Double ionization of helium by proton impact: from intermediate to high momentum transfer Marcelo J. Ambrosio, Lorenzo U. Ancarani, Antonio I. Gómez, Enzo L. Gaggioli, Darío M. Mitnik and Gustavo Gasaneo Eur. Phys. J. D, 71 5 (2017) 127 Published online: 25 May 2017 DOI: 10.1140/epjd/e2017-70713-x