Testing particle trapping in transition disks with ALMA P. Pinilla, N. van der Marel, L. M. Pérez, E. F. van Dishoeck, S. Andrews, T. Birnstiel, G. Herczeg, K. M. Pontoppidan and T. van Kempen A&A, 584 (2015) A16 Published online: 13 November 2015 DOI: 10.1051/0004-6361/201526655