This figure has been extracted from this article.
It is part of the results presented at the 2015 end-of-the-year jamboree. It illustrates studies of “high-multiplicity” proton collisions, where a hundred or more charged particles are produced, have shown indications that some particles are somehow “correlated” – i.e. associated together when they were created at the point of collision. This correlation manifests as a ridge seen in this plot along Δφ = 0.
In particular, this plot shows the ability of ROOT of visualizing high quality three dimensional graphics and complex formulas in the axis labels.