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arXiv · 1112.5184

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

Luigi Cappiello·Oscar Cata·Giancarlo D'Ambrosio·Dao-Neng Gao
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Abstract

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. This constitutes by itself a strong motivation for NA62 to study K^- decays in the future. We therefore provide a detailed study of different charge asymmetries and the corresponding estimated signals. Whenever possible, we make contact with the related processes K^+ -> pi^+ pi^0 gamma and K_L -> pi^+ pi^- e^+ e^- and discuss the advantages of K^+ -> pi^+ pi^0 e^+ e^- over them.

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Luigi Cappiello, Oscar Cata, Giancarlo D'Ambrosio, Dao-Neng Gao. 2011-12-21. K^+ -> pi^+pi^0e^+e^-: a novel short-distance probe. https://doi.org/10.1140/epjc%2Fs10052-012-1872-x

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