Standard model and new physics contributions to K L and K S into four leptons Giancarlo D’Ambrosio, David Greynat and Grégory Vulvert Eur. Phys. J. C, 73 12 (2013) 2678 Published online: 11 December 2013 DOI: 10.1140/epjc/s10052-013-2678-1