The high rates of multi-parton interactions at the LHC can provide a unique
opportunity to study the multi-parton structure of the hadron. To this purpose
high energy collisions of protons with nuclei are particularly suitable. The
rates of multi-parton interactions depend in fact both on the partonic
multiplicities and on the distributions of partons in transverse space, which
produce different effects on the cross section in pA collisions, as a function
of the atomic mass number A. Differently with respect to the case of
multi-parton interactions in pp collisions, the possibility of changing the
atomic mass number provides thus an additional handle to distinguish the
diverse contributions. Some relevant features of double parton interactions in
pD collisions have been discussed in a previous paper. In the present paper we
show how the effects of double and triple correlation terms of the multi-parton
structure can be disentangled, by comparing the rates of multiple parton
interactions in collisions of protons with D, Tritium and 3He.Comment: 50 pages, 13 figure
