Flavor Changing Kaon Decays from HyperCP: Measurements of the K+/- -> pi+/- mu+ mu- Branching Ratios

The Fermilab HyperCP collaboration is making precision studies of charged hyperon and kaon decays, as well as searches for rare and forbidden hyperon and kaon decays. We report here on measurements of the branching ratios of the flavor-changing neutral-current decays: K+/- -> pi+/- mu+ mu-, and compare our results to theoretical predictions. This is the first observation of the K- -> pi- mu+ mu- decay.
Presented at the XXXVIIth Rencontres de Moriond on Electroweak Interactions and Unified Theories, Les Arcs, France, 9-16 March 2002; 6 pages, 6 figures