  Heavy ion collisions are rich and complex systems that involve different
aspects of QCD and electromagnetic phenomena. From head-on collisions to the
case in which the nuclei miss each other, many of QCD and photo-induced probes
are being actively investigated. In this contribution we briefly discuss both
of these different topics and some of the CMS results on top quark production
and vector meson photo-production, as well as the physics motivation to study
these processes are presented.
