Sign ambiguity in the KΣ channel A. V. Anisovich, E. Klempt, V. A. Nikonov, A. V. Sarantsev and U. Thoma Eur. Phys. J. A, 49 12 (2013) 158 Published online: 24 December 2013 DOI: 10.1140/epja/i2013-13158-8