You haven't given us enough information to get a very useful response, but, based on what we have, here is a more natural version.
"Fortunately, my collaboration with Peter has continued over recent years and we are now co-authoring a paper looking at (or which looks at) the impact of etc…"
Without knowing what follows I can't tell if it should be "impact" or "impacts", but my guess is that "impact" is the more likely.
not a teacher
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