Probing the Majorana mass scale of right-handed neutrinos in mSUGRA F. Deppisch, H. Päs, A. Redelbach, R. Rückl and Y. Shimizu Eur. Phys. J. C, 28 3 (2003) 365-374 Published online: 14 April 2003 DOI: 10.1140/epjc/s2003-01184-6