LHCb and CMS combined data

(17 November 2014)

This figure has been extracted from this article. We will not comment the content of the write-up, but rather give some highlights of the technologies used to obtain this plot!

• A very rich statistical model had to be implemented for the final fit of the invariant mass of the B meson. RooFit provides all the building blocks for the modelling of the pdfs, errors and for the combination of the datasets.

• Notice the units of the axes: ROOT allows you to specify Latex code for the description of the quantities plotted. In order to obtain an expressive plot, carrying a message about the measurement and the data analysis being carried out, it is fundamental to have the freedom to be extremely precise when it comes to axes!

• Points for data, models for signal and background: clear and elegant line styles and colors are needed. The advanced graphics of ROOT provide all the building blocks to create a plot beautiful enough to end up on Nature. This is a rather technical remark but it is useful to underline how the transparency effect of the fill color of the two histograms can improve the clarity of the scientific result displayed by the plot.