Macroscopic quantum many-body tunneling of attractive Bose-Einstein condensate in anharmonic trap Sudip Kumar Haldar, Pankaj Kumar Debnath and Barnali Chakrabarti Eur. Phys. J. D, 67 9 (2013) 188 Published online: 12 September 2013 DOI: 10.1140/epjd/e2013-40008-7