Sure. I imagine Google will easily give you more results but here's one: http://www.mckinsey.com/insights/organization/is_there_a_pay...

As has been said many times before, correlation is not causation though, and other studies have shown that the more females you have, the better a team performs so maybe we dont need diversity and just need more women. I do remember reading other articles about the benefits of racial diversity as well but I'm sure you won't have trouble finding them.