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Study of the Decays KL -> pi+ pi- gamma and KL -> pi+ pi- e+ e- at KTeV

John Belz
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Abstract

We present new results on the related rare KL decay modes KL -> pi+ pi- gamma and KL -> pi+ pi- e+ e-. KTeV has performed the first direct measurement of the form factor for the "direct emission" component of KL -> pi+ pi- gamma decays, a quantity with ramifications for particular chiral models. In addition, the form factor and direct emission/inner bremsstrahlung branching ratio - also presented here - are important input parameters for the understanding of the planar-angle distribution of KL -> pi+ pi- e+ e- decays. Preliminary results indicating the presence of a T-violating asymmetry in the KL -> pi+ pi- e+ e- angular distribution are presented.

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John Belz. 1999-03-15. Study of the Decays KL -> pi+ pi- gamma and KL -> pi+ pi- e+ e- at KTeV. https://arxiv.org/abs/hep-ex/9903025

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