-product, one predicts B(eta --> e(+)e(-)) = (5.8 +/- 0.2) X 10(-9) and B(K-L --> e(+)e(-)) = (9.0 +/- 0.4) X 10(-12).