K^+ -> pi^+pi^0e^+e^-: a novel short-distance probe

Understand

We study the decay K^+ -> pi^+ pi^0 e^+ e^-, currently under analysis by the NA62 Collaboration at CERN.

• In particular, we provide a detailed analysis of the Dalitz plot for the long-distance, gamma^*-mediated, contributions (Bremsstrahlung, direct emission and its interference).
• We also examine a set of asymmetries to isolate genuine short-distance effects.
• While we show that charge asymmetries are not required to test short distances, they provide the best environment for its detection.