1999/08/12 by L.M. Sehgal, L. M. Sehgal, Sehgal, L. M.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle Detector Development and Performance #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9908338
8 pages including 1 figure, Talk at KAON 99 Conference, Chicago, June 21-26, 1999
arxiv created 1999/08/12 · openalex publication_date 1999/08/12 · arxiv updated 2009/11/30 · openalex created_date 2024/04/10 · openalex updated_date 2026/07/28
I review the theoretical basis of the prediction that the decay KL -> pi+ pi- e+ e- should show a large CP- and T-violation, a prediction now confirmed by the KTeV experiment. The genesis of the effect lies in a large violation of CP- and T-invariance in the decay KL -> pi+ pi- gamma, which is encrypted in the polarization state of the photon. The decay KL -> pi+ pi- e+ e- serves as an analyser of the photon polarization. The asymmetry in the distribution of the angle phi between the pi+ pi- and e+ e- planes is a direct measure of the CP-odd, T-odd component of the photon's Stokes vector. A complete study of the angular distribution can reveal further CP-violating features, which probe the non-radiative (charge-radius and short-distance) components of the KL -> pi+ pi- e+ e- amplitude.