Software setup

Most of the analysis is done using specialised ROOT macros which will be discussed later. Some general infrastructure is, however, contained in the standard NA49 ROOT libraries (ROOT49). The main two components in this category are T49SumGaus , which implements the fit function and the group of classes T49Container , T49Index and T49DedxInfo which are used to store the $dE/dx$ histograms and the results of the fitting.

All of the $dE/dx$ software comes in two versions: one has 4 particle types: $p$, $K$, $\pi$ and $e$ while the other has deuterons as well, so 5 particle types. When making this transition, the parameters in the fit function were renumbered, so the two versions are incompatible. Make sure that you are using a consistent set of programs.