3-jet production at the Tevatron

Use MadGraph/MadEvent to obtain the distributions of $x_3,x_4$ where $x_i=2 E_i/M_{3j}$ are the energy fraction of the jets normalized as $x_3+x_4+x_5=2$, with $x_3>x_4>x_5$, in three-jet events. Consider $p\bar p$ collisions at 1.8 TeV of c.m.s. Set the minimum $p_T$ for the jets to 15 GeV, the maximum rapidity of $3.5$ and the $\Delta R=0.8$. Compare your results with the experimental data from CDF, Run I, shown in the Figure below.