On the short-distance constraints from Kₗ,ₛ -> mu+ mu-

الأصل · EN

Motivated by new precise results on several Kₗ decays, sensitive to the Kₗ → γγ form factor, we present a new analysis of the Kₗ→ μ+μ- long-distance amplitude based on a semi-phenomenological approach. Particular attention is devoted to the evaluation of the uncertainties of this method and to the comparison with alternative approaches. Our main result is a conservative upper bound of 2.5 × 10⁻⁹ on B(Kₗ → μ+ μ-) short, which is compatible with the SM expectation and which provides significant constraints on new-physics scenarios. The possibility to extract an independent short-distance information from future searches on Kₛ → μ+ μ- is also briefly discussed.