@article{b41d65c0cbcd437eb19080b72997671d,
title = "First observation and study of the K± → π±π0e+e− decay",
abstract = "The NA48/2 experiment at CERN reports the first observation of the K±→π±π0e+e− decay from an exposure of 1.7×1011 charged kaon decays recorded in 2003–2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR(K±→π±π0e+e−)=(4.24±0.14)×10−6. The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated.",
author = "{The NA48/2 collaboration} and Batley, {J. R.} and G. Kalmus and C. Lazzeroni and Munday, {D. J.} and Slater, {M. W.} and Wotton, {S. A.} and R. Arcidiacono and G. Bocquet and N. Cabibbo and A. Ceccucci and D. Cundy and V. Falaleev and M. Fidecaro and L. Gatignon and A. Gonidec and W. Kubischta and A. Maier and A. Norton and M. Patel and A. Peters and S. Balev and Frabetti, {P. L.} and E. Gersabeck and E. Goudzovski and P. Hristov and V. Kekelidze and V. Kozhuharov and L. Litov and D. Madigozhin and M. Misheva and N. Molokanova and I. Polenkevich and Yu Potrebenikov and S. Stoynev and A. Zinchenko and E. Monnier and E. Swallow and R. Winston and P. Rubin and A. Walker and P. Dalpiaz and C. Damiani and M. Fiorini and M. Martini and F. Petrucci and M. Savri{\'e} and M. Scarpa and H. Wahl and W. Baldini and {Cotta Ramusino}, A.",
note = "Funding Information: Funded by the UK Particle Physics and Astronomy Research Council, grant PPA/G/O/1999/00559.Supported by a Royal Society University Research Fellowship (UF100308, UF0758946).Supported by ERC Starting Grant 336581.Now at: Faculty of Physics, University of Sofia “St. Kl. Ohridski”, BG-1164 Sofia, Bulgaria, funded by the Bulgarian National Science Fund under contract DID02-22.Funded by the German Federal Minister for Education and research under contract 05HK1UM1/1.Funded by the German Federal Minister for Research and Technology (BMBF) under contract 056SI74.Funded by the Austrian Ministry for Traffic and Research under the contract GZ 616.360/2-IV GZ 616.363/2-VIII, and by the Fonds f{\"u}r Wissenschaft und Forschung FWF Nr. P08929-PHY. Publisher Copyright: {\textcopyright} 2018 The Author(s)",
year = "2019",
month = jan,
day = "10",
doi = "10.1016/j.physletb.2018.11.046",
language = "English (US)",
volume = "788",
pages = "552--561",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",
}